586 results for Doctoral, 2009

  • Open population capture-recapture models and diabetes in Otago

    Cameron, Claire (2009)

    Doctoral thesis
    University of Otago

    xiv, 207 leaves :ill., ; 30 cm Includes bibliographical references. University of Otago department: Mathematics and Statistics

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  • Antimicrobial activity of functional food ingredients focusing on manuka honey action against Escherichia coli : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering and Technology at Massey University, Auckland, New Zealand

    Rosendale, Douglas Ian (2009)

    Doctoral thesis
    Massey University

    The goal of this research was to identify functional food ingredients/ingredient combinations able to manage the growth of intestinal microorganisms, and to elucidate the mechanisms of action of the ingredient(s). By developing a high-throughput in vitro microbial growth assay, a variety of preselected ingredients were screened against a panel of bacteria. Manuka honey UMF(TM) 20+ and BroccoSprouts(R) were identified as the most effective at managing microbial growth, alone and in combination. Manuka honey was particularly effective at increasing probiotic growth and decreasing pathogen growth. Testing of these two ingredients progressed to an animal feeding trial. Here, contrary to the in vitro results, it was found that no significant in vivo effects were observed. All honeys are known to be antimicrobial by virtue of bee-derived hydrogen peroxide, honey sugar-derived osmotic effects, and the contribution of low pH and the other bioactive compounds present, hence their historical usage as an antiseptic wound dressing. The in vitro antimicrobial effect of manuka honey has currently been the subject of much investigation, primarily focusing on the Unique Manuka Factor (UMF), recently identified as methylglyoxal, a known antimicrobial agent. This work has taken the novel approach of examining the effects of all of the manuka honey antimicrobial constituents together against Escherichia coli, in order to fully establish the contribution of these factors to the observed in vitro antimicrobial effects. For the first time, it has been demonstrated that the in vitro antimicrobial activity of manuka honey is primarily due to a combination of osmotically active sugars and methylglyoxal, both in a dose-dependent manner, in a complex relationship with pH, aeration and other factors. Interestingly, the manuka honey was revealed to prevent the antimicrobial action of peroxide, and that whilst methylglyoxal prevented E. coli growth at the highest honey doses tested, at low concentrations the osmotically active sugars were the dominant growth-limiting factors. Contrary to the literature, it was discovered that methylglyoxal does not kill E. coli, but merely extended the lag phase of the organism. In conjunction with the lack of antimicrobial activity in vivo, this is a landmark discovery in the field of manuka honey research, as it implies that the value of manuka honey lies more towards wound dressing applications and gastric health than as a dietary supplement for intestinal health.

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  • Extraction of High-Value Minor Proteins from Milk

    Billakanti, Jaganmohan (2009)

    Doctoral thesis
    University of Canterbury Library

    Various methods for extraction and analysis of high value minor proteins (lactoferrin, lactoperoxidase and immunoglobulins) directly from raw milk were explored. Extraction, purification and analysis of high-value minor proteins directly from milk without pre-treatment are major challenges for dairy industry, largely due to the complexity of milk and the presence of colloidal solids (casein micelles and milk fat globules). To overcome some of these challenges, this work focused on three main objectives: 1) characterization of cryogel monolith chromatography for purification of lactoferrin (LF) and lactoperoxidase (LP) directly from raw milk in single step, 2) identification and characterization of Protein A Mimetic affinity ligands for purification of immunoglobulins (Igs) from milk and 3) development and validation of a surface plasmon resonance method for simultaneous quantification of five whey proteins in multiple samples. Results portrayed the possibility of 40–50 column volumes of various milk samples (whole milk, skim milk and acid whey) to pass through a 5 mL cryogel monolith chromatography column at 525 cm hr⁻¹ without exceeding its pressure limits if the processing temperature is maintained around 35–37°C. Ideally, this should be the milk secretion temperature. The dynamic binding capacity obtained for the cryogel matrix (2.1 mg mL⁻¹) was similar to that of the binding capacity (2.01 mg mL⁻¹) at equilibrium with 0.1 mg mL⁻¹ of lactoferrin in the feed samples. Lactoferrin and lactoperoxidase was selectively bound to the cryogel column with trivial leakage in flowthrough fractions. Lactoferrin was recovered from elution fractions with a yield of 85% and a purity of 90%. These results, together with the ease of manufacture, low cost and versatile surface chemistry of cryogels suggest that they may be a good alternative to packed-bed chromatography for direct capture of proteins from milk, provided that the binding capacity can be increased. A Protein A Mimetic (PAM) hexapeptide (HWRGWV) peptide ligand that binds to the Fc portion of antibody molecules was explored for affinity purification of immunoglobulins from milk. The peptide has the ability to purify IgG from various milk and whey samples with a purity of greater than 85% in single step. More than 90% bound IgG was recovered with 0.2 M acetate buffer at pH 4.0 and total column regeneration was successfully achieved by 2.0 M guanidine-HCl. At 9.0 mg mL⁻¹ of IgG feed concentration, an equilibrium binding capacity of 21.7 mg mL⁻¹ and dynamic binding capacity of approximately 12.0 mg mL⁻¹ of resin was obtained. Recoveries and yields of IgG were significantly influenced by the feed IgG concentration. PAM hexamer ligand also contributed a significant amount of cross-reactivity with casein, glycomacropeptides and β-lactoglobulin proteins, however majority of these proteins were recovered in the regeneration step, except β-lactoglobulin, which co-eluted with IgG. Higher IgG concentration in feed vastly reduced the amount of cross-reactivity whilst increasing the recoveries and purities in the final product. PAM affinity ligands also showed interactions towards other classes of bovine immunoglobulins. These findings established the possibility of using PAM hexamer peptide as an alternative to conventional Protein A/G affinity chromatography for the isolation of Igs from milk in single step process. A surface plasmon resonance (SPR) method was developed for simultaneous, quantitative determination of commercially important whey proteins in raw and processed milk samples, whey fractions and various milk-derived products, with six samples per assay. Immobilized antibody stability and reproducibility of analyses were studied over time for 25 independent runs (n=300), giving a relative standard deviation (RSD) of <1 RU). Regeneration of immobilised antibodies with glycine at pH 1.75 was determined to be optimal for maintaining the SPR response between samples. This method compared and validated well with reversed phase high performance liquid chromatography (RP-HPLC) and standard enzyme-linked immunosorbent assays (ELISA).

