653 results for Doctoral, 2010

  • The rise and development of gangs in New Zealand

    Gilbert, Jarrod (2010)

    Doctoral thesis
    University of Canterbury Library

    Although gang behaviour was in evidence in early colonial New Zealand, the advent of modern gangs can be seen to have occurred in the post World War II period. Since this time, gangs have been heralded as a significant and often severe social problem, particularly as they pertain to issues of law and order. Initially, concerns regarding gangs were focused on their anti social activities and the occasional violent episode, but as many of the gangs became more established this focus broadened to include organised criminal activity. Whether it is images and stories of violent brawls, murders and rapes or, as has been more prominent in recent times, reports of profit driven crime, gang activity receives considerable media attention and thus gangs are afforded a high public profile. Given this profile, it is not surprising that gangs have been an important target for politicians and governments who have introduced various laws in an effort to counter them. Despite the attention paid to them, however, gangs have not been subjected to significant research in this country. Using a wide range of historical documents, ethnographic research and formal interviews, this thesis seeks to examine the rise of gangs in New Zealand and track their evolutionary development. It also focuses on how the community has responded to the issue of gangs, and how, in turn, the gangs have responded to that attention. The findings of this thesis will undoubtedly be surprising to many; despite gangs having a high profile, commonly held ‘knowledge’ of them has most often been learned by sensational media or political rhetoric and is consequently often removed from reality. Informed by many of the understandings gained from the plethora of international research, this thesis attempts to outline and give meaning to a hitherto untold story.

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  • Solution-Phase Synthesis of Nanoparticles and Growth Study

    Cheong, Soshan (2010)

    Doctoral thesis
    Victoria University of Wellington

    This thesis is concerned with solution-phase synthesis of nanoparticles and growth of nanoparticles in solution. A facile synthesis route was developed to produce nanoparticles of iron, iron carbide and ruthenium. In general, the synthesis involved the reaction/decomposition of a metal precursor in solution, in the presence of a stabilising agent, in a closed reaction vessel, under a hydrogen atmosphere. The crystallinity, crystal structure, morphology and chemical composition of the nanoparticles obtained were studied primarily by transmission electron microscopy (TEM), selected area electron diffraction (SAED), powder X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). Scanning quantum interference device magnetometry (SQUID) was used to characterise the magnetic properties of iron and iron carbide nanoparticles. In situ synchrotron-based XRD was employed to investigate the growth of platinum nanoparticles of different morphologies. The synthesis of iron and iron carbide nanoparticles was investigated at temperatures 80-160 °C. Syntheses at 130 °C and above produced mainly single-crystal α-Fe nanoparticles, whereas those at lower temperatures yielded products consisting of α-Fe and Fe₃C nanoparticles. Nanoparticles of larger than 10 nm oxidised on the surface leading to core/shell structures, and those of smaller size oxidised completely upon exposure to air. Core/shell nanoparticles of larger than 15 nm were observed to be stable under ambient conditions for at least a year, whereas those smaller in size underwent further oxidation forming core/void/shell structures. The magnetic properties of selected samples were characterised. The core/shell nanoparticles were shown to exhibit ferromagnetic behaviours, and saturation magnetisations were obtained at the range of 100-130 emu g⁻¹. Nanoparticle size and size distribution, and morphology were found to be a result of combined effect of precursor concentration and the relative stabiliser concentration. In general, high-precursor concentration resulted in less controlled reaction and produced large nanoparticle size and size distribution. Under the high-concentration condition, the use of stabilisers in reduced amount then led to a diverse range of morphologies, which include dimer, porous and branched structures. As for the synthesis of ruthenium nanoparticles, reactions of different precursors were investigated at temperatures ranging from room temperature to 140 °C. Highly crystalline ruthenium nanoparticles of different sizes and morphologies were obtained through different experimental conditions. The increase in nanoparticle size was found to be a result of increasing reaction temperature and/or decreasing stabiliser to ruthenium ratio. This trend was observed to be independent of the type of stabilisers and precursors used. The use of stabilisers with different binding characteristics has facilitated the formation of non-spherical nanoparticles; these include rod-like structures with high aspect ratios (of up to 12), hexagonal and truncated triangular plate-like structures, and tripods. The growth of faceted and branched structures of platinum nanoparticles was investigated by employing in situ XRD techniques. TEM was used to examine the intermediate structures. The two different morphologies were previously shown to be governed by precursor concentration. It was found that the growth in the low-concentration reaction was characteristic of a thermodynamically controlled regime, whereas that in the high-concentration reaction occurred at much greater rates under a kinetically controlled regime. Based on the observations obtained, different growth mechanisms were proposed and discussed. The former involved an oriented attachment mechanism, while the latter, a novel mechanism involving selective growth and etching processes. The results are followed by an overall discussion comparing and contrasting the various syntheses involved, and relating the results of syntheses to those of the growth studies.

