455 results for Doctoral, 2007

  • The cultural transmission of cookery knowledge : from seventeenth century Britain to twentieth century New Zealand

    Inglis, Raelene (2007)

    Doctoral thesis
    University of Otago

    xv, 354 leaves :ill., map ; 30 cm. Includes bibliographical references. University of Otago department: Anthropology.

    View record details
  • Testing Protocol Development for a Proton Exchange Membrane Fuel Cell

    Page, Shannon Charles (2007)

    Doctoral thesis
    University of Canterbury Library

    Fuel cell technology has undergone significant development in the past 15 years, spurred in part by its unique energy conversion characteristics; directly converting chemical energy to electrical energy. As fuel cell technology has past through the prototype/pre-commercialisation development, there is increasing interest in manufacturing and application issues. Of the six different fuel cell types pursued commercially, the Proton Exchange Membrane (PEM) fuel cell has received the greatest amount of research and development investment due to its suitability in a variety of applications. A particular application, to which state-of-the art PEMFC technology is suited, is backup/uninterruptible power supply (UPS) systems, or stand-by power systems. The most important feature of any backup/UPS system is reliability. Traditional backup power systems, such as those utilising valve regulated lead acid (VRLA) batteries, employ remote testing protocols that acquire battery state-of-health and state-of-charge information. This information plays a critical role in system management and reliability assurance. A similar testing protocol developed for a PEM fuel cell would be a valuable contribution to the commercialization of these systems for backup/UPS applications. This thesis presents a novel testing and analysis procedure, specifically designed for a PEM fuel cell in a backup power application. The test procedure electronically probes the fuel cell in the absence of hydrogen. Thus, the fuel cell is in an inactive, or passive, state throughout the testing process. The procedure is referred to as the passive state dynamic behaviour (PSDB) test. Analysis and interpretation of the passive test results is achieved by determining the circuit parameter values of an equivalent circuit model (ECM). A novel ECM of a fuel cell in a passive state is proposed, in which physical properties of the fuel cell are attributed to the circuit model components. Therefore, insight into the physical state of the fuel cell is achieved by determining the values of the circuit model parameters. A method for determining the circuit parameter values of many series connected cells (a stack) using the results from a single stack test is also presented. The PSDB test enables each cell in a fuel cell stack to be tested and analysed using a simple procedure that can be incorporated into a fuel cell system designed for backup power applications. An experimental system for implementing the PSDB test and evaluating the active performance of three different PEM fuel cells was developed. Each fuel cell exhibited the same characteristic voltage transient when subjected to the PSDB test. The proposed ECM was shown to accurately model the observed transient voltage behaviour of a single cell and many series connected cells. An example of how the PSDB test can provide information on the active functionality of a fuel cell is developed. This method consists of establishing baseline performance of the fuel cell in an active state, in conjunction with a PSDB test and identification of model parameter values. A subsequent PSDB test is used to detect changes in the state of the fuel cell that correspond to performance changes when the stack is active. An explicit example is provided, where certain cells in a stack were purposefully humidified. The change in state of the cells was identified by the PSDB test, and the performance change of the effected cells was successfully predicted. The experimental test results verify the theory presented in relation to the PSDB test and equivalent circuit model.

    View record details
  • Uxorial privileges in substantive criminal law: a comparative law enquiry.

    McCoy, Gerard John Xavier (2007)

    Doctoral thesis
    University of Canterbury Library

    This thesis investigates three exemplars of uxorial substantive privileges in the criminal law: the marital coercion doctrine, the intraspousal conspiracy exemption, and the uxorial post-offence accessorial immunity. Their history, choreography and variations are comparatively investigated across the common law jurisdictions including the impact of statutory interventions. The principal argument is that the judicial and legislative treatment of these uxorial privileges has been inconsistent or erratic so that they are not the products of any systematic, modern development in the criminal law. This thesis proposes that there is no justification for their continued retention in common law legal systems. Archival, Parliamentary, and other sources have been used to identify the factors impinging upon the creation of specific statutory uxorial privileges. The diaspora of these laws throughout the other common law jurisdictions is investigated. The discussion is illustrated by examination of the particular issues raised by polygamy, customary law concubinage as well as by gender-reassignment. This thesis examines whether both gender-specific and marriage-specific criteria are valid constituents within the parameters of substantive criminal law. It traces the genesis of these special defences within the criminal law available exclusively to women, from the time of King Ine of the West Saxons c712, to examine the current status of such laws throughout common law jurisdictions. The investigation explores factors shaping the creation of a statutory defence of marital coercion by the British Parliament in 1925 and outlines the challenges generated by that law and its extraordinary resilience. This thesis demonstrates the failure of the criminal law to provide an overarching construct to implement emergent gender equality.

    View record details
  • "Striding both worlds" Cross-Cultural influence in the work of Witi Ihimaera

    Kennedy, Melissa (2007)

    Doctoral thesis
    University of Canterbury Library

    This thesis engages with aspects of Witi Ihimaera's oeuvre that demonstrate influences from cultures other than Maori. These may be overt in the fiction, such as plot settings in Venice, Vietnam and Canada, or implicit in his writing mode and style, influenced by English romanticism, Pakeha cultural nationalism, Katherine Mansfield's modernist epiphanies, and Italian verismo opera. In revealing Ihimaera's indebtedness to cultural and aesthetic influences commonly seen as irrelevant to contemporary Maori literature, this thesis reveals a depth and richness in Ihimaera's imaginary that is frequently overlooked and undervalued in New Zealand literary interpretation. Illuminating cross-cultural influence in Ihimaera's works calls into question the applicability of biculturalism as a comprehensive manner of accounting for both Maori cultural ambitions of self-determination and the Maori relationship with Pakeha on the national level. Far from an "us-versus-them" dialectic based on a separatist notion of two individually self-sufficient and complete cultures, Ihimaera's fiction shows Maori culture to have been shaped by a long history of interaction and influence with the colonial British and the Pakeha. This is manifest in the way that the Maori sovereignty and renaissance movements, which gathered force in the 1970s, have been inspired by European concepts of modernity, the structures of nation building and, more recently, by Western globalization described in the theories of transculturation and diaspora. Similarly, in New Zealand literature, Maori writing is commonly considered a parallel genre which describes a distinctive Maori worldview and literary style. Contrary to the familiar interpretation of Ihimaera's fiction from this standpoint, this thesis argues that an emphasis on difference tends to lose sight of fiction's capacity to bring into play issues of differentiation, originality and hybridity through its very form and function. In effect, Maori negotiation of its sovereign space in its literature takes place in its forms rather than in its storyline, for example in multiple linguistic significations, in the text's unstable relationship with reality, and the way that imagery escapes concrete, definitive explanation. In this optic, this thesis analyses little-discussed aspects of Ihimaera's fiction, including his love of opera, the extravagance of his baroque lyricism, his exploration of the science-fiction genre, and his increasing interest in taking Maori into the international arena. While reading against the grain of current New Zealand literary practice, this thesis does not intend to contest such reading. Rather, it endeavours to present an additional, complementary analytical framework, based on a conviction that contemporary Maori-Pakeha cultural and literary negotiation and contestation is far from unique, but a local manifestation of other international and historical efforts for recognition and respect.