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  • The Charitable Purposes Exemption from Income Tax:Pitt to Pemsel 1798-1891

    Gousmett, Michael Joseph (2009)

    Doctoral thesis
    University of Canterbury Library

    Abstract In the Assessed Taxes Act 1798, and the Duties upon Income Act 1799, William Pitt the Younger provided exemptions from those taxes for charitable institutions. However, the legislation failed to provide a definition of charitable purposes with respect to either Assessed Taxes or Duties upon Income. The problems for charitable institutions began when Addington introduced deduction at source in 1803, thus catching charitable institutions in the tax net by requiring them to claim refunds of Income Tax that had been deducted from their non-voluntary income. To deal with the issues arising from such claims, Pitt created the Special Commissioners in 1805. The Duties upon Income Act 1799 and its successors were only intended as temporary war-time taxes, and Income Tax was eventually repealed in 1816 once peace with France had been achieved. However, Peel reintroduced Income Tax in 1842, based on the earlier Income Tax Acts. Once again, Income Tax was intended only as a short-term fiscal measure, but that was not to be and, during the course of the Nineteenth Century, the Income Tax became a permanent fixture of the legislative calendar. However, the issue of what was understood by the term “charitable purposes” with respect to Income Tax became an issue which, it was suggested in 1863, Parliament should resolve. That was not to be, and it was not until 1891 that Lord Macnaghten, in Commissioners for the Special Purposes of the Income Tax v Pemsel [1891] AC 531 laid down the four principal divisions of charity that continue to dominate charity case law in the Twenty-First Century. Until then, the exemption of charitable institutions from Income Tax had been a contentious issue. Anthony Highmore, a London lawyer who was also very active in a number of London’s charities in the late Eighteenth and early Nineteenth Centuries until his death in 1829, proposed in 1786, that charities should be exempt from all forms of taxation. In 1863 Gladstone unsuccessfully challenged the exemption of charitable institutions from Income Tax, arguing that income other than voluntary donations should be taxed, and that governments should decide which charitable institutions were worthy of direct government funding. However, charity case law continued to influence the decisions of the Special Commissioners until ultimately in 1891 Pemsel resolved the issue in a case which continues to resonate in the Twenty-first Century. The question that this Thesis seeks to answer is, what was the rationale for the charitable purposes exemption from Income Tax that Pitt had provided in his Income Tax Acts? I propose that the rationale was not founded in fiscal policy, or charity case law, but in social policy as influenced by the Evangelicals of late Eighteenth Century London, predominantly William Wilberforce and Hannah More, who were close friends of William Pitt the Younger.

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  • The Extended Decision Model

    Christensen, Darren Robert (2009)

    Doctoral thesis
    University of Canterbury Library

    The quantification of choice has been a major area of research for behavioural scientists for several decades. This is, in part, due to the discovery of the matching law (Herrnstein, 1961) which stipulates that relative response rates on concurrently available alternatives “match” the available relative reinforcement rates. This theoretical construct has been developed to describe response allocation in more complex situations, such as concurrent chains, and successfully describes both human and non-human behaviour. Typically, this phenomenon becomes evident when behaviour settles at an asymptote after several sessions of training where contingencies are held constant, and is often called “steady-state” behaviour. However, a fundamental question still remains: what causes matching – that is, what are the underlying momentary process(es) that produce matching? Researchers have suggested that what is necessary to answer this question is to take a molecular approach to the analysis of choice behaviour, thereby assessing choice in transition (Grace, 2002a). Recently, a new model of choice acquisition has been developed that appears to offer promise. It combines two separate mechanisms; a “winner-takes-all” categorical discrimination, and a linear-operator acquisition process (Grace & McLean, 2006). The initial results suggest this model could provide an alternative explanation for what underlies matching – that two separate processes are cooccurring in the acquisition of choice behaviour – allowing response allocation to be either linear or non-linear. This thesis extends the Grace and McLean model to include the situation of response strength ‘carrying-over’ from session to session to describe the process of acquisition gradually accumulating with experience. Moreover, additional assumptions have been added to describe temporal phenomena 2 and presumed discounting of previous experience on current choice behaviour. A steady-state version of the extended model was derived and, when fitted to published data sets, describes choice behaviour equally well when compared to existing models of steady-state choice. As a consequence of these additions, the Extended Decision Model (EDM) predicts a unique response allocation pattern – choice behaviour follows a bitonic function when initial-link durations were increased and the terminallink delays were held constant. The results from experiments presented in this thesis support this prediction, whilst steady-state analyses found the EDM was parameter invariant – differences between parameters from two schedule types across several archival data sets were non-significant, while existing steady-state models had significant differences. These findings provide further support for the claim that the EDM and the Decision Model (DM) mechanisms provide unique and accurate descriptions of the molecular processes governing choice behaviour. Moreover, the implication from these results is that the underlying assumption of the EDM and DM – that choice is determined by the propensity to respond rather than conditioned reinforcement – appears to have further foundation. This challenges the assumptions of existing models of choice behaviour and presents the possibility that probabilistic approaches are perhaps more appropriate for describing response allocations than discrete estimates of relative value when contingencies change.