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  • Chinese Immigrant Children in New Zealand Early Childhood Centres

    Guo, Karen Liang (2010)

    Doctoral thesis
    Victoria University of Wellington

    This research investigated the learning experiences of Chinese immigrant children in New Zealand early childhood centres with the aim of describing educational implications for early childhood professionals. A qualitative research approach was adopted using a multiple case study design. Eight Chinese immigrant children aged three to five years, their parents and their teachers participated in the study; the children were enrolled in six early childhood centres in a large urban area. Procedures of data gathering included child observations, and child, parent and teacher interviews. Data were analysed from phenomenological and sociocultural perspectives. The children's learning experiences, particularly languages and interpersonal relationships, were discussed from the perspectives of sociocultural theories. The concept of a learning community contributed to the analysis which was also influenced by the notions of cultural diversity and multiculturalism. A major theme of this research was the value of the culture of Chinese immigrant families to mediate the learning experiences of Chinese immigrant children in New Zealand early childhood centres. Familiar cultural tools and mediators provided important support for the children who were able to access them in their centres. The children's intention to drive their own learning experiences was also a salient feature. Evidence was documented that illustrated how learning and development were mediated by fulfilment of feelings of belonging, as well as the children's commitment to cross cultural boundaries. The Chinese immigrant children were active drivers of their own learning and capably negotiated and created the relationships between their family culture and that of their early childhood centre. Specific strategies they adopted to construct their own learning experiences were found to be significant in explaining the emergence of hybrid cultural tools which mediated the children's evolving development of appropriate repertoires of practice in their early childhood centres. This thesis contributes to the body of sociocultural research via the examination of children's creation of intercultural learning possibilities. It provides early childhood teachers with insights regarding how to enhance pedagogical policies, values and practices to more closely align with sociocultural frameworks, concepts of learning communities and cultural diversity. It is important that diverse cultural relations are appropriately established in the early childhood centres so that immigrant children can move between different cultures in order to generate a useful intercultural way of being for themselves.

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  • Tobacco smoke extract modulates activity and expression of monoamine oxidase and μ opioid receptor in cultured human neuroblastoma cells

    Lewis, Amy Jane (2010)

    Doctoral thesis
    Victoria University of Wellington

    Tobacco addiction is a major public health concern and is responsible for approximately five million deaths globally each year. Although most current smokers express a desire to quit, few are successful in their attempts. Nicotine is the primary neurobiologically active component in tobacco smoke and acts through the nicotinic acetylcholine receptor (nAChR) to sustain addiction. However, nicotine replacement therapies have proven to be remarkably ineffective at helping smokers quit. This indicates that nicotine alone cannot fully account for the intense and enduring nature of tobacco addiction. Previous research has provided strong evidence that monoamine oxidase (MAO) enzymes and the endogenous opioid system may also play a role in tobacco dependence. The present study compared and contrasted the influence of nicotine and the non-nicotine components of tobacco smoke on the enzyme activity of MAO-A and MAO-B. Gene expression of MAO and the mu opioid receptor (MOR) in SH-SY5Y human neuroblastoma and U-118 MG glioma cell lines was also investigated. Using a kynuramine-based enzymatic assay adapted and optimised for this study, the MAO inhibitory activity of tobacco-based samples were tested, including total particulate matter (TPM) extracts from a range of New Zealand tobacco products, Quest(R) nicotine-free cigarettes, and fluid from the RUYAN(R) Electronic cigarette. TPM from both standard tobacco and Quest(R) significantly inhibited MAO-A and MAO-B activity in vitro and in cultured cells. Differences between the types and brands of tobacco products were observed. TPM derived from loose-leaf tobacco inhibited MAO enzymes more potently than samples from manufactured cigarettes. This difference was attributed to a significantly higher tar:nicotine ratio in loose-leaf tobacco. Standard TPM and Quest(R) TPM also inhibited total MAO activity in SH-SY5Y cells treated for 24 hours; whereas the weak activity in U-118 MG remained unchanged. However, MAO activity was highly dependent on the cell culture conditions, with activity increasing in SH-SY5Y cells when treated with a 5-day exposure regimen. This finding was unique to the present study. The gene expression of MAO-A, MAO-B, and MOR was examined using a qRT-PCR assay. All three genes were significantly up-regulated by standard and denicotinized TPM extracts after a 5-day treatment regimen. This finding was correlated with an increase in protein abundance for MOR, but not MAO-A or MAO-B, as assayed by Western blot. Up-regulation of MAO and MOR gene expression was abolished when cells were treated with TPM extracts in conjunction with the nAChR antagonist mecamylamine, suggesting that up-regulation of MAO and MOR genes was dependent, at least in part, on nAChR signalling. Both standard TPM and TPM from denicotinized Quest(R) cigarettes induced inhibition of MAO and up-regulation of MAO and MOR gene expression. This demonstrates that non-nicotine compounds within tobacco smoke can significantly influence the behaviour of cultured neuronal cells. Further research is required to fully elucidate the mechanisms behind the MAO and MOR gene response, and a better understanding of these mechanisms may provide a framework for the development of novel smoking cessation therapies.

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  • Impact of Macro and Micro Governance Structures on Earnings Management

    Houqe, Muhammad Nurul (2010)

    Doctoral thesis
    Victoria University of Wellington

    This study examines the macro and micro level determinants of the quality of reported earnings. The prior literature suggests that both micro and macro variables impact on discretionary accruals choice in managing earnings. However, most of the studies on earnings management have been single country studies that have focussed only on micro variables as all firms within the samples examined have been subject to the same interplay of macro economic, legal, cultural and institutional frameworks. This study addresses this gap in the literature by using a sample of 156,906 firm year observations from 63 countries over the period 1998-2007 to examine the role of thirteen micro and macro variables in determining earnings quality. The macro variables studied include legal enforcement, political system, and control of corruption, culture and adoption of IFRS. Earnings management is estimated using the modified Jones model (Dechow et al. 1995) in a cross section (DeFond and Jiambalvo 1994; Francis et al. 1998). The results of the study indicate that macro and micro level variables have a strong impact on earnings management behaviour and thus earnings quality. The limits imposed by a country's legal, cultural and institutional setting on managerial discretionary accruals choices, strongly impact the quality of reported earnings. Future research on earnings management should therefore control both micro and macro level variables.

