12,847 results for Doctoral

  • Bacterial sialic acid degradation: membrane transport and enzymology

    North, Rachel Aimee (2016)

    Doctoral thesis
    University of Canterbury Library

    The overarching aim of this thesis is to understand how sialic acids are transported into the bacterial cell and then degraded by bacterial pathogens. In heavily sialylated environments, bacterial pathogens utilise host-derived sialic acid as a nutrient source, and this pathway constitutes a novel and unexploited target for antibiotic drug design. Three sialic acid transporters, from two distinct gene families were investigated to probe how sialic acid is transported across the cytoplasmic membrane. The Yersinia pestis sugar proton symporter (NanT) exists as a single species in solution, while the Staphylococcus aureus sodium solute symporter (SSS) and Proteus mirabilis SSS appear to be in a selfassociation. It is likely that the SSS sialic acid transporters exist in a monomer-dimer equilibrium, although higher oligomeric structures cannot be ruled out. The structure of the P. mirabilis SSS sialic acid transporter was solved, which is the first known structure of a sialic acid transporter to be presented. It was solved in complex with sialic acid and two sodium ions, providing insight into how this transporter mediates the movement of sialic acid across the membrane. In addition, the structure presents a novel conformation among sodium symporters and the structural basis for the movement of sialic acid across the membrane is elucidated. Following the import of sialic acid into the bacterial cell, N-acetylneuraminate lyase is the first enzyme involved in its degradation. The structure, function and inhibition of methicillin-resistant S. aureus (MRSA) N-acetylneuraminate lyase were investigated. Solution and structural studies confirmed that this enzyme is tetrameric. Kinetic analysis was employed to test an inhibitor of N-acetylneuraminate lyase enzymes. This molecule demonstrated strong species-specific inhibition against MRSA N-acetylneuraminate lyase. The structure of MRSA N-acetylneuraminate lyase in complex with this inhibitor demonstrated that altered binding modes between N-acetylneuraminate lyase enzymes may account for variable inhibition between species. In addition, evidence for a protein-protein interaction between the S. aureus SSS sialic acid transporter and MRSA Nacetylneuraminate lyase is presented. Thus, these proteins may interact at the cytoplasmic membrane, allowing the degradation of sialic acid to be initiated upon entering the cell. The structure, function and catalytic mechanism of the third enzyme involved in sialic acid degradation, N-acetylmannosamine-6-phosphate 2-epimerase, were explored from MRSA. This enzyme was demonstrated to adopt a dimeric architecture in solution, consistent with the crystal structure that was solved and presented. A multi-enzyme coupled assay was developed to assess N-acetylmannosamine-6-phosphate 2-epimerase activity in real time. Residues were probed that may be important for catalysis and tested by mutagenesis and kinetic analysis. A novel mechanism of carbohydrate epimerisation is proposed for this enzyme, whereby catalysis occurs via a proton displacement mechanism mediated by the substrate. Overall, this work provides new data that enriches our understanding of the import and degradation of sialic acid in clinically important human bacterial pathogens.

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  • Paleoseismicity and Rupture Characteristics of the Greendale Fault and Formation of the Canterbury Plains

    Hornblow, Sharon (2016)

    Doctoral thesis
    University of Canterbury Library

    The previously unknown Greendale Fault was buried beneath the Canterbury Plains and ruptured in the September 4th 2010 moment magnitude (Mw) 7.1 Darfield Earthquake. The Darfield Earthquake and subsequent Mw 6 or greater events that caused damage to Christchurch highlight the importance of unmapped faults near urban areas. This thesis examines the morphology, age and origin of the Canterbury Plains together with the paleoseismology and surface-rupture displacement distributions of the Greendale Fault. It offers new insights into the surface-rupture characteristics, paleoseismology and recurrence interval of the Greendale Fault and related structures involved in the 2010 Darfield Earthquake. To help constrain the timing of the penultimate event on the Greendale Fault the origin and age of the faulted glacial outwash deposits have been examined using sedimentological analysis of gravels and optically stimulated luminescence (OSL) dating combined with analysis of GPS and LiDAR survey data. OSL ages from this and other studies, and the analysis of surface paleochannel morphology and subsurface gravel deposits indicate distinct episodes of glacial outwash activity across the Canterbury Plains, at ~20 to 24 and ~28 to 33 kyr separated by a hiatus in sedimentation possibly indicating an interstadial period. These data suggest multiple glacial periods between ~18 and 35 kyr which may have occurred throughout the Canterbury region and wider New Zealand. A new model for the Waimakariri Fan is proposed where aggradation is mainly achieved during episodic sheet flooding with the primary river channel location remaining approximately fixed. The timing, recurrence interval and displacements of the penultimate surface-rupturing earthquake on the Greendale Fault have been constrained by trenching the scarp produced in 2010 at two locations. These excavations reveal a doubling of the magnitude of surface displacement at depths of 2-4 m. Aided by OSL ages of sand lenses in the gravel deposits, this factor-of-two increase is interpreted to indicate that in the central section of the Greendale Fault the penultimate surface-rupturing event occurred between ca. 20 and 30 kyr ago. The Greendale Fault remained undetected prior to the Darfield earthquake because the penultimate fault scarp was eroded and buried during Late Pleistocene alluvial activity. The Darfield earthquake rupture terminated against the Hororata Anticline Fault (HAF) in the west and resulted in up to 400 mm of uplift on the Hororata Anticline immediately above the HAF. Folding in 2010 is compared to Quaternary and younger deformation across the anticline recorded by a seismic reflection line, GPS-measured topographic profiles along fluvial surfaces, and river channel sinuosity and morphology. It is concluded that the HAF can rupture during earthquakes dissimilar to the 2010 event that may not be triggered by slip on the Greendale Fault. Like the Greendale Fault geomorphic analyses provide no evidence for rupture of the HAF in the last 18 kyr, with the average recurrence interval for the late Quaternary inferred to be at least ~10 kyr. Surface rupture of the Greendale Fault during the Darfield Earthquake produced one of the most accessible and best documented active fault displacement and geometry datasets in the world. Surface rupture fracture patterns and displacements along the fault were measured with high precision using real time kinematic (RTK) GPS, tape and compass, airborne light detection and ranging (LiDAR), and aerial photos. This allowed for detailed analysis of the cumulative strike-slip displacement across the fault zone, displacement gradient (ground shear strain) and the type of displacement (i.e. faulting or folding). These strain profiles confirm that the rupture zone is generally wide (~30 to ~300 metres) with >50% of displacement (often 70-80%) accommodated by ground flexure rather than discrete fault slip and ground cracking. The greatest fault-zone widths and highest proportions of folding are observed at fault stepovers.