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  • Understanding and Improving Navigation Within Electronic Documents

    Alexander, Jason (2009)

    Doctoral thesis
    University of Canterbury Library

    Electronic documents form an integral part of the modern computer age---virtually all personal computers have the ability to create, store and display their content. A connection to the Internet provides users with an almost endless source of documents, be they web-pages, word-processor files or emails. However, the entire contents of an electronic document are often too large to be usefully presented on a user’s screen, at a single point in time. This issue is usually overcome by placing the content inside a scrolling environment. The view onto the document is then modified by directly adjusting a scrollbar or by employing tools such as the mousewheel or paging keys. Applications may also provide methods for adjusting the document’s zoom and page layout. The scrollbar has seen widespread adoption, becoming the default tool used to visualise large information spaces. Despite its extensive deployment, researchers have little knowledge on how this and related navigation tools are used in an everyday work environment. A characterisation of users’ actions would allow designers to identify common behaviours and areas of inefficiency as they strive to improve navigation techniques. To fill this knowledge gap, this thesis aims to understand and improve navigation within desktop-based electronic documents. This goal is achieved using a five step process. First, the literature is used to explore document navigation tasks and the tools currently available to support electronic document navigation. Second, a software tool called AppMonitor, that logs users’ navigation actions, was developed. Third, AppMonitor was deployed in a longitudinal study to characterise document navigation actions in Microsoft Word and Adobe Reader. Forth, to compliment this study, two task-centric observations of electronic document navigation were performed, to probe the reasons for navigation tool selection. Finally, the Footprints Scrollbar was developed to improve one common aspect of navigation—within-document revisitation. To begin, two areas of current knowledge in this domain are overviewed: paper and electronic document navigation and electronic document navigation tools. The literature review produced five categories of document navigation tasks: ‘overviewing and browsing’, ‘reading’, ‘annotating and writing’, ‘searching’ and ‘revisitation’. In a similar fashion, electronic document navigation tools were reviewed and divided into eight categories: core navigation tools (those commonly found in today’s navigation systems), input devices, scrollbar augmentations, content-aware navigation aids, visualisations that provide multiple document views, indirect manipulation techniques, zooming tools and revisitation tools. The literature lacked evidence of an understanding of how these current document navigation tools are used. To aid the gathering of empirical data on tool use, the AppMonitor tool was developed. It records user actions in unmodified Windows applications—specifically for this research, Microsoft Word and Adobe Reader. It logs low-level interactions such as “left mouse button pressed” and “Ctrl-f pressed” as well as high level ‘logical’ actions such as menu selections and scrollbar manipulations. It requires no user input to perform these tasks, allowing study participants to continue with their everyday work. To collect data to form a characterisation of document navigation actions, 14 participants installed AppMonitor on their computer for 120 days. This study found that users primarily employ the mousewheel, scrollbar thumb and paging keys for navigation. Further, many advanced navigation tools that are lauded for their efficiency, including bookmarks and search tools, are rarely used. The longitudinal study provided valuable insights into the use of navigation tools. To understand the reasons behind this tool use, two task-centric observations of electronic document navigation were conducted. The first asked participants to perform a series of specific navigation tasks while AppMonitor logged their actions. The second was performed as a series of interactive sessions, where users performed a particular task and were then probed on their tool choice. These two studies found that many users are not aware of the advanced navigation tools that could significantly improve their navigation efficiency. Finally, the characterisations highlighted within-document revisitation as a commonly performed task, with current tools that support this action rarely used. To address this problem, the analysis, design and evaluation of a Footprints Scrollbar is presented. It places marks inside the scrollbar trough and provides shortcuts to aid users return to previously visited locations. The Footprints Scrollbar was significantly faster and subjectively preferred over a standard scrollbar for revisitation tasks. To summarise, this thesis contributes a literature review of document navigation and electronic document navigation tools; the design and implementation of AppMonitor—a tool to monitor user actions in unmodified Windows applications; a longitudinal study describing the navigation actions users perform; two taskcentric studies examining why actions are performed; and the Footprints Scrollbar, a tool to aid within-document revisitation tasks.

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  • Mafic-felsic interaction in a high level magma chamber - the Halfmoon Pluton, Stewart Island, New Zealand: implications for understanding arc magmatism

    Turnbull, Rose Elizabeth (2009)

    Doctoral thesis
    University of Canterbury Library

    Field evidence from exposed plutonic rocks indicates that mafic-felsic magma interaction is an important process during the construction and evolution of magma chambers. The exhumed, ~140 Ma, Halfmoon Pluton of Stewart Island, New Zealand is characterized by a sequence of mingled mafic sheets and enclaves preserved within an intermediate-felsic host, and provides a unique opportunity to directly investigate the physico-chemical processes that operate within an arc setting. Interpretation of mingling structures and textures in the field, in combination with extensive petrographic, geochemical and geochronological data, allow for conclusions to be reached regarding the nature of the mafic-felsic magma interactions, and the physical, chemical and thermal processes responsible for the generation and evolution of the calc-alkaline magmas. Detailed documentation and interpretation of mafic-felsic magma mingling structures and textures reveal that the Halfmoon Pluton formed incrementally as the result of episodic replenishments of mafic magma emplaced onto the floor of an aggrading intermediate-felsic magma chamber. Physico-chemical processes identified include fractional crystallization and accumulation of a plagioclase – hornblende – apatite – zircon mineral assemblage, episodic replenishment by hot, wet basaltic magmas, magmatic flow and compaction. Early amphibole and apatite crystallization played an important role in the compositional diversity within the Halfmoon Pluton. Variations in the style of magma mingling preserved within the magmatic “stratigraphy” indicate that processes operating within the chamber varied in space and time. Variations in mineral zoning and composition within hornblende indicate that the Halfmoon Pluton crystallized within a magma in which melt composition fluctuated in response to repeated mafic magma replenishments, fractionation, crystal settling and convection. Mineral assemblages, chemical characteristics, isotopic data and geochronological evidence indicate that the amphibole-rich calc-alkaline Halfmoon Pluton was emplaced into a juvenile arc setting, most probably an island-arc. Data are consistent with a model whereby ‘wet’ amphibole-rich basaltic magmas pond at the crust-mantle interface and episodically rise, inject and mingle with an overlying intermediate-felsic magma chamber that itself represents the fractionated product of the mantle melts.