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  • Gravidographics: A Health Lifestyle Segmentation of Pregnant Women in Transition to First Time Motherhood

    Krisjanous, Jayne (2010)

    Doctoral thesis
    Victoria University of Wellington

    The purpose of this thesis is to contribute a new health psychographic/ lifestyle segmentation of pregnant women in New Zealand who are in transition to first time motherhood. It provides a better understanding of the make up of the market and the way it aggregates into health lifestyle segments. By using a wide selection of pre-existing and pregnancy related health and attitude dimensions, it complements existing understanding and classifications of pregnancy health lifestyle. First, the study richly describes pregnancy health behaviour within a representative cohort of pregnant women in a transitional lifestyle using a holistic framework. It takes into account lifestyle as made up of a combination of factors and underlying motivations. Furthermore, it establishes the application of 'lifestyle' as it is used in marketing as legitimate for the study of a transitional health lifestyle. The research is cross disciplinary, and for that reason, integrates two perhaps seemingly disparate (marketing and health) understandings of lifestyle, using a somewhat novel approach. It is inclusive of high risk pregnant women and a much less oft studied group, normal, healthy or low risk women. Second, a key component of this study is the seminal development of a segmentation typology that classifies women's health in pregnancy through a situation specific psychographic approach. This typology has been termed 'Gravidographics', and identifies segments of pregnant women, who have distinct or unique identifiers in regard to their pregnancy health lifestyle. This knowledge will be useful for health behaviour change through social marketing and also the design and targeting of products and services to specific groups of pregnant consumers. A third focus of the study is the examination of health lifestyle within the concept of life stage transition. As pregnancy marks the transit into a new life stage, there are many adaptations that need to be made, and several underlying factors influence the way such a journey is approached and achieved. The study is exploratory and the conceptual framework, derived predominantly from the marketing and health literature, guides the study and informs development of the data collection tools. Eight main research questions are explored. The study uses a survey design and is cross sectional, with quantitative enquiry the dominant logic. A survey using a self administered health psychographic questionnaire was distributed by Lead Maternity Carers to pregnant women in their care. A sample of 478 women was obtained for this stage of the study. Quantitative analysis was undertaken through descriptive statistics and bi-variate analyses. Secondly, two step clustering was undertaken to develop pregnancy health lifestyle clusters. Four health lifestyle segments were identified. These segments were then profiled against additional variables and data that led to rich descriptions of each segment. Several managerial recommendations are made that will assist in the delivery and positioning of maternity health goods and services particularly in regard to healthcare marketing and segmentation. Secondly, recommendations for future marketing communication strategies targeting pregnant women are made. Through this work, the study's ultimate aim; making an academic contribution to knowledge that will lead to improved health outcomes for mother and baby, has been achieved.

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  • A Diachronic Exploration of the Harvesting of the Marine Environment to a Distinctive New Zealand English Lexicon, 1796-2005

    Connor, Cherie Anne (2010)

    Doctoral thesis
    Victoria University of Wellington

    This study examines the lexical contribution the harvesting of the marine environment has made to a specific New Zealand English lexicon from 1795 to 2006. It draws on a range of written sources including annual government reports, periodicals, and unpublished manuscripts. The identified words are compiled into a wordlist based on historical principles, which includes definitions and numerous citations of usage. The sea coast was an area of early economic activity in New Zealand, with whaling constituting one of our earliest industries, and its practitioners some of the earliest English speaking settlers. It remains an area of continued cultural and economic significance. Therefore, the compiled wordlist provides not just a repository of long forgotten words, but an historical account of a living language in an area of continued significance to New Zealand. The body of New Zealandisms identified in this study are analysed systematically. Firstly, the lexical items are examined in seven 30 year time periods from 1796 to 2005 to determine changes in the number of innovations over time. The results show that the largest numbers of New Zealandisms were identified during the stages of early settlement, and in recent years. This suggests that New Zealand English continues to flourish at the lexical level, despite the threat which globalisation is perceived to pose to regional variation. Closer examination also reveals that lexical innovation in New Zealand is linked with New Zealand's growing sense of independence, and a dynamic orientation to the marine resource. In addition, a regional typology is applied to the identified lexis based on Deverson's (2000) model which shows when and how the innovation occurs, via coining and borrowing, or semantic shift. New words are examined to identify which word formation processes are the most productive. The categorisation reveals that lexical innovation in the area of marine harvesting is strongly focused on referents which are unique to New Zealand, and this is constant throughout the period studied. However, this reflects ongoing changes in the way that we label our unique referents, rather than the sheer number of unique referents. While new words are slightly more prevalent than semantic shift as a means of innovation in the marine domain, there is significant variation in this over time. That is, borrowing as a significant feature of lexical innovation during early European settlement is replaced in dominance by semantic shift as colonisation progresses. Since the 1970s, new words again dominate the form of lexical innovation, especially through the use of multi-word items employed to construct a complex management system. This impacts on the nature of the fisheries discourse and also our perception of the marine environment. The study of the contribution of the marine harvesting lexicon to New Zealand English creates a cultural document in an area of social and economic importance. It also provides a body of words which is available for analysis. The results of categorising the identified New Zealandisms contribute to our knowledge of the nature of New Zealand lexical innovation, and how it has changed throughout the European settlement of New Zealand.