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  • Oocyte-derived forms of ruminant BMP15 and GDF9 and a theoretical model to explain their synergistic response

    Heath, Derek (2016)

    Doctoral thesis
    Victoria University of Wellington

    Bone morphogenetic factor 15 (BMP15) and growth differentiation factor 9 (GDF9) are two oocyte-secreted factors with well documented effects on ovarian follicular development and ovulation-rate. The aims of these studies were to: (i) identify the molecular forms of BMP15 and GDF9 that are produced and secreted by both the ovine and bovine oocyte using highly specific monclonal antibodies; (ii) assess the biological activity of some recombinant molecular forms of BMP15 and GDF9; (iii) visualise the various molecular forms using protein modelling techniques and; (iv) provide a hypothetical model of how oocyte-secreted form(s) of BMP15, GDF9 and their cell surface receptors may interact. Using genetic modifications and transformations of HEK293 cells, recombinant forms of ovine (o) BMP15, including a BMP15 (S356C) mutant capable of forming covalent dimers, and oGDF9 were produced. The bioactivity of these proteins was established using a rat granulosa cell proliferation bioassay. The specificity of the monoclonal antibodies MN2-61A (anti-BMP15) and 37A (anti-GDF9) used in these studies, and determination of the forms they recognise, was examined by Western blotting. The recombinant forms of oBMP15 were further interrogated by purification using both immobilised metal affinity chromatography (IMAC) and reverse phase HPLC. The BMP15 and GDF9 proteins produced and/or secreted by ovine and bovine oocytes, before and after in vitro incubation, were identified and compared with the molecular forms(s) of recombinant oBMP15 or oGDF9 using Western blotting under non-reducing, reducing and cross-linking conditions. The molecular forms of recombinant oBMP15 and oGDF9 comprise mainly mature monomers with a lesser amount of the uncleaved pro-mature form. Mature domains, in the dimeric mature form, were detected for oGDF9 and oBMP15 (S356C), but not oBMP15. These mature domains were almost entirely located within high molecular weight multimeric complexes, which likely also contain the pro-region. In contrast, BMP15 and GDF9 secreted from ruminant oocytes under in vitro conditions were found mainly in an unprocessed promature form, along with some fully processed mature domains that did not interact to form detectable mature homodimers or heterodimers. Throughout ovarian follicular development, BMP15 and GDF9 are co-expressed and it has been established that these two factors have synergistic effects on granulosa cell proliferation both in vitro and in vivo and also on follicular maturation and ovulation-rate in vivo. Moreover, the recombinant proteins oBMP15 and oGDF9 generated for this study, when added together, also demonstrated a synergistic effect in the granulosa cell proliferation assay but this was not observed for oBMP15 (S356C) and oGDF9. Currently, no adequate model has been proposed to explain how interactions between the cell membrane and forms of oocyte-derived BMP15 and GDF9 achieve their synergistic effects. To investigate this, two homology models of the promature BMP15 and GDF9 proteins were generated using promature porcine TGFB1 and human BMP9 as templates. These models, together with the previously determined forms of GDF9 and BMP15 produced by the ruminant oocyte, were used to visualise their potential interactions, both with each other and with their receptors. This report describes a model showing the possible interactions involved in a synergistic response. In this model, the mature domain is presented to the type II receptor by the proregion and heterodimers form at the level of the receptor. Differences, following heterodimerisation in the conformation and orientation between GDF9 and its type I receptor, as well as between type I and type II receptors, relative to that in homodimers, could explain how heterodimerisation leads to increased Smad3 phosphorylation and subsequent down-stream somatic cell responses.

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  • Improving the Performance of Cloud-based Scientific Services

    Chard, Ryan (2016)

    Doctoral thesis
    Victoria University of Wellington

    Cloud computing provides access to a large scale set of readily available computing resources at the click of a button. The cloud paradigm has commoditised computing capacity and is often touted as a low-cost model for executing and scaling applications. However