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  • Russian Ethnocentrism and the West: Cultural and Historical Dynamics of Perception of the West in Russia.

    Derbisheva-Sutherland, Onola (2009)

    Doctoral thesis
    University of Canterbury Library

    Opposition to the West is one of the stable characteristics of the Russian history. It is not only enshrined in the mentality of Russian people, but has become an integral part of the social and political culture of the country. The crisis facing Russia at the present time, the active modernisation and inclusion in the globalisation not only further exacerbate this confrontation, but also actualise the perennial alternative facing Russia: to converge with the West, or enter a new confrontation with it. This study explores the influence of the ethnocentric dimension on the cultural and historical dynamics of the paradigm 'Russia vs the West'. The new concept of content, structure, forms and levels of the ethnocentrism phenomenon developed by the author is tested on the basis of integrated analysis of cultural and historical evolution of Russia, the exploration of interaction between the processes of modernisation and the peculiarities of the perception of its 'modernisation standard' – the West. The data employed by the author comes from sociological studies conducted in the last 20 years and enables not only to identify the major determinants and factors influencing the current strategy of relations between Russia and the West, but also to predict the possible scenario of the development of processes of post-Soviet modernisation of this country and its interaction with the outside world.

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  • The European Union in the Asia-Pacific: Current Representations and the Potential Impact of the EEAS.

    Kelly, Serena Lee (2009)

    Doctoral thesis
    University of Canterbury Library

    The European Union (EU) has been called an experiment in a world system traditionally dominated by nation states and the use of military coercion. Because of its uniqueness, academics have sought new theories in order to understand it. This thesis draws on two of these theories in order to gain an understanding about the driving force behind the proposed European External Action Service (EEAS); the socalled ‘expectations-capabilities gap’ and Normative Power Europe (NPE). The former is agency-centred and draws on understandings about the capability of the EU as an international actor and the impact of both internal and external expectations placed on it, that it does not necessarily have the means to live up to. The latter theory –NPE- is identity centred, and concerns how the EU is understood with a focus on norms and values which it wishes to export to the rest of the world. One of the connecting themes of the two theories is a stress on the need to have effective communication. Using both a qualitative and quantitative methodology, this thesis aims to understand how the EU is currently represented in the Asia-Pacific and the potential of the EEAS to improve this representation. Ultimately, there are three findings for this thesis. Firstly, how the EU sees itself and its role in the world does not necessarily correlate with outsiders’ perceptions of it. Secondly, part of the confusion and ineffectiveness of the EU to be recognised could be directly related to its confusing multirepresentation in third countries. Finally, the EEAS has the ability to greatly improve the way the EU operates and communicates, thus potentially narrowing the ‘expectations-capabilities gap’ as well as improving the capability of the EU to be a normative power. However, the vagueness of the EEAS proposals means that steps must be taken to ensure that the EEAS is supported by the other EU actors who will be affected by the new system, as well as ensuring that the proposals are effective in carrying out the goals that it has set out to achieve. This is important if the EU aims to be taken more seriously as an international actor and is to be a force for good in the world. However, caution must be taken against building up the expectations placed on the EEAS too much – history demonstrates that it would be foolish to market the EEAS as a panacea for all of the EU’s problems.

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  • Sri Lankan, Low-Country, Ritual Drumming: The Raigama Tradition

    Suraweera, Sumuditha (2009)

    Doctoral thesis
    University of Canterbury Library

    This thesis provides an in-depth account of the Low-Country, ritual, drumming tradition of Sri Lanka. Low-Country drumming is characterized by its expressive and illusive sense of timing which makes it appear to be free of beat, pulse and metre. This makes it special in respect to other drumming cultures of the world. However, the drumming of the Low-Country is marginalized, unaccepted and unexposed. Drawing on original fieldwork from the Western province of Sri Lanka, this study analyses the drumming of three distinct rituals: devol maḍuva, Kalu Kumāra samayama and graha pūjāva of Raigama, the dominant sub-tradition of the Low-Country. The thesis reveals key features of the drumming tradition, some of which are hidden. These features include the musical structure that is beneath the surface of the drumming, timing, embellishment, improvisation and performance practice. It also documents the Low-Country drum, the yak beraya, its construction and relationship to the musician. The thesis addresses some of the changes that are occurring in the contemporary ritual and argues the need for the drumming to be brought out of its ritual context, for its survival in the future. It also documents a collaborative performance between Low-Country ritual performers and musicians from New Zealand.

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  • Vulnerability of Pastoral Farming Systems to Volcanic Ashfall Hazards

    Wilson, Thomas McDonald (2009)