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  • The State Collections of Colonial New Zealand Art: Intertwined Histories of Collecting and Display

    Rice, Rebecca (2010)

    Doctoral thesis
    Victoria University of Wellington

    This thesis explores the collecting and exhibiting of colonial art (before 1908) by New Zealand's state institutions: the Colonial (later Dominion) Museum; the Alexander Turnbull Library; and the National Art Gallery. It recovers evidence of the provenance of works of art within the state collections and accounts for acquisitions in terms of the ideological interests they serve, interests which reflect the intellectual concerns of the key individuals and the historical and political circumstances within which they worked. It examines how works of art were displayed in the institutions themselves, and in other exhibitions, including international exhibitions, both locally and abroad, from 1865 to 1940. This allows for analysis of the 'use' to which colonial art was put by the state, while investigation of the related contemporary discourse provides evidence of its reception and interpretation by critics and audience. This study employs a variety of analytical strategies, including: the place of class in relation to the colonial art world; the aesthetics of 'space' and the practicalities of exhibition in the colonial period; the shifting ground of what constitutes 'art', in particular 'New Zealand art', in the period under study; and the fluctuating, often problematic, status of much colonial art as both 'information' and as 'art'. Consequently, while informed by international scholarship, this thesis needed to adapt models formed for the explanation of metropolitan museology to accommodate the unique nature of the colonial experience in New Zealand. It concludes that, in contrast to many European institutions, the state was largely content to use New Zealand's art as information - as illustration of the colony's natural wonders and resources - and that no real attempt to define a national art history was initiated until the centennial celebrations of 1940. Significantly, this thesis does not just consider the evolution of one state institution. Rather, it recognises that the histories of New Zealand's cultural institutions - Museum, Gallery and Library - require a consideration of their development in relation to one another. This reveals a history of interconnectedness that reflects the complexity of colonial culture, and which ironically prefigures the challenge posed by colonial art to the postmodern descendent of the Museum and Gallery - the Museum of New Zealand Te Papa Tongarewa.

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  • From Alba to Aotearoa: Profiling New Zealand's Scots Migrants, 1840-1920

    Lenihan, Rebecca A. (2010)

    Doctoral thesis
    Victoria University of Wellington

    While New Zealand has been described as more Scottish than any other country beyond Scotland, and Scots consistently made up nearly 20 per cent of the immigrant population of New Zealand to 1920, as a group New Zealand's Scots migrants have remained relatively blurred. The distinctive national backgrounds of New Zealand's British migrants have seldom been recognised in general histories or in specialist studies of migration to the country, migrants having tended to be categorised as 'British' and 'Non-British', leading to what Akenson aptly described as the 'lumping of all white settlers into a spurious unity.' This thesis, conceived as part of a larger research project investigating the experiences and contributions of Scots in New Zealand, seeks to establish key characteristics of the Scottish migrants arriving between 1840 and 1920. Five core questions are addressed: 'from where in Scotland did they come?', 'who came?', 'when?', 'in what numbers?', and 'where did they settle?'. While previous studies have suggested partial answers to some of these questions, the present research offers a more full and detailed profile of New Zealand's Scots migrants than has previously been available. Critically, it takes the earlier findings further. Though the investigation has been based primarily upon statistical analysis of a genealogically-sourced database of 6,612 migrants, quantitative analysis has been supplemented by qualitative case studies. Comparison with a second set of data derived from death certificates has enabled a testing of the validity of genealogical data as a source for migration studies. In addition to the five central questions around which the thesis is structured, the study also addresses issues of internal migration within Scotland, emigration to other destinations prior to arrival in New Zealand, individual and generational occupational mobility, chain and cluster migration among Shetland migrants, and return migration.

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  • IT Project Governance and Stakeholder Conflict Resolution

    Johnstone, David (2010)

    Doctoral thesis
    Victoria University of Wellington

    IT projects have long been problematic, particularly as they have grown in size and complexity, frequently integrating several organisational functions, and often involving many stakeholders as a result. A common problem with large, complex IT projects is stakeholder conflict. Unless conflict is resolved effectively, there is a risk that the project will suffer delays and struggle to make progress. The purpose of this study is to investigate the role that environmental factors, such as culture, power, and history, play in conflict resolution. This study also examines how IT project governance can moderate the negative effects of environmental factors, and facilitate more successful conflict resolution. A systems perspective is used to represent the research framework. A positivist, qualitative research method using three case studies is used to examine the nature of conflict resolution in IT projects, comparing and contrasting outcomes. IT project governance arrangements (policies, authority structures and mechanisms) are found to be critical to the way stakeholder conflict is resolved

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  • Repression and Realism in Postwar American Literature 1945-1955

    Mercer, Erin (2010)