    View record details
  • Design, Synthesis and Characterisation of Inhibitors of 3-Deoxy-D-arabino-Heptulosonate 7-Phosphate Synthase

    Walker, Scott Raymond (2007)

    Doctoral thesis
    University of Canterbury Library

    The enzyme 3-deoxy D-arabino-heptulosonate 7-phosphate (DAH7P) synthase catalyses the first step of the shikimate pathway. This pathway lies at the heart of bacterial metabolism, and is responsible for the synthesis of a variety of compounds essential to the chemistry of life; from the aromatic amino acids phenylalanine, tyrosine and tryptophan, to a number of aromatic and non-aromatic natural products. This thesis describes the design, synthesis and evaluation of inhibitors of DAH7P synthase. These inhibitors exploit a variety of strategies to interrupt the activity of DAH7P synthase, ranging from simple substrate mimicry to inhibitors that mimic unstable reaction intermediates; inhibitors that exploit metal coordination and entropic effects, and inhibitors that gain improved potency by interacting with multiple sites. In Chapter Two, the synthesis of a mimic for a proposed unstable reaction intermediate is described, and its interaction with DAH7P synthase characterised. The compound was prepared in twelve steps from D-arabinose, and was found to be a slow-tight binding inhibitor of Escherichia coli DAH7P synthase. In Chapter Three, a number of compounds are prepared that were designed to bind to the phosphoenolpyruvate subsite of the DAH7P synthase active site. The binding of these compounds to the enzyme is investigated in order to gain an understanding of the factors involved in DAH7P synthase inhibition. The enantiomeric phospholactates were prepared, and the extent of inhibition of E. coli DAH7P synthase was shown to be dependent on compound chirality. Several other phosphoenolpyruvate-like molecules were prepared, and were also shown to be effective DAH7P synthase inhibitors. In Chapter Four extended compounds are designed that will bind the enzyme by multiple interactions at both substrate binding sites. Four compounds were prepared, and an increase in inhibitory potency was observed. In Chapter Five computational techniques are explored to aid the interpretation of the inhibition of DAH7P synthase by the compounds prepared in these studies. Several approaches for more potent inhibition of this enzyme are outlined and discussed.

    View record details
  • Multiwavelength fluorescence studies of Bacillus bacterial spores

    Sarasanandarajah, Sivananthan (2007)

    Doctoral thesis
    University of Canterbury Library

    Fluorescence techniques are being considered for the detection and identification of bacterial spores. This thesis sets out to empirically characterize the detailed autofluorescence spectroscopic properties of spores and their target molecules. The multiwavelength fluorescence studies from a unique endogenous biomarker, dipicolinic acid (DPA) and its calcium salt (CaDPA) in bacterial spores are found to be useful for fluorescence characterization of spores. A systematic determination of the fluorescence profile of the major chemical components of Bacillus spores and the effect of UV irradiation on them has been performed in dry samples, wet paste and in aqueous solution. The thesis applies reliable tools for accurately describing complex nature of spectral profile from bacterial spores, and for interpreting and identifying their spectral properties. We show that multiwavelength fluorescence technique combined with Principal Component Analysis (PCA) clearly indicates identifiable grouping among dry and wet Bacillus spore species. Differences are also observed between dried, wet and redried spores, indicating the stark effect of hydration on fluorescence fingerprints. The study revealed that changes in fluorescence of spores due to hydration/drying were reversible and supports a recent model of a dynamic and dormant spore structure. The spectra were analysed with PCA, revealing several spectroscopically characteristic features enabling spore species separation. The identified spectral features could be attributed to specific spore chemical components by comparing the spore sample signals with spectra obtained from the target molecules. PCA indicated underlying spectral patterns strongly related to species and the derived components were correlated with the chemical composition of the spore samples. More importantly, we examined and compared the fluorescence of normal spores with a mutant of the same strain whose spores lack DPA. We discovered that the dramatic fluorescence enhancement of Bacillus spores can be caused by UV irradiation in the spectral region of this unique biomarker without any pre treatment. Differences between spectra of spores, spore strains and other biological samples are very marked and are due to the dominance of the dipicolinate features in the spore spectra. This could lead to a cheap, more sensitive, faster and reagentless bacterial spore detector.

    View record details
  • Nanostructured Metal Electrodes for Wool Processing and Electroanalysis

    Cruickshank, Amy Clare (2007)