    Doctoral thesis
    University of Canterbury Library

    Volcanic eruptions are powerful, spectacular, uncontrollable geophysical events which require management to mitigate loss of life and property. An essential part of volcanic risk management is to quantify the vulnerability of exposed elements of society to volcanic hazard. Agriculture takes advantage of the fertile soils of volcanic regions, but is vulnerable to damage and disruption from volcanic hazards, in particular ashfall. This thesis investigates the vulnerability of pastoral agriculture to volcanic ashfall by examining impacts on the resource base of pastoral farming (water supply, pasture and soil, and livestock) and explores mitigation and recovery strategies for ashfall hazards at varying levels. It provides a quantitative understanding of pastoral farming vulnerability to ashfall hazards, as part of probabilistic risk assessment. Surface farm water supplies are found to be more vulnerable to ashfall, through contamination and sedimentation, than groundwater supplies. After heavy ashfall, the physical impacts of ashfall overwhelm the more subtle chemical impacts on water supply systems, but even relatively thin ashfalls may cause potential toxic changes to water quality. Farm-scale assessment of water supplies was used to identify key areas of vulnerability to ash hazards. Modelling a large-scale evacuation of livestock following widespread, heavy ashfall found the logistical, time and cost requirements high and may make this action unrealistic. Perhaps most critically, it is doubtful that farms in surrounding regions have the capacity to accommodate the numbers of animals likely to be affected. Tunnel-house and field trials have shown pastures are relatively resilient to ashfalls of 10 mm, but this resilience rapidly reduces with increasing ashfall thickness and at .100 mm there is effectively no pasture recovery. Ashfall grain size, frequency, soluble salt volume, and different meteorological conditions also have a significant impact on pastures and soils. Pasture reestablishment will benefit from tillage of ash covered soils to mix ash and topsoil and break up the surface crust which may form on ash deposits. Targeted fertiliser treatments may also be required to buffer acidic soluble salts and remedy deficiencies of essential nutrients. Reworking of ash deposits was found to be highly disruptive to pasture re-establishment and in extreme cases may prolong and intensify the impacts following an ashfall. The majority of farmers impacted by ashfall will continue farming, albeit with varying levels of disruption. However real or perceived impacts to human health may result in farm evacuation in the short-term. Where ashfall thicknesses are too thick for a return to profitable farming, migration from impacted farms and agriculture-related industries will result in significant demographic changes to rural communities and potential social impacts. Stressed farming systems are most vulnerable to failure and psychosocial impacts.

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  • Effects of Cyclodextrins on the Kinetics of Emulsion Polymerisation

    El-Hadad, Omar (2009)

    Doctoral thesis
    University of Canterbury Library

    Cyclodextrins (CD) are semi-natural oligosaccharides composed of a number of D-glucose units. They are produced from renewable resources, and have been found to be of catalytic effect for the emulsion polymerization of many monomers. Using monomers whose emulsion polymerization kinetics have been thoroughly studied, this research analyses the effect of CD on the entry and exit rate coefficients for the emulsion polymerization of styrene, and the entry and termination rate coefficients for the emulsion polymerization of MMA. Throughout the course of the work, CD was found to have a positive impact on the polymerization rate of styrene in a polystyrene latex stabilized with a cationic surfactant. Furthermore, the exit rate coefficient for this latex was found, via γ-relaxation experiments, to increase in proportion to the styrene solubility in water, exactly as predicted by theory. Of itself this would lead to a decrease in reaction rate. That there is still an overall increase in the reaction rate in the presence of CD is because of a quite strong effect on entry rate coefficients. Again, this is consistent with the prevailing theory for entry, that of Maxwell and Morrison, which says that increased aqueous phase solubility of monomer will lead to faster entry. Intriguingly, experiments done on a polystyrene latex stabilized with an anionic surfactant showed a different effect for CD: γ-relaxation experiments found very little effect of CD on exit rate, and chemically initiated experiments found the same for overall rate. This is consistent with CD having little effect on aqueous phase styrene solubility, which in fact is what direct measurements via UV-visible spectroscopy indicated. It is speculated that the anionic surfactant was successfully competing with styrene to occupy the CD cavities. On the other hand, measurements suggested that styrene successfully competes with cationic surfactant, which is consistent with kinetic results. Experiments of the above nature were then carried out with methyl methacrylate (MMA), a more water soluble monomer than styrene and one with emulsion polymerisation kinetics of a different nature (so-called pseudo-bulk). γ-relaxation experiments found no effect of CD on termination rate coefficients, exactly as one would expect given that termination is an intra-particle reaction whereas CD exists in the aqueous phase. However the same experiments also revealed an unexpected effect of CD on entry: the thermal entry rate coefficient was found to increase markedly in the presence of CD. It seems likely that this unusual effect stems from interaction of products of γ radiolysis with CD. Results for chemically-initiated polymerization of MMA were inconclusive. Under some conditions there was actually retardation in the presence of CD, which is actually consistent with measurements of MMA solubility in water, which suggested a slightly negative effect of CD. However it is hard to explain such a phenomenon. Further, under other conditions it was found that CD either had no effect on chemically-initiated rate or could even increase it slightly. The only safe conclusion at this stage is that CD has no major effect on MMA kinetics, which arguably is consistent with MMA being relatively water soluble: intuitively one would expect that CD is most useful (‘catalytic’) for the EP of monomers of low solubility.

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  • OPIRA: The Optical-flow Perspective Invariant Registration Augmentation and other improvements for Natural Feature Registration

    Clark, Adrian James (2009)

    Doctoral thesis
    University of Canterbury Library

    In the domain of computer vision, registration is the process of calculating the transformation between a known object, called a marker, and a camera which is viewing it. Registration is the foundation for a number of applications across a range of disciplines such as augmented reality, medical imaging and robotic navigation. In the set of two dimensional planar markers, there are two classes: (1) fiducial, which are designed to be easily recognisable by computers but have little to no semantic meaning to people, and (2) natural features, which have meaning to people, but can still be registered by a computer. As computers become more powerful, natural feature markers are increasingly the more popular choice; however there are still a number of inherent problems with this class of markers. This thesis examines the most common shortcomings of natural feature markers, and proposes and evaluates solutions to these weaknesses. The work starts with a review of the existing planar registration approaches, both fiducial and natural features, with a focus on the strengths and weaknesses of each. From this review, the theory behind planar registration is discussed, from the different coordinate systems and transformations, to the computation of the registration transformation. With a foundation of planar registration, natural feature registration is decomposed into its main stages, and each stage is described in detail. This leads into a discussion of the complete natural feature registration pipeline, highlighting common issues encountered at each step, and discussing the possible solutions for each issue. A new implementation of natural feature registration called the Optical-flow Perspective Invariant Registration Augmentation (OPIRA) is proposed, which provides vast improvements in robustness to perspective, rotation and changes in scale to popular registration algorithms such as SIFT, SURF, and the Ferns classifier. OPIRA is shown to improve perspective invariance on average by 15% for SIFT, 25% for SURF and 20% for the Ferns Classifier, as well as provide complete rotation invariance for the rotation dependent implementations of these algorithms. From the investigation into problems and potential resolutions at each stage during registration, each proposed solution is evaluated empirically against an external ground truth. The results are discussed and a conclusion on the improvements gained by each proposed solution and the feasibility of use in a real natural feature registration application is drawn. Finally, some applications which use the research contained within this thesis are described, as well as some future directions for the research.