    Doctoral thesis
    Victoria University of Wellington

    This thesis focuses on the uncanny in literature produced in America during the first decade following World War II. The period between 1945 and 1955 was marked by repressive socio-political forces such as McCarthyism and cultural conformity which complicated the representation of what Philip Roth refers to as "demonic reality." I explore the ways in which the avoidance and minimisation of the unpleasant created a highly circumscribed version of postwar American life while also generating a sense of objectless anxiety. According to the theories of Sigmund Freud, repression inevitably stages a return registered as the "uncanny." Animism, magic, the omnipotence of thoughts, the castration complex, death, the double, madness, involuntary repetition compulsion, live burial and haunting are all deemed capable of provoking a particular anxiety connected to what lies beneath the surface of accepted reality. Although it is common to argue that fantasy genres such as science fiction and gothic represent the return of what is repressed, this thesis explores several realist novels displaying uncanny characteristics. The realist novels included here are uncanny not only because they depict weird automaton-like characters, haunting, and castration anxieties, thus exhibiting a conscious use of Freudian theory, but because the texts themselves act as the return of the repressed. Norman Mailer referred to this unsettling phenomenon when he described writing as the "spooky" art; spooky because although a writer might sit down to consciously write a particular story, another unwilled story might very well appear.

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  • Mechanisms in Carbon Nanotube Growth: Modelling and Molecular Dynamics Simulations

    Schebarchov, Dmitri (2010)

    Doctoral thesis
    Victoria University of Wellington

    A selection of nanoscale processes is studied theoretically, with the aim of identifying themechanisms that could lead to selective carbon nanotube (CNT) growth. Only mechanisms relevant to catalytic chemical vapour deposition (CVD) are considered. The selected processes are analysed with classical molecular dynamics (MD) simulations and continuum modelling. The melting and pre-melting behaviour of supported nickel catalyst particles is investigated. Favourable epitaxy between a nanoparticle and the substrate is shown to significantly raise themelting point of the particle. It is also demonstrated that substrate binding can induce solid-solid transformations, whilst the epitaxy may even determine the orientation of individual crystal planes in supported catalysts. These findings suggest that the substrate crystal structure alone can potentially be used to manipulate the properties of catalyst particles and, hence, influence the structure of CNTs. The first attempt at modelling catalyst dewetting, a process where the catalyst unbinds from the inner walls of a nucleating nanotube, is presented. It is argued that understanding this process and gaining control over itmay lead to better selectivity in CNT growth. Two mutually exclusive dewetting mechanisms, namely cap lift-off and capillary withdrawal, are identified and then modelled as elastocapillary phenomena. The modelling yields an upper bound on the diameter of CNTs that can stem from a catalyst particle of a given size. It is also demonstrated that cap lift-off is sensitive to cap topology, suggesting that it may be possible to link catalyst characteristics to the structural properties of nucleating CNTs. However, a clear link to the chiral vector remains elusive. It is shown that particle size, as well as binding affinity, plays a critical role in capillary absorption and withdrawal of catalyst nanoparticles. This size dependence is explored in detail, revealing interesting ramifications to the statics and dynamics of capillary-driven flows at the nanoscale. The findings bear significant implications for our understanding of CNT growth from catalyst particles, whilst also suggesting new nanofluidic applications and methods for fabricating composite metal-CNT materials.

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  • Feature Manipulation with Genetic Programming

    Neshatian, Kourosh (2010)

    Doctoral thesis
    Victoria University of Wellington

    Feature manipulation refers to the process by which the input space of a machine learning task is altered in order to improve the learning quality and performance. Three major aspects of feature manipulation are feature construction, feature ranking and feature selection. This thesis proposes a new filter-based methodology for feature manipulation in classification problems using genetic programming (GP). The goal is to modify the input representation of classification problems in order to improve classification performance and reduce the complexity of classification models. The thesis regards classification problems as a collection of variables including conditional variables (input features) and decision variables (target class labels). GP is used to discover the relationships between these variables. The types of relationship and the ways in which they are discovered vary with the three aspects of feature manipulation. In feature construction, the thesis proposes a GP-based method to construct high-level features in the form of functions of original input features. The functions are evolved by GP using an entropy-based fitness function that maximises the purity of class intervals. Unlike existing algorithms, the proposed GP-based method constructs multiple features and it can effectively perform transformational dimensionality reduction, using only a small number of GP-constructed features while preserving good classification performance. In feature ranking, the thesis proposes two GP-based methods for ranking single features and subsets of features. In single-feature ranking, the proposed method measures the influence of individual features on the classification performance by using GP to evolve a collection of weak classification models, and then measures the contribution of input features to the making of good models. In ranking of subsets of features, a virtual structure for GP trees and a new binary relevance function is proposed to measure the relationship between a subset of features and the target class labels. It is observed that the proposed method can discover complex relationships - such as multi-modal class distributions and multivariate correlations - that cannot be detected by traditional methods. In feature selection, the thesis provides a novel multi-objective GP-based approach to measuring the goodness of subsets of features. The subsets are evaluated based on their cardinality and their relationship to target class labels. The selection is performed by choosing a subset of features from a GP-discovered Pareto front containing suboptimal solutions (subsets). The thesis also proposes a novel method for measuring the redundancy between input features. It is used to select a subset of relevant features that do not exhibit redundancy with respect to each other. It is found that in all three aspects of feature manipulation, the proposed GP-based methodology is effective in discovering relationships between the features of a classification task. In the case of feature construction, the proposed GP-based methods evolve functions of conditional variables that can significantly improve the classification performance and reduce the complexity of the learned classifiers. In the case of feature ranking, the proposed GP-based methods can find complex relationships between conditional variables and decision variables. The resulted ranking shows a strong linear correlation with the actual classification performance. In the case of feature selection, the proposed GP-based method can find a set of sub-optimal subsets of features which provids a trade-off between the number of features and their relevance to the classification task. The proposed redundancy removal method can remove redundant features from a set of features. Both proposed feature selection methods can find an optimal subset of features that yields significantly better classification performance with a much smaller number of features than conventional classification methods.