    Doctoral thesis
    University of Canterbury Library

    The research presented in this thesis firstly concerns the use of electrochemical techniques to develop approaches to wool processing which have a lower impact on the environment than conventional chemical methods. Wool is a sulfur rich substrate and current methods used in wool processing often rely on sulfur-based reducing agents such as metabisulfite. However, due to increasing concern over the environmental impacts of metabisulfite, alternative methods are of interest. Electrochemical techniques have been applied to the process of wool setting in the presence of thiol setting agents. Wool disulfide bonds are reduced during this process and the thiol setting agent is converted to the disulfide. Efficient conversion of the disulfide back to the thiol setting agent would allow catalytic amounts of thiols to be used in wool setting. The electroreduction of cystine and 2-hydroxyethyl disulfide has been examined at a range of metal and carbon electrodes to find efficient methods of generating the corresponding thiols, cysteine and 2-mercaptoethanol respectively. Gold and silver were identified as the most efficient electrode materials. In industrial wool processing, the use of large-scale metal electrodes is expensive and therefore, high surface area gold and silver nanoparticle electrodes were fabricated by electrochemically depositing the metals onto low-cost carbon substrates. The most efficient electrochemical system for generating the thiol setting agent involved the electroreduction of cystine at the gold nanoparticle electrode and this system was used to successfully demonstrate that wool setting can be achieved using relatively low concentrations of cysteine. Further research was carried out to investigate methods for the controlled preparation of metal nanoparticle electrodes and their utility for detecting hydrogen peroxide was examined. A simple and versatile approach for the preparation of tethered gold nanoparticle assemblies was developed by exploiting electrostatic interactions between citrate-capped gold nanoparticles and amine tether layers attached to carbon surfaces. The nanoparticle assemblies were optimised for the detection of hydrogen peroxide by selecting the size and density of electrostatically assembled nanoparticles. The number of amine functionalities on the surface and the assembly conditions controlled the nanoparticle density. Nanostructured palladium electrodes fabricated using vapour deposition methods to immobilise palladium nanoparticles directly onto carbon substrates were also examined for the electroanalysis of hydrogen peroxide.

    View record details
  • Modelling and Optimisation of MDF Hot Pressing

    Gupta, Arun (2007)

    Doctoral thesis
    University of Canterbury Library

    There are four big medium density fibreboard (MDF) plants in New Zealand with a total production capacity of close to one million cubic meters per year. A significant quantity of boards (nearly 3% or about 30,000 cubic meters per year) is rejected due to defects such as weak core, low modulus of rupture and elasticity, low internal bonding and delamination. The main cause of these defects, is lack of complete understanding of the inter relationship during the hot-pressing stage between the initial inputs such as temperature, moisture content, platen pressure and its impact on the properties of boards. The best solution is to develop a mathematical model to assist in understanding these relationships and to solve the equations in the model by using advanced software. This will reduce the number of expensive experiments and will enable us to see some of the parameters, which are otherwise difficult to visualise. Several earlier researchers have tried to model hot pressing of wood composites, mostly either for particle board or oriented strand board (OSB), and only a few are for MDF. The type of numerical methods used to solve the model equations and various assumptions, changes from one investigator to the other. The non-availability of source code to convert the mathematical equations into programme, is one of the reasons for this model development. To improve the productivity of MDF plants in New Zealand, there was a need to develop a computer programme which can include all the latest findings and can remove the defects which are present in earlier models. This model attempts a more complete integration than in the previous models of all the components such as heat transfer, moisture movement and vertical density profile formation in a one-dimensional model of hot pressing of MDF. One of the important features added in the heat and mass transfer part of the model is that the equilibrium moisture content (EMC) equation given for solid wood was modified to be applicable for the MDF fibres. In addition, this EMC equation can cover the complete range of hot pressing temperature from 160ºC to 200ºC. The changes in fibre moisture content due to bound water diffusion, which was were earlier neglected, was considered. The resin curing reactions for phenol formaldehyde and urea formaldehyde resins are also incorporated into the model, with the energy and water released during the curing reaction being included in the energy and mass balances. The validation of the heat and mass transfer model was done by comparing the values of core temperature and core pressure from the model and the experiments. The experimental value of core pressure and core temperature is obtained by putting a thermocouple and pressure transducer in the middle of the mat. The experimental core temperature results show qualitative agreement with the predicted results. In the beginning, the core temperatures from both experiment and model overlap each other. In the middle of the press cycle, the experimental core temperature is higher by 10ºC and by the end the difference decreases to 5ºC. The vertical density profile (VDP) is a critical determining factor for the strength and quality of MDF panels. The earlier concept of ratio of modulus of elasticity of the layer to the sum of modulus of elasticity of all the layers in the previous time step, given by Suo and Bowyer (1994), is refined with the latest published findings. The equation given by Carvalho et al. (2001) is used to calculate the MOE of different layers of the mat. The differential equation of a Maxwell element given by Zombori (2001) is used to measure stress, nonlinear strain function and relaxation of fibres. The model gives good agreement of peak and core density at lower platen temperature at 160ºC but with the increase of platen temperature to 198ºC, the rise in peak density is comparatively higher. There is a distinct increase in predicted peak density by 150 kg/m³ in comparison to the experimental result, where the increase is only by 10 kg/m³. There is a large decline (50 kg/m³) in core density in the experimental results in comparison to only a slight decline (13 kg/m³) in the predicted results. The use of Matlab provides a very convenient platform for producing graphical results. The time of computation at present is nearly 20 hrs in a personal computer with Pentium four processor and one GB RAM. The model can predict properties of a pressed board for the standard manufacturing conditions and also the new hot pressing technologies such as the use of steam injection or a cooling zone in the continuous press. A comparative study has been done to show the advantages of using new hot pressing technology. The present model will become an important tool in the hands of wood technologist, process engineers and MDF manufacturing personnel, to better understand the internal processes and to improve production and quality of MDF boards. This theoretical model helped in developing better understanding of internal processes. By using it, we can analyse the impact of platen temperature, moisture content on the core temperature, core pressure and density profile. It gives better insight into the relationship between core pressure and delamination of the board. The model is also able to predict the internal changes in the new hot pressing technologies such as the steam injection pressing and the use of a cooling zone in a continuous press. Using the simulation results, the exact time needed for the complete curing of resin can be calculated and then these results can be applied in the commercial plants. If the pressing time is reduced, then the over all production of both batch press and continuous press will increase. The second part of the project is the development of an empirical model to correlate the physical properties from the MDF board to the mean density. The empirical model is simple and straightforward, and thus can be applied in commercial operation for control and optimization. The empirical model can predict peak density, core density, and modulus of rupture, elasticity and internal bonding within the limits in which those relationships are derived. The model gives good results for thickness ranging from 10 to 13.5 mm and density ranging from 485 kg/m³ to 718 kg/m³.

    View record details
  • An Investigation of the Cognitive and Psychiatric Profile for People with Parkinson's Disease Without Dementia.