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  • Social Competence at Age 4 Years, of Children Born Very Preterm

    Hood, Kelly Marie (2009)

    Doctoral thesis
    University of Canterbury Library

    Very preterm birth is an important developmental and public health concern, with clear evidence to suggest that very preterm children may be at long term risk of neurodevelopmental impairment and educational difficulties. Although a great deal is known about the neurodevelopmental outcomes associated with very preterm birth,comparatively little is known about the social competence of children born very preterm during the important early childhood period. Therefore, as part of a prospective, longitudinal study, this research examined the social competence of 105 children born very preterm (birth weight s abilities to regulate their emotions and behaviour represent important building blocks for their later social and emotional functioning. Further, these abilities will likely influence the extent to which children are able to successfully transition to school. Therefore,alongside other important aspects of development, these findings highlight the importance of monitoring the social abilities of preschoolers who were born very preterm across a range of developmental domains and contexts. Preschoolers characterised by emotional, behavioural and/or interpersonal difficulties could then receive targeted intervention aimed at facilitating their social competence prior to school entry.

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  • Novel Mathematical Aspects of Phylogenetic Estimation

    Fischer, Mareike (2009)

    Doctoral thesis
    University of Canterbury Library

    In evolutionary biology, genetic sequences carry with them a trace of the underlying tree that describes their evolution from a common ancestral sequence. Inferring this underlying tree is challenging. We investigate some curious cases in which different methods like Maximum Parsimony, Maximum Likelihood and distance-based methods lead to different trees. Moreover, we state that in some cases, ancestral sequences can be more reliably reconstructed when some of the leaves of the tree are ignored - even if these leaves are close to the root. While all these findings show problems inherent to either the assumed model or the applied method, sometimes an inaccurate tree reconstruction is simply due to insufficient data. This is particularly problematic when a rapid divergence event occurred in the distant past. We analyze an idealized form of this problem and determine a tight lower bound on the growth rate for the sequence length required to resolve the tree (independent of any particular branch length). Finally, we investigate the problem of intermediates in the fossil record. The extent of ‘gaps’ (missing transitional stages) has been used to argue against gradual evolution from a common ancestor. We take an analytical approach and demonstrate why, under certain sampling conditions, we may not expect intermediates to be found.

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  • Entomopathogenic fungi in New Zealand native forests : the genera Beauveria and Isaria

    Cummings, Nicholas John (2009)

    Doctoral thesis
    University of Canterbury Library

    Species of the entomopathogenic fungal genera Beauveria and Isaria were collected and isolated from diverse arthropod hosts in native forests. Morphological observations and analysis of DNA sequence data from three nuclear gene regions were used to identify taxa and examine phylogenetic relationships. Several new host associations were found for Beauveria species. The recently described species Beauveria malawiensis is reported infecting insects in New Zealand for the first time. The known host range of this species is extended to include Hemiptera, Hymenoptera, Orthoptera and Phasmatodea. Beauveria caledonica, previously only recorded in New Zealand from introduced bark beetles in pine forests, is reported for the first time in native forests and on non-coleopteran hosts. Insect bioassays of Beauveria bassiana and B. malawiensis isolates were conducted to examine host specificity and identify strains with potential for controlling introduced Vespula wasps. Bioassay results generally suggested that strains did not have specific host requirements and isolates of both species were found to be pathogenic towards Vespula larvae. Morphological and molecular data indicated that two distinct groups of Isaria farinosa-like fungi occur in New Zealand and should be recognised as separate species. Similarly, two discrete groups resembling Isaria cicadae were identified. The results indicate that species diversity in Isaria has been previously underestimated in New Zealand.

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  • Experimental Studies of Ion-Neutral Chemistry Related to the Extraterrestrial Environment

    Edwards, Samuel Joseph (2009)