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  • CD4 T Cell Responses in Lung Tissue and Their Role in Th2 Protective Immunity

    Harvie, Marina Catherine Goudie (2010)

    Doctoral thesis
    Victoria University of Wellington

    The acquisition of protective immunity is a critical feature of the immune system. It is the unique ability of the adaptive immune response to generate and maintain long-lived antigen specific memory cells, which is the key to preventing reinfection and achieving the goal of protective immunity. The importance of secondary lymphoid tissue (such as lymph nodes) as a site of effector CD4 T cell responses and the generation, dissemination and maintenance of memory CD4 T cells is well accepted. However, a key research area needing investigation is the basic biology of the CD4 T cell, particularly the recirculation, distribution and maintenance of CD4 T cells at sites throughout the body. To address these issues we used Nippostrongylus brasiliensis as a model of CD4 mediated protective immunity, combined with G4/IL-4 reporter mice. We show that the lung environment is critical for the priming of CD4 T cells and conferring protective immunity. In contrast to others we find no protective role for the CD4 T cell population of the skin and only a minor role for the population within the gut. In a separate study we used the drug fingolimod (FTY720) to block the cellular trafficking between lymph node and lung tissue during immune responses. Interestingly, our findings show that protection against N. brasiliensis infection is maintained when CD4 T cell recirculation between the lung and lymph node is blocked. Furthermore, we reveal that peripheral lung residing CD4 T cells are sufficient for conferring protective immunity in the N. brasiliensis model, generating support for the model of effector lymphoid tissue. When N. brasiliensis experienced CD4 T cells were localised to the lung by intranasal adoptive transfer they were able to confer protection against infection in otherwise naive animals, as early as 48 hours post infection. The most striking finding of this work is the discovery that memory CD4 T cells residing in the lung that are sufficient to confer protection against reinfection. Identifying the factors in the lung and lymph node that induce and support this CD4 T cell subset will be an important area of future research given its high relevance to the design of vaccines against parasite infections.

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  • Exploring the Lyric-Dramatic Interaction in the Work of T.S. Eliot

    Coelho, Patrick Prashant (2010)

    Doctoral thesis
    Victoria University of Wellington

    T. S. Eliot's fascination with the interaction between the lyric and the dramatic is evident from the fact that his poetry was often dramatic even before he began to write verse drama. Part of the reason for this interaction in Eliot was a kind of radical modernism that ensured a return to a primitivism where there was little distinction between the lyric and the dramatic. In this thesis I argue that this interaction is central to the nature of Eliot's creative work. The need for an interaction between the lyric and dramatic meant that The Waste Land (1922) possessed several dramatic qualities making it a precursor to Eliot's entry into the realm of poetic drama with the play, Sweeney Agonistes (1932). As part of my thesis, I conducted theatre workshops of the first two parts of The Waste Land in order to discover what dramatic elements emerged from the text and how their presence affected the lyric-dramatic interaction in the work, something which can surface only through performance. I argue that The Waste Land and Sweeney Agonistes occupy critical spaces in the mapping of the lyric-dramatic interaction in Eliot's creative oeuvre. The intensity of the lyric-dramatic interaction in Eliot's poetry builds up to a moment where he comes extremely close to drama in The Waste Land moving him to ultimately write his first play, Sweeney Agonistes. While Eliot's works after these two texts continue to exhibit characteristics of this lyric-dramatic interaction, the nature of this interaction undergoes a transformation after Eliot's conversion, manifesting itself in his religious poetry and drama which turns out to be a cul-de-sac in his experimentations. The intensity of this interaction in his work then gradually reduces to a point where the lyric and the dramatic no longer overlap especially after Eliot's first commercially successful play, The Cocktail Party (1949). By examining the reasons for the slow disassociation of these two crucial elements in Eliot's later work, I aim to stress the centrality of The Waste Land and Sweeney Agonistes to the lyric-dramatic trajectory in his work.