    McKinlay, Audrey (2007)

    Doctoral thesis
    University of Canterbury Library

    Introduction: Idiopathic Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder that is characterised by motor symptoms. However, there is increasing awareness that a range of neuropsychiatric and cognitive problems also accompanys PD. The objective of this thesis was to examine the profile of neuropsychiatric and cognitive problems for patients with PD without dementia. Parkinson's disease patients who could be identified at the time of this study were invited to participate. Each patient was individually matched to a healthy control in terms of age, premorbid intelligence, and years of education. Results: Neuropsychiatric symptoms were common for this patient group, over 40% self reported symptoms consistent with depression, 40% with physical fatigue, 38% with mental fatigue, 38% with apathy and 32% with sleep problems. More than 77% of patients with PD reported symptoms associated with at least one problem and over 46% with 3 or more problems. Increased symptoms consistent with depression and anxiety and the presence of hallucinations also predicted poorer quality of life after controlling for motor symptoms. However, the of level agreement between patient report and that of a person who know them well was low: 40.9% for apathy, 28% for hallucinations, 39% for depression, 25% for sleep problems and only 7.7% agreement for the presence of anxiety. To obtain an accurate profile of cognitive impairments patients were assessed on measures of higher order language ability and a broad range of commonly used cognitive tests. Overall, PD patients were impaired on aspects of higher-order language. However, results indicated that these deficits were not a primary effect of PD, but could be explained in terms of deficits in speed of information processing associated with the disease. Compared to healthy controls, PD patients also showed deficits on measures of executive function, working memory, problem solving, and visuospatial skills. However, they were unimpaired on measures of planning, attention and memory/learning. Deficits in problem solving were only evident for tasks with a high visuospatial content and were no longer significant when visuospatial skills were controlled for. Further investigation indicated that planning in PD patients was not impaired in general and was dependent on the sensitivity of tests used. To further examine cognitive deficits, patients were divided into groups according to their cognitive performance. Three sub-groups of patients were identified that formed a continuum of cognitive impairment from none/mild to severe. Compared to controls, one subgroup showed no or minimal impairment (PD-NCI), a second group showed a more variable pattern of severe and mild impairments (PD-UCI), and a third group had evidence of severe impairment across most of the cognitive domains tested. This latter group was labelled PD-Mild Cognitive Impairment (PD-MCI). The PD-UCI and PD-MCI groups were also significantly different from their controls with respect to their ability to carry out functional activities of everyday living. The PD-MCI group had evidence of global cognitive decline, possibly reflecting a stage of pre-clinical dementia. The severity of cognitive deficits was not associated with other clinical and demographic characteristics such as motor impairments, age or disease duration. These results were confirmed when patients were retested one year later. Conclusions: Comorbid neuropsychiatric and cognitive problems are common for patients with PD prior to any overt signs of dementia. However, PD patients are heterogeneous with regard to their presentation and different subgroups of patients are identifiable based on cognitive performance. This information has both theoretical and clinical relevance.

    View record details
  • New Zealand and south-east Australian ilyarachninae (isopoda: asellota: munnopsidae) and their worldwide relationships

    Merrin, Kelly Leeann (2007)

    Doctoral thesis
    University of Canterbury Library

    The diversity of New Zealand and Australian asellote isopods remains largely unknown. Even less is known about how this fauna is related to the rest of the world. This study focuses on the munnopsid subfamily Ilyarachninae Hansen, 1916, to explore the phylogenetic and biogeographic relationships of the local fauna to others from this group worldwide. To analyse the relationships within the Ilyarachninae, a suitable outgroup, in this case, the sister group, was needed to be determined. To do this, a cladistic analysis of the Munnopsidae was undertaken. In addition to determining a suitable outgroup, the family level analysis also served to test the monphyly of the nine subfamilies and to resolve the placement of the three genera, Munneurycope Stephensen, 1913, Munnicope Menzies and George, 1972 and Munnopsurus Richardson, 1912b which were not placed in any exsiting subfamily. The cladistic analysis of the Munnopsidae included 72 species representing all munnopsid genera, including where possible, the type species and was based on 122 morphological characters. A well resolved strict consensus tree was found. The results show Munnopsurus to be the sister group of the Ilyarachninae and the Munnopsinae to be the most ancestral group of the Munnopsidae. Of all the subfamilies, the Betamorphinae is not a monophyletic. The results show that although some subfamily names are upheld, others show no congruence to the topology of the results, and therefore the use of subfamily names are abandoned. Four families are instead recognized, the Munnopsidae (restricted to the former Munnopsinae), Acanthocopidae Wolff, 1962, the Syneurycopidae Wolff, 1962 and the Lipomeridae Tattersall, 1905a, with the latter including the former Ilyarachninae ('Ilyarachna-group'). Within the Ilyarachna-group, two new genera and 28 species were described, including 25 species new to science. Two genera, Notopais and Epikopais n. gen. are found exclusively in the southern hemisphere. Of the more cosmopolitan genera, some New Zealand and south-east Australian species display close affinities to each other and with Antarctic species. These relationships were tested using cladistic phylogenetic methods, and in addition to this, the analysis also served to test the monophyly of the genera. The analysis used 59 species, representing all genera and 61 morphological characters. The strict consensus tree was well resolved, however Aspidarachna Sars, 1897b, Ilyarachna Sars, 1870 and Echinozone Sars, 1897b were not monophyletic. The results also showed that the Ilyarachna-group fauna of New Zealand and south-east Australia are closely related to each other and to species from Antarctica.

    View record details
  • Population bottlenecks and the risk of parasitic and microbiological infections in the endangered saddleback (Philesturnus carunculatus) and South Island robin (Petroica a. australis)

    Hale, Katrina Anne (2007)