    Doctoral thesis
    University of Canterbury Library

    Kinetic data is presented for a variety of ion-neutral reactions which are relevant to the atmosphere of Titan and to the chemistry occurring in interstellar clouds. The data were recorded with a Selected Ion Flow Tube (SIFT) operating at room temperature (294 ± 4 K) and at a pressure of 0.46 Torr. Results of the recent Cassini-Huygens mission to Saturn and Titan have identified several species in the atmosphere of Titan not predicted by pre-Cassini models of the atmosphere. In order to determine the fate of three of these species (methylenimine, propionitrile and cyanodiacetylene) in Titan's ionosphere, their reactivity with the principal ions in Titan's upper ionosphere has been examined. As expected, collision rate proton transfer reactions dominate the chemistry with association channels also observed with many of the hydrocarbon ions. The results of the Cassini mission also identified several individual reactions as being of potential importance to models of Titan's atmosphere and this chemistry has also been examined. The above studies are also relevant to the interstellar medium where each of the neutral reactants have also been detected. The results of some proton transfer equilibrium studies are also presented. The gas phase basicities of propyne and acetylene have been determined to be 681 kJ mol⁻¹ and 617.4 kJ mol⁻¹ respectively. Their relative proton affinities can be estimated from these values. A combined experimental/theoretical study of the proton affinity of cyanodiacetylene (HC₅N) has enabled this value to be estimated at 770 ± 20 kJ mol⁻¹. Details of an attempt to complete the first laboratory measurement of the crucial reaction between H₃⁺ and atomic carbon are presented. The generation of atomic carbon in sufficient quantities for reaction in the SIFT was not possible with the microwave discharge source used. Other generation methods have also been explored with the laser photolysis of carbon suboxide expected to provide a possible solution to the problems encountered. The results of an investigation into the applicability of lithium ions (Li⁺) to SIFT-MS are presented. The lithium ions associated with each of the twenty-one neutral analytes examined to form pseudo-molecular ions. The association reactions were rapid (k ~ 10⁻⁹ cm³ s⁻¹) for large hydrocarbons but were much slower for smaller analytes (k < 10⁻¹¹ cm³ s⁻¹). In order to clarify some unusual experimental observations, the effect of water molecules on the observed chemistry has been examined in detail. The measured chemistry has important consequences for the applicability of Li⁺ to SIFT-MS where the presence and detection of an identifiable ion of the analyte is essential. Details of new SIFT operating software which can be run on a modern computer are given. Mass spectra and kinetic data recorded with the new software are also presented.

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  • The political philosophy of property rights

    MacDonald, Lindsey Te Ata o Tu (2009)

    Doctoral thesis
    University of Canterbury Library

    This thesis argues that within political philosophy, property rights deserve closer attention than has been paid to them recently because the legitimacy of a state rests upon their definition and enforcement. In this way property rights differ from the right to liberty or equality. A state may or may not have liberty or equality, but it has no meaning at all if it does not enforce the rights of property. This is not to suggest that normative arguments for property rights are ‘nonsense upon stilts’. Morality may provide many reasons for an individual to exclude other members of a political community from a property. However, the function of property rights is to enforce that exclusion and this suggests that the normative legitimacy of a state is closely bound both to its ability to enforce whatever property rights it already has granted, and its justification of decisions taken when property rights are granted within its borders. My argument is that a proper political philosophy of property rights should acknowledge that a state depends upon its treatment of property rights for justification, not as a matter of justice, but as a matter of its existence.

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  • Speech, Phonological Awareness and Literacy in New Zealand Children with Down Syndrome

    van Bysterveldt, Anne Katherine (2009)