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  • Divisible Statistics and Their Partial Sum Processes: Asymptotic Properties and Applications

    Wu, Haizhen (2010)

    Doctoral thesis
    Victoria University of Wellington

    Divisible statistics have been widely used in many areas of statistical analysis. For example, Pearson's Chi-square statistic and the log-likelihood ratio statistic are frequently used in goodness of fit (GOF) and categorical analysis; the maximum likelihood (ML) estimators of the Shannon's and Simpson's diversity indices are often used as measure of diversity; and the spectral statistic plays a key role in the theory of large number of rare events. In the classical multinomial model, where the number of disjoint events N and their probabilities are all fixed, limit distributions of many divisible statistics have gradually been established. However, most of the results are based on the asymptotic equivalence of these statistics to Pearson's Chi-square statistic and the known limit distribution of the latter. In fact, with deeper analysis, one can conclude that the key point is not the asymptotic behavior of the Chi-square statistic, but that of the normalized frequencies. Based on the asymptotic normality of the normalized frequencies in the classical model, a unified approach to the limit theorems of more general divisible statistics can be established, of which the case of the Chi-square statistic is simply a natural corollary. In many applications, however, the classical multinomial model is not appropriate, and an extension to new models becomes necessary. This new type of model, called "non-classical" multinomial models, considers the case when N increases and the {Pni} change as sample size n increases. As we will see, in these non-classical models, both the asymptotic normality of the normalized frequencies and the asymptotic equivalence of many divisible statistics to the Chi-square statistic are lost, and the limit theorems established in classical model are no longer valid in non-classical models. The extension to non-classical models not only met the demands of many real world applications, but also opened a new research area in statistical analysis, which has not been thoroughly investigated so far. Although some results on the limit distributions of the divisible statistics in non-classical models have been acquired, e.g., Holst (1972); Morris (1975); Ivchenko and Levin (1976); Ivchenko and Medvedev (1979), they are far from complete. Though not yet attracting much attention by many applied statisticians, another advanced approach, introduced by Khmaladze (1984), makes use of modern martingale theory to establish functional limit theorems of the partial sum processes of divisible statistics successfully. In the main part of this thesis, we show that this martingale approach can be extended to more general situations where both Gaussian and Poissonian frequencies exist, and further discuss the properties and applications of the limiting processes, especially in constructing distribution-free statistics. The last part of the thesis is about the statistical analysis of large number of rare events (LNRE), which is an important class of non-classical multinomial models and presented in numerous applications. In LNRE models, most of the frequencies are very small and it is not immediately clear how consistent and reliable inference can be achieved. Based on the definitions and key concepts firstly introduced by Khmaladze (1988), we discuss a particular model with the context of diversity of questionnaires. The advanced statistical techniques such as large deviation, contiguity and Edgeworth expansion used in establishing limit theorems underpin the potential of LNRE theory to become a fruitful research area in future.

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  • Characterisation, Manipulation and Directed Evolution of Non-Ribosomal Peptide Synthetase Enzymes

    Owen, Jeremy George (2010)

    Doctoral thesis
    Victoria University of Wellington

    Non-ribosomal peptide synthetases (NRPS) are large, modular enzymes that synthesise biologically active secondary metabolites from amino acid precursors without the need for a nucleic acid template. NRPS play an integral role in microbial physiology and also have potential applications in the synthesis of novel peptide molecules. Both of these aspects are examined in this thesis. Under conditions of iron starvation Pseudomonas syringae synthesises siderophores for active uptake of iron. The primary siderophore of P. syringae is pyoverdine, a fluorescent molecule that is assembled from amino acid (aa) precursors by NRPS. Five putative pyoverdine NRPS genes in P. syringae pv. phaseolicola 1448a (Ps1448a) were identified and characterised in silico and their role in pyoverdine biosynthesis was confirmed by gene knockout. Creation of pyoverdine null Ps1448a enabled identification of a previously uncharacterised temperatureregulated secondary siderophore, achromobactin, which is NRPS independent and has lower affinity for iron. Pyoverdine and achromobactin null mutants were characterised in regard to iron uptake, virulence and growth in iron-limited conditions. Determination of the substrate specificity for the seven adenylation (A) domains of the Ps1448a pyoverdine sidechain NRPS was also attempted. Although ultimately unsuccessful, these attempts provided a rigorous assessment of methods for the expression, purification and biochemical characterisation of Adomains. The Ps1448a NRPS were subsequently employed in domain swapping experiments to test condensation (C) domain specificity for aa substrates during peptide formation in vivo. Experiments in which the terminal C- and/or A-domain of the Pseudomonas aeruginosa (PAO1) pyoverdine NRPS system were replaced with alternative domains from Ps1448a and PAO1 were consistent with previous in vitro observations that C-domains exhibit strong sidechain and stereo-selectivity at the downstream aa position, but only stereo-selectivity at the upstream aa position. These results prompted investigation into the role of inter-domain communication in NRPS function, to test the hypothesis that the thiolation (T) domain enters into specific interactions with other domains, which might provide an alternative explanation for the diminished activity of recombinant NRPS enzymes. A recently characterised single-module NRPS, bpsA, was chosen as a reporter gene for these experiments based on its ability to generate blue pigment in Escherichia coli. Substitution of the native bpsA T-domain consistently impaired function, consistent with the hypothesis. It was shown that directed evolution could be applied to restore function in substituted T-domains. Mutations that restored function were mapped in silico, and a structural model for interaction between the thioester (TE) and T-domain of BpsA was derived. The utility of bpsA for discovery and characterisation of phosphopantetheinyl transferase (PPTase) enzymes was also investigated. In vivo and in vitro assays for determination of PPTase activity were developed and a high-throughput screen for discovery of new PPTases in environmental DNA libraries was successfully implemented.