    Doctoral thesis
    University of Canterbury Library

    Severe population bottlenecks and the small size of many remnant habitats may render many bird populations prone to extinction from disease outbreaks. Bottlenecks may increase inbreeding which in turn may result in a low diversity of resistance and an immune system that is impaired or defective. Thus, bottlenecked populations may be less immunocompetent and more vulnerable to microbiological and parasitic perturbations. Few studies have assessed the effect of bottlenecks on the immunocompetence of birds. In this study, I used twelve saddleback (Philesturnus carunculatus) and two New Zealand robin (Petroica a. australis) populations, to determine if the severe bottlenecks reduce the immunocompetence of birds. When I experimentally challenged the immune system of two robin populations I found that despite the two populations having similar parasite loads, robins from the severely bottlenecked Motuara Island population exhibited a significantly lower T-cell mediated immune response than the source population (Nukuwaiata Island) suggesting that birds passing through severe population bottlenecks have a compromised immunocompetence. In the saddleback, severe bottlenecks, as well as high population densities and small island size, lead to individuals exhibiting higher stress levels and feather mite loads and lower immune function, as was evident by lower lymphocyte counts. I did not find levels of fluctuating asymmetry of saddlebacks to be directly influenced by bottleneck size. However, I did find that individuals with higher levels of fluctuating asymmetry had higher loads of hippoboscid flies and lower loads of coccidia suggesting a possible trade-off between growth and immune function. In contrast to previous studies looking at behavioural secondary sexual traits, I found no effect of founder number on the size of wattles in saddleback. I did however demonstrate that wattle size reflected the level of immune function in females as well as males, suggesting that females play a far greater role in offspring fitness than has been appreciated in traditional theories of sexual selection. Overall, my results indicate that severe bottlenecks can lead to reductions in immunocompetence in the resulting populations, especially in those populations that pass through the most severe bottlenecks. Based on the evidence from my thesis, I recommend conservation managers should aim to use at least 90 individuals to found new populations in order to reduce the deleterious effects of bottlenecks on immune function. If the costs of population bottlenecks and inbreeding are to be avoided, conservationists must adequately address the role of genetic factors in susceptibility to disease, and work towards minimising the risk of severe population bottlenecks in the management of endangered birds

    View record details
  • A Record of Environmental and Climatic Change from the West Coast, South Island, New Zealand, using Beetle Fossils

    Burge, Philip Ian (2007)

    Doctoral thesis
    University of Canterbury Library

    Fossil beetle based palaeoclimatic and palaeoenvironmental reconstructions are presented from the Westport region, West Coast, South Island, New Zealand for the last glacial cycle. They include the longest continuous fossil beetle record from New Zealand, covering 16,000 years over the OIS 3/OIS 2 transition. Early last glacial (OIS 4) and mid- Holocene (OIS 1) reconstructions are also presented. The assumptions underlying fossil beetle research in New Zealand are tested indicating beetles are suitable proxies for reconstructing palaeotemperature and palaeoprecipitation. This thesis provides the first quantitative estimates of temperature and precipitation from the Westport region for the last glacial. Reconstructed temperatures indicate stadial cooling was seasonal. Maximum cooling was ca. 5℃ in winter and ca. 2-3℃ in summer. Winter cooling is consistent with previous quantitative estimates from New Zealand. Mean annual precipitation decreased a maximum 35-40% during stadials. Temperatures and precipitation varied during OIS 3/2 indicating multiple possible drivers for glaciation. A glacial advance ca. 34-28ka BP correlates with ca. 5℃ winter cooling and ca. 40% less precipitation, which supports temperature driven glaciation whereas a glacial advance ca. 24-22ka BP correlates with ca. 3℃ winter cooling and precipitation similar to present, which supports precipitation forced glaciation. Palaeoenvironmental reconstructions of stadial vegetation from the Westport region indicate lowland Nothofagus fusca-type forest during OIS 4 and a forest-grassland mosaic during OIS 3/2. These records contrast with pollen-based reconstructions of a treeless landscape in Westport during stadials but are consistent with quantitative estimates of stadial cooling. A shift of reproductive strategy in arboreal vegetation may explain the lack of tree pollen in stadial pollen records. This is significant for our understanding of glacial palaeoecology and palaeoclimatology as pollen records may not accurately represent stadial vegetation.

    View record details
  • Emotion-Focussed Psychoeducational Group Therapy for Binge Eating Disorder in Women and Men.

    Clyne, Courtney (2007)

    Doctoral thesis
    University of Canterbury Library

    A plethora of research has linked negative affect with binge eating in people with binge eating disorder (BED). Cognitive behavioural therapy (CBT) and interpersonal therapy (IPT) have not traditionally addressed emotional regulation deficits. Failure to address emotional aspects of binge eating may explain why some individuals do not respond to CBT or IPT, and why many of those who do respond relapse shortly after finishing treatment. Dialectical behaviour therapy (DBT) specifically targets the inability to accurately recognise and regulate affect. Preliminary investigations have shown that DBT may be efficacious in treating BED. However, it can take up to 10 months, and a shorter intervention targeting affect regulation and recognition may produce similar effects. Four studies evaluating a ten session emotion-focussed group psychoeducational intervention for BED were conducted. In the first, 25 women diagnosed with subthreshold or full syndrome BED (using DSM-IV-TR criteria) were treated. The second study tested whether the specific components of the intervention, or the treatment as a whole, was required to produce positive outcomes in women. Study three, examined the efficacy of the treatment programme with three men diagnosed with subthreshold or full syndrome BED (also using DSM-IV-TR criteria). The fourth study compared the women's and men's response to treatment. Following the intervention with women, binge abstinence rates, comparable to those of CBT and IPT, and various other positive changes to eating and general pathology, were observed. These effects were well-maintained up to one-year later. Overall, it was concluded that the whole treatment programme was necessary to produce the optimum outcome for BED in women. A positive outcome was measured in the men, although the effects were not as dramatic as those found in the women. Suggestions for improvements, and suggestions for further research, are discussed. The results provide support for the Affect Regulation Model of BED in women and men.

    View record details
  • Chiral Heterocyclic Ligands

    Lewis, William (2007)

    Doctoral thesis
    University of Canterbury Library

    This thesis describes the preparation and characterisation of a number of homochiral coordination and metallosupramolecular assemblies. These species were formed from the reaction of chiral pyridine and quinoline containing ligands and metal ions. The combination of traditional coordination chemistry and supramolecular interactions led to a range of polymeric and network structures being formed. The ligands used in this thesis can be divided into two broad categories: alkaloids and ligands derived from them, and amino acid-based ligands. In the first category three new ligands were synthesized, and a variety of routes towards alkaloid-based homochiral ligands were investigated. The second category focused on three ligand motifs, and resulted in the preparation of 16 ligands. These two categories of ligands were reacted with a range of metal salts to investigate their coordination and supramolecular chemistry. The structure of twenty complexes was determined by single crystal X-ray crystallography. The complexes had a range of structures, with discrete and polymeric species being formed. Hydrogen bonding was an important feature in the supramolecular chemistry of the complexes, playing a different role in different series of complexes. Two chiral coordination polymers and one chiral coordination network were synthesized. All three of these structures possessed directionality to some degree: in the coordination network and one of the polymers the directionality is counterbalanced by the opposite directionality being present in the crystal, while the second coordination polymer is generated by the screw axis present and has a high degree of overall directionality.