    Doctoral thesis
    University of Canterbury Library

    Children with Down syndrome (DS) are reported to experience difficulty with spoken and written language which can persist through the lifespan. However, little is known about the spoken and written language profiles of children with DS in the New Zealand social and education environment, and a thorough investigation of these profiles has yet to be conducted. The few controlled interventions to remediate language deficits in children with DS that are reported in the literature typically focus on remediation of a single language domain, with the effectiveness of interventions which integrate spoken and written language goals yet to be explored for this population. The experiments reported in this thesis aim to address these areas of need. The following questions are asked 1) What are the phonological awareness, speech, language and literacy skills of New Zealand children with DS? 2) What are the home and school literacy environments of New Zealand children with DS and how do they support written language development? and 3) What are the immediate and longer term effects of an integrated phonological awareness intervention on enhancing aspects of spoken and written language development in young children with DS? These questions will be addressed through the following chapters. The first experiment (presented in Chapter 2) was conducted in two parts. Part 1 consisted of the screening of the early developing phonological awareness, letter knowledge, and decoding skills of 77 primary school children with DS and revealed considerable variability between participants on all measures. Although some children were able to demonstrate mastery of the phoneme identity and letter knowledge skills, floor effects were also apparent. Data were analysed by age group (5 - 8 years and 9 -14 years) which revealed increased performance with maturation, with older children outperforming their younger peers on all measures. Approximately one quarter of all children were unable to decode any words, 6.6% demonstrated decoding skills at a level expected for 7 - 8 year old children and one child demonstrated decoding skills at an age equivalent level. Significant relationships between decoding skills and letter knowledge were found to exist. In Part 2 of the experiment, 27 children with DS who participated in the screening study took part in an in-depth investigation into their speech, phonological awareness, reading accuracy and comprehension and narrative language skills. Results of the speech assessments revealed the participants’ speech was qualitatively and quantitatively similar to the speech of younger children with typical development, but that elements of disorder were also evident. Results of the phonological awareness measures indicated participants were more successful with blending than with segmentation at both sentence and syllable level. Rhyme generation scores were particularly low. Reading accuracy scores were in advance of reading comprehension, with strong relationships demonstrated between reading accuracy and phonological awareness and letter knowledge. Those children who were better readers also had better language skills, producing longer sentences and using a greater number of different words in their narratives. The production of more advanced narrative structures was restricted to better readers. In the second experiment (presented in Chapter 3), the home literacy environment of 85 primary school aged children with DS was investigated. Parents of participants completed a questionnaire which explored the frequency and duration of literacy interactions, other ways parents support and facilitate literacy, parents’ priorities for their children at school, and the child’s literacy skills. Results revealed that the homes of participants were generally rich in literacy resources, and that parents and children read together regularly, although many children were reported to take a passive role duding joint story reading. Many parents also reported actively teaching their child letter names and sounds and encouraging literacy development in other ways such as language games, computer use, television viewing and library access. Writing at home was much less frequent than reading, and the allocation of written homework was much less common than reading homework. In the third experiment (presented in Chapter 4), the school literacy environment of 87 primary school aged children with DS (identified in the second experiment) was explored. In a parallel survey to the one described in Chapter 3, the teachers of participants completed a questionnaire which explored the frequency and duration of literacy interactions, the role of the child during literacy interactions, the child’s literacy skills, and other ways literacy is supported. The results of the questionnaire revealed nearly all children took part in regular reading instruction in the classroom although the amount of time reportedly dedicated to reading instruction was extremely variable amongst respondents. The average amount of time spent on reading instruction was consistent with that reported nationally and in advance of the international average for Year 5 children. Reading instruction was typically given in small groups or in a one on one setting and included both ‘top-down’ and bottom up’ strategies. Children were more likely to be assigned reading homework compared to written homework, with writing activities and instruction reported to be particularly challenging. In the fourth experiment (reported in Chapter 5), the effectiveness of an experimental integrated phonological awareness intervention was evaluated for ten children with DS, who ranged in age from 4;04 to 5;05 (M = 4;11, SD = 4.08 months). The study employed a multiple single-subject design to evaluate the effect of the intervention on participants’ trained and untrained speech measures, and examined the development of letter knowledge and phonological awareness skills. The 18 week intervention included the following three components; 1. parent implemented print referencing during joint story reading, 2. speech goals integrated with letter knowledge and phoneme awareness activities conducted by the speech-language therapist (SLT) in a play based format, and 3. letter knowledge and phoneme awareness activities conducted by the computer specialist (CS) adapted for presentation on a computer. The intervention was implemented by the SLT and CS at an early intervention centre during two 20 minute sessions per week, in two 6 week therapy blocks separated by a 6 week break (i.e. 8 hours total). The parents implemented the print referencing component in four 10 minute sessions per week across the 18 week intervention period (approximately 12 hours total). Results of the intervention revealed all ten children made statistically significant gains on their trained and untrained speech targets with some children demonstrating transfer to other phonemes in the same sound class. Six children demonstrated gains in letter knowledge and nine children achieved higher scores on phonological awareness measures at post-intervention, however all phonological awareness scores were below chance. The findings demonstrated that dedicating some intervention time to facilitating the participants’ letter knowledge and phonological awareness was not at the expense of speech gains. The fifth experiment (presented in Chapter 6) comprises a re-evaluation of the speech, phonological awareness, and letter knowledge, and an evaluation of the decoding and spelling development in children with DS who had previously participated in an integrated phonological awareness intervention (see Chapter 5), after they had subsequently received two terms (approximately 20 weeks) of formal schooling. Speech accuracy was higher at follow-up than at post-intervention on standardised speech measures and individual speech targets for the group as a whole, with eight of the ten participants demonstrating increased scores on their individual speech targets. Group scores on both letter knowledge measures were higher at follow-up than at post-intervention, with nine participants maintaining or improving on post-intervention performance. The majority of participants exhibited higher phonological awareness scores at follow-up on both the phoneme level assessments, with above chance scores achieved by five participants on one of the tasks, however, scores on the rhyme matching task demonstrated no evidence of growth. Some transfer of phonological awareness and letter knowledge was evident, with five children able to decode some words on the single word reading test and three children able to represent phonemes correctly in the experimental spelling task. The emergence of these early literacy skills highlighted the need for ongoing monitoring of children’s ability to transfer their improved phonological awareness and letter knowledge to decoding and spelling performance. In the sixth experiment (presented in Chapter 7) the long term effects of the integrated phonological awareness intervention was evaluated for one boy with DS aged 5;2 at the start of the intervention. The study monitored Ben’s speech and literacy development up to the age of 8;0 (34 months post pre-school intervention) which included two years of formal schooling. Ben demonstrated sustained growth on all measures with evidence of a growing ability to transfer letter-sound knowledge and phoneme-grapheme correspondences to the reading and spelling process. The results indicated an intervention which is provided early and which simultaneously targets speech, letter knowledge and phonological awareness goals provides a promising alternative to conventional therapy, and that integrating spoken and written therapy goals for children with DS can be effective in facilitating development in both domains. This thesis provides evidence that the spoken and written language abilities of New Zealand children with DS exhibit a pattern of delay and disorder that is largely consistent with those of children with DS from other countries reported in the literature. The home and school literacy environments of children in New Zealand with DS are rich in literacy resources and are, for the most part, supportive of their literacy development. The immediate and longer term results of the integrated phonological awareness intervention suggest that it is possible to achieve significant and sustained gains in speech, letter knowledge and phonological awareness which may contribute to the remediation of the persistent and compromised spoken and written language profile characteristic of individuals with DS.

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  • Bombay Scarcity-Relief Policies in the Age of Reform, 1820-40

    Campbell, Charles P. (2009)

    Doctoral thesis
    University of Canterbury Library

    This thesis examines the influence of certain British reformist ideologies on the scarcity-relief policies of the British colonial Government of Bombay from 1820 to 1840. It outlines the laissez-faire and utilitarian ideologies of relevance to scarcity-relief and assesses the extent to which these ideologies influenced Bombay’s policies toward the grain trade, charity, public works, agricultural loans, land revenue, and grain duties, during the 1823-5, 1831-5, and 1838-9 droughts. The thesis demonstrates that ideological debate and policy formation engaged officials at various levels within the colonial administration, and was not simply the concern of the Bombay Council. The thesis argues that while reformist ideologies had a genuine effect on the stated beliefs of many of Bombay’s officials, fiscal expediency and, to a lesser extent, humanitarian concern, also contributed to the formation of Bombay policy. It contends that these other factors were sometimes in harmony, and other times at odds, with the new ideologies coming from Britain. It finds that each of Bombay’s scarcity-relief policies was shaped by reformist ideology, but to a varying degree, and at different times, depending on the resistance to changes in policy from conservatives within the administration. This resistance, it argues, was in turn determined by the extent to which officials perceived each policy to be a foundation of the Government’s financial well-being. The findings of this thesis support the consensus among most historians of Indian subsistence crises that reformist ideologies of Britain began to influence the scarcity-relief policies of British Indian administrations in the early nineteenth century.

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