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  • Impact of Macro and Micro Governance Structures on Earnings Management

    Houqe, Muhammad Nurul (2010)

    Doctoral thesis
    Victoria University of Wellington

    This study examines the macro and micro level determinants of the quality of reported earnings. The prior literature suggests that both micro and macro variables impact on discretionary accruals choice in managing earnings. However, most of the studies on earnings management have been single country studies that have focussed only on micro variables as all firms within the samples examined have been subject to the same interplay of macro economic, legal, cultural and institutional frameworks. This study addresses this gap in the literature by using a sample of 156,906 firm year observations from 63 countries over the period 1998-2007 to examine the role of thirteen micro and macro variables in determining earnings quality. The macro variables studied include legal enforcement, political system, and control of corruption, culture and adoption of IFRS. Earnings management is estimated using the modified Jones model (Dechow et al. 1995) in a cross section (DeFond and Jiambalvo 1994; Francis et al. 1998). The results of the study indicate that macro and micro level variables have a strong impact on earnings management behaviour and thus earnings quality. The limits imposed by a country's legal, cultural and institutional setting on managerial discretionary accruals choices, strongly impact the quality of reported earnings. Future research on earnings management should therefore control both micro and macro level variables.

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  • Sex Offenders' Relationship Frames (SORF): A Qualitative Analysis of Value-laden Cognition in Child Sex Offenders

    Navathe, Shruti (2010)

    Doctoral thesis
    Victoria University of Wellington

    Over the past decades, sex offenders' cognition, specifically their cognitive distortions, have been the focus of extensive research. Traditionally, cognitive distortions have been described as any statements provided by the offender that justify, minimise, or excuse offending (Abel, et al., 1984). Recent research highlighted a need to expand current understanding of cognitive distortions with regards to value, affect and function. The Judgement Model of Cognitive Distortions (Ward, Gannon and Keown, 2006) argued for greater examination of beliefs, values, actions, and their interaction with each other. The current study examined the role played by values within the context of sex offenders' reasoning and decision-making processes. It also sought to understand the ways in which offenders' accounted for their offending, whether it was irrational, and if so, in what way. The research was qualitative, and used interviews gained from a sample of 27 adult, male, treated, child sexual offenders from within New Zealand. Grounded theory methodology (Strauss and Corbin, 1998) was used to create a data-driven model of offenders' reasoning and decision-making, within the context of offending. Results indicated that values were an important part of the offenders' cognition, central to their sense of self, and critical to their perception of the world around them. Values were closely related to how offenders framed their relationship with their victims. Based on the clustering of values, the Sexual Offender Relationship Frames Model (SORF) emerged. This was used to understand and illustrate different pathways to offending using case-studies from the sample. The results have been evaluated within the context of existing literature on the study of sexual offending. Clinical implications, limitations, and practical applications are discussed.

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  • Selves and Spaces in Science Fiction

    Davidson, Brett (2010)

    Doctoral thesis
    Victoria University of Wellington

    This thesis proposes a critical framework by which science fiction can be read as an indicator of significant trends and debates in science and culture. It takes as its starting point Brian Aldiss's statement that science fiction's purpose is to articulate in fictional form a definition of humanity and its status in the universe that will stand in the light of science. Science fiction exists as a means by which scientific concepts are constructed as cultural interpretations, and as both have changed significantly over the period from the emergence of the genre in the mid nineteenth century through the twentieth century, analysis of science-fictional forms and practices can reveal the processes of their evolution. A critical framework is constructed based on Aldiss' definition, identifying first, a construction of selfhood and spatiality - physical and metaphysical - as being fundamental, and secondly, identifying the emergence and evolution of major 'Orders' that take different approaches to key issues and which engage with each other both antagonistically and creatively. The thesis begins with an investigation of the cultural construction of space and then covers the emergence of science fiction as it relates to the project to define humanity and its standing in the universe in a manner consistent with science. Three Orders and their emergence are then described according to their architectonic schemae and their epistemological and creative processes. The first is the Modernist Order, based on Cartesian spatiality and mind-body dualism and empirical scientific practice. The second, which emerged as an attempt to synthesise modern science with traditional culture, is the Neohumanist Order. The third, still very much in flux, is the Posthumanist Order, which is very much inspired both by postmodernism and cybernetics. The three following chapters deal with the Orders in turn, selecting exemplary texts from their emergent and developed (or developing) stages, suggesting also the points in the development of each where another Order has disengaged and emerged in its own right. Because science and culture evolve over time, examination of the Orders is intrinsically linked to a concept of science fiction as being an ongoing discourse, each selected text is interpreted as being a response to a particular issue at a particular cultural moment, but nonetheless connected to predecessor and successor texts that represent a line of argument pursued over time within and between Orders. The Orders are not hermetic by any means, and their most enlightening aspects can be their varying treatment of a common concept. The cyborg furnishes an excellent example, being treated differently by each of the Orders as it is an image of the integration of humanity and technology. Issues such as self, body, boundary, location, the other and communication are all represented in the cyborg and the next two chapters discuss the cyborg as treated by different Orders, in the first case, as a body and in the second case, as an inhabitant and creation of architectonics and culture. The conclusion then discusses the current state of affairs regarding the system of Orders as a critical method. It is shown that 'impure' texts that contain aspects of each of the Orders do not negate their usefulness, but rather demonstrate it as texts (and postmodern texts in particular) provide stages on which the Orders can be displayed engaging with each other.

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