    View record details
  • Nano Scale Cluster Devices

    Reichel, René (2007)

    Doctoral thesis
    University of Canterbury Library

    This study uses clusters formed in a UHV-compatible cluster apparatus, which was built and commissioned during this thesis. The design and operation of the cluster deposition system is described. This system is optimised for high clus- ter fluxes and for the production of cluster assembled nanoscale devices. One key feature of the system is a high degree of flexibility, including interchangeable sputtering and inert gas aggregation sources, and two kinds of mass spectrome- ter, which allow both characterisation of the cluster size distribution and deposi- tion of mass-selected clusters. Another key feature is that clusters are deposited onto electrically contacted lithographically defined devices mounted on an UHV- compatible cryostat cold finger, allowing deposition at room temperature as well as at cryogenic and at elevated temperatures. The electrically contacted nanoscale cluster devices were fabricated using a novel template technique. Hereby, clusters are placed between two electrodes separated only by ∼100 nm. The width of the cluster ensemble is in the order of a few cluster diameters, which means that the assembled clusters form a cluster wire bridging the electrode separation. During this thesis, the design and layout has been optimised to be able to measure electrical properties of the cluster devices and in particular to investigate the interaction between the cluster ensemble and the contact electrodes. In-situ electrical characterisation of cluster assembled nanoscale devices are performed in the temperature range 4.2 K to 375 K. The samples are provided with a backgate, which in principle allows modification of the conduction through the cluster ensemble by applying a gate voltage. However, no change in conduc- tion with changes in gate voltages was seen. The main focus of the electrical measurements is on the current voltage char- acteristics. It was noticed that the nanoscale bismuth (and antimony) cluster devices exhibited non-linear current voltage characteristics, which were in stark contrast to the linear current voltage characteristics measured for cluster films previously. Investigations into the causes of this non-linearity suggests that tun- nelling conduction occurs between the cluster ensemble (wire) and the contact electrodes. The non-linear current voltage characteristics were fitted using three models of tunnelling conduction and appear to be best fitted using a model in- volving fluctuation-assisted tunnelling through barriers of different heights. Further, measurements of the temperature dependent resistance are performed showing an increase of resistance with decreasing temperature for bismuth and antimony assembled cluster devices. The temperature dependence of bismuth as- sembled cluster wires can be explained by the decrease of the carrier concentration in bismuth for decreasing temperature. Annealing of the cluster ensemble and the cluster contact connection resulted in an increase in conduction. This increase of conduction can be explained due to the current flow through the cluster wire. Locally, at the bottlenecks, the current flow causes resistive heating and subsequently coalescence of two (or more) clusters.

    View record details
  • Examining the relationship between oral narrative ability and reading comprehension in children with mixed reading disability

    Westerveld, Marleen Frederike (2007)

    Doctoral thesis
    University of Canterbury Library

    Oral narrative ability has received increasing attention over the past three decades, and the importance of children's oral narrative skills to academic achievement has been well established. Children with reading disabilities are known to demonstrate difficulties in the ability to produce and comprehend oral narratives (Roth & Spekman, 1986; Snyder & Downey, 1991). However, the nature of the relationship between oral narrative ability and reading comprehension performance in children with reading disability is not clear. The experiments reported in this thesis aim to address this issue. The following questions are asked: 1) Do deficits in oral narrative ability contribute to reading comprehension difficulties? and 2) What is the likely direction of the relationship between aspects of oral narrative ability and reading comprehension performance in children with reading disabilities? Fourteen children (aged between 6;4 and 7;8 at the initial assessment) with mixed reading disability (MRD: i.e., children who demonstrate both word recognition and listening comprehension deficits) participated in the study. Their oral narrative skills were compared to those of their chronological age-matched peers with typical development (TD) and their reading-age-matched peers with typical development (RMTD). The study consisted of three phases: 1) A longitudinal phase in which the children's oral narrative performance was assessed on three occasions over a two-year period; 2) An intervention phase (using a nonequivalent pretest-posttest control group design) in which 10 children participated in an oral narrative intervention program that focused on enhancing children's story structure knowledge; and 3) A follow-up assessment phase conducted eight months post-intervention. Oral narratives were elicited in a personal narrative context and in a story retelling context. Oral narrative production ability was analysed at macrostructure (story quality) and microstructure (morpho-syntax and vocabulary) levels. Oral narrative comprehension was assessed in a fictional story context through questions relating to story structure elements. Reading comprehension performance was assessed using a standardised test of reading ability. The results from the longitudinal study showed that the children with MRD demonstrated inferior oral narrative production and oral narrative comprehension performance compared to their peers with typical reading development at each assessment occasion. When comparing the poor readers' performance to the RMTD group at the third assessment trial, the results suggested that the children with MRD demonstrated a specific deficit in oral narrative comprehension. In contrast, a pattern of delay was observed on the microstructure measures of oral narrative performance. The results from the intervention indicated significant treatment effects with large effect sizes for oral narrative comprehension performance. Despite this improvement in oral narrative comprehension, there was little change in oral narrative production ability, and transfer to reading comprehension was not evident. Although the follow-up assessment indicated sustained improvement in oral narrative comprehension for the children with MRD, accelerated reading comprehension progress was not evident. The findings from the longitudinal case study highlighted the benefits of oral narrative intervention for a child considered at high risk of continuing academic difficulties. This thesis provides evidence of the persistent oral narrative difficulties in children with MRD. The findings also provide support for the importance of narrative structure knowledge to these poor readers' oral narrative comprehension performance. The results demonstrate that oral narrative comprehension ability explains only a small amount of the variance in reading comprehension performance. Rather, the persistent word recognition difficulties of the children with MRD exert the biggest influence on their reading comprehension performance. These results are discussed in terms of current models of reading and language development. Implications for clinical practice are also addressed.

    View record details
  • The Coupling of Dynamics and Chemistry in the Antarctic Stratosphere

    Huck, Petra Ellen (2007)

    Doctoral thesis
    University of Canterbury Library

    This thesis addresses the parameterisation of chemical and dynamical processes in the Antarctic stratosphere. Statistical models for the inter- and intra-annual variability in Antarctic stratospheric ozone depletion were developed based on theory and an understanding of the coupling of dynamics and chemistry in the atmosphere. It was confirmed that the primary driver of the long-term trend in the severity of the Antarctic ozone hole is halogen loading in the stratosphere. The year-to-year variability in ozone mass deficit, a measure of the severity of Antarctic ozone depletion, could be described by a linear combination of South Pole temperatures and midlatitude wave activity. A time lag of two weeks between wave activity effects and ozone depletion indicates the predictive capability of meteorological parameters for seasonal projections of the severity of the Antarctic ozone hole. The statistical model describing the inter-annual variability in ozone mass deficit was regressed against observations from 1979 to 2004. The resulting regression coefficients were applied to South Pole temperature and wave activity fields from 28 chemistry-climate models. This analysis indicates a slight increase in the year-to-year variability in the severity of Antarctic ozone depletion. As a prelude to analysing the seasonal evolution of Antarctic ozone depletion, an improved ozone mass deficit measure was derived by replacing the constant 220 DU threshold with a seasonal varying pre-ozone hole background which leads to better capturing the true extent of the depleted ozone. Furthermore, it was shown that the new measure represents the chemical ozone loss within the Antarctic vortex provided that no mixing occurs through the vortex boundary. This new measure has many advantages over previous stratospheric ozone depletion indices. The conventional ozone mass deficit omits large amounts of depleted mass of ozone, and the onset of ozone depletion does not coincide with the timing of when sunlight first reaches areas of polar stratospheric clouds as expected from theory. Chemical ozone loss derived with a tracer-tracer correlation technique depends on ozone and passive tracer profile measurements which are not as readily available as the total column ozone fields required for the new ozone mass deficit presented in this thesis. As such, the new ozone depletion measure combines the simplicity of the old ozone mass deficit index with higher accuracy of the actual amount of chemically depleted stratospheric ozone. Furthermore, when applying the new definition of ozone mass deficit to chemistry-climate model outputs, model intercomparisons should become easier to interpret because biases in the models can be avoided. Based on theory and understanding of the coupling of chemistry and dynamics in the Antarctic stratosphere, two semi-empirical models were developed to describe the intra-seasonal evolution of chlorine activation and ozone depletion. Regression of the models against chlorine monoxide and ozone mass deficit from observations results in coefficients that capture key sensitivities in the real atmosphere. The seasonal evolution of ozone mass deficit can be described with these coefficients and readily available meteorological fields (temperature and wind fields). The predictive capability of these models was demonstrated for 2005 and 2006. Given temperature and wind fields, which for example can be obtained from general circulation models, these models can predict the size and depth of the Antarctic ozone hole. Important applications of the semi-empirical models could be chemistry-climate model validation by comparing the sensitivities from observations and models which may provide new insights into potential sources of differences in chemistry-climate model projections of Antarctic ozone depletion. Furthermore, projection of the inter-annual and intra-seasonal evolution of the Antarctic ozone hole into the future can help to assess the potential recovery of the Antarctic ozone hole.

    View record details
  • The development of resilience - a model

    Maginness, Alison (2007)

    Doctoral thesis
    University of Canterbury Library

    The impetus for this study grew from observations in clinical practice that many individuals survived all sorts of hardships with minimal distress, or with the ability to tolerate their distress, and move on with their lives in a positive manner. A review of the literature led to the conclusions that the research investigating resilience was making minimal inroads into understanding what made these people different, and that the richness of who they were was being lost in the scientific process. This dissatisfaction led to the decision to explore the construct from a phenomenological framework, and to try and discover the essential elements of resilience through analysis of the subjective experience of resilience. A qualitative study involving thirteen participants identified by their peers as resilient was undertaken and the underlying themes of their stories were analysed. This led to the development of a model of resilience that attempted to balance the need for parsimony with that of explanatory breadth, and which had the potential to tolerate the complexity and instability of the construct itself. The model developed identified three core elements that embraced the construct of resilience. These included the physiological capacity to be resilient, and from this basis the ability to be adaptive and the ability to maintain well-being emerge. Factors identified with these elements include individual reactivity to and recovery from adverse events, the ability to be effective and efficient in the management of adverse events, and the beliefs about the world and the self that promote well-being when exposed to adverse events. The model has a basis within neurobiology and is framed within the context of Dynamic Systems Theory. The theory itself is a culmination of clinical observations with what is known from within the current literature and the results of this study.

    View record details
  • The population dynamics of a riparian spider: interactive effects of flow-related disturbance on cross-ecosystem subsidies and spider habitat

    Greenwood, Michelle Joanne (2007)

    Doctoral thesis
    University of Canterbury Library

    The transfer of prey resources between ecosystems can have dramatic consequences for both recipient and donor systems by altering food web stability and the likelihood of trophic effects cascading across the ecosystem boundary. Landscape-scale factors influence the importance, direction and magnitude of energy flows, but may also alter the ability of consumer organisms to respond to spatio-temporal changes in allochthonous prey availability. Here, I used flood and drying disturbance gradients to investigate interactions between these two processes on populations of a riparian fishing spider Dolomedes aquaticus (Pisauridae). The abundance of aquatic insects with a winged adult stage, a major component of the diet of D. aquaticus, was markedly higher at less flood-prone rivers and declined with increasing flood disturbance. It was expected that spider populations would be largest at these stable rivers where the aquatic prey abundance was highest. However, a habitat (loose, unembedded riverbank rocks) manipulation revealed that the lack of scouring floods at these sites led to habitat-limited populations, preventing response to the increased prey resource. In fact a peak shaped relationship of spider biomass and abundance was found, with the largest spider populations at intermediately disturbed rivers. In addition, patchy habitat availability was the most likely cause of the small scale (4 m2) aggregation of spiders seen at the most stable and disturbed rivers. These patterns were also associated with strong interactions between the spiders. Stable isotope analysis of field collected spiders and an experimental manipulation of spider densities and food availability indicated that cannibalism rates were likely to be significantly higher at stable and disturbed rivers than those intermediate on the disturbance gradient. Differences in D. aquaticus population size structure and life history traits across the flood disturbance gradient were driven by interactions between resource availability, environmental stability and cannibalism rates. To separate the effects of habitat availability and aquatic prey abundance I used drying rivers, as the amount of aquatic insect prey alters as the water recedes. Desiccation mortality and low aquatic prey biomass most likely caused the spiders' spatial distribution and size class structure to alter in drying river reaches, potentially also leading to differences in cannibalism rates. Overall, cross-ecosystem transfers of prey had large impacts on the distribution, cannibalism rates and life history traits of D. aquaticus but their effects were modified by the nature of the ecosystem boundary. Thus river flow regime controlled the magnitude of the subsidy and its use by a consumer. Hence, cross-ecosystem subsidies will not always lead to larger consumer populations and consumer responses will depend on interactions between large-scale processes.

    View record details
  • Mechanisms of airway protection in ageing and Parkinson's disease

    Leow, Li Pyn (2007)

    Doctoral thesis
    University of Canterbury Library

    Safe and efficient swallowing requires integrity of both motor and sensory systems. Prior studies have established that motor impairment in individuals with PD frequently manifests as abnormalities in swallowing biomechanics. In contrast, very few studies have investigated the contribution of sensory impairment towards pharyngeal biomechanics and airway protection in this patient cohort. This area should be addressed in light of evidence that the severity of limb motor dysfunction in PD does not reliably predict severity of dysphagia. Emerging data suggests that dysphagia in PD cannot be solely attributed to motor impairment, but may also be influenced by deficits in sensory aspects of airway protection. As an example, silent aspiration in up to 100% has been reported in individuals with PD due to laryngopharyngeal sensory deficits have. Even so, current research lacks information on the integration of both motor and sensory components that make up the swallowing process. The aim of this study was to document changes in airway protection with age, in PD and across severity levels of PD. The project was comprised of two parts. In part one, three parallel studies were conducted to assess a series of both motor and sensory airway mechanism (Chapters 4 to 9). In the first study, 16 young (8 males, age range 21.3 - 32.4) and 16 elder adults (8 males, age range 61.5 - 84.7), were assessed to investigate changes in airway protection that accompany ageing. In the second study, data from individuals diagnosed with PD across severity levels (Hoehn-Yahr 1 - 4, age range 64.2 - 84.5) were age and gender-matched to 16 healthy elders in order to examine the effects of PD on airway protection. In the third, the impact of disease severity was studied with data from 16 individuals in the earlier stages (Hoehn-Yahr ≤ 2, 13 males, age range 51.3 - 82.5, ) compared to 16 individuals in the later stages (Hoehn-Yahr ≥ 2.5, 10 males, age range 61.5 - 78.9). In part two of this project, two smaller, pilot studies were completed to probe the influence of pharmacologic and behavioural treatments on airway protection mechanisms. In the first pilot study, the effect of pharmacotherapy on airway protection was investigated in 10 patients 'on' and 'off' levodopa (Chapter 10). In the second study, 5 patients were assessed before and after completing the Lee Silverman Voice Treatment (LSVT) to document effects of speech rehabilitation on airway protection (Chapter 11). Multimodality assessment elicited data from all participants on both motor and sensory components of airway protection (Chapter 3). Specifically, breathing-swallowing coordination (BSC) and swallowing apnoea (SA) were captured using simultaneous directional nasal airflow and surface electromyography (sEMG). Standard, closed-loop spirometry was used to assess pulmonary function. Swallowing biomechanics were screened using a validated timed test of swallowing efficiency and further evaluated using fibreoptic endoscopic evaluation of swallowing (FEES). Finally, chemo-sensation of the laryngopharynx was determined with the administration of the inhalation cough challenge while mechanosensation was examined using FEES. Results suggest that motor control for airway protection is reasonably robust in PD, although sensory response is impaired. The predominant pattern for swallowing respiratory coordination was mid-expiration for all participants regardless of age and disease severity (Chapter 4). Individuals with PD demonstrated a reduction in average time and volume per swallow, leading to an overall decrease in swallowing capacity (Chapter 5). No difference was found for swallowing efficiency between those in early and later stages of PD. Pulmonary function measures were not significantly different as a function of age, PD or PD severity (Chapter 6). In summary, results from motor assessments contributing to airway protection support the robustness of breathing-swallowing coordination (BSC) and pulmonary function across research groups, but identify a reduction in overall swallowing efficiency in PD. Results from sensory assessments contributing to airway protection revealed that chemosensation was not different between age groups but base of tongue mechano-sensation was diminished in individuals with PD. Natural cough thresholds did not differ between young adults and elders but when asked to stifle coughing, elders were less able to do so compared to young adults (Chapter 7). For the first time, a reduction in mechano-reception at the base of tongue was recorded in individuals with PD (Chapter 8). These patients also demonstrated increased post swallow residual (Chapter 5), which offers an explanation for the complaint of globus in this population. These assessments highlight some compromise to sensory aspects of airway protection in PD. Overall, dysphagia had a negative impact on the quality of life of individuals with PD and even more as disease severity progresses (Chapter 9). Results from part two of the study looking at the effects of therapeutic interventions on airway protection revealed some unexpected findings. In chapter 10, results showed a reduction in pulmonary function when 'on' levodopa, but no differences in swallowing efficiency, BSC, or laryngopharyngeal chemo- and mechano-reception were observed. These results suggested a reduction in pulmonary function with levodopa without any increase in risk of airway protection compromise1. Unexpectedly and documented for the first time, the percentage of post swallow inspiration increased after LSVT (Chapter 11) but as with the levodopa study, this was also not accompanied by any apparent increase in aspiration risk. An increase in submental surface electromyography (sEMG) amplitude across all 5 participants may serve as a proxy measure of improvement in hyolaryngeal excursion. Finally, participants reported an overall improvement in social functioning and communication after LSVT. In conclusion, this study provided evidence that mechano-sensory aspect of airway protection is diminished in individuals with PD, possibly compromising airway protection. Patients not only demonstrated increased residue but the lack of sensation may prevent clearing or spontaneous multiple swallows. Overall, airway protection is maintained in ageing but swallowing efficiency declines in the presence of PD. This study contributes significantly to current research efforts in PD by expanding on existing reports regarding motor aspects of airway protection. Specifically, BSC, swallowing efficiency and evaluation of biomechanics using FEES research have never before been investigated exclusively in the PD population. Finally, the chemo- and mechano-sensation evaluated in this study are an important addition to the limited evidence that sensory impairment in individuals with PD potentially compromises airway protection. Results of the present study will serve as a platform upon which future studies may compare and expand.

    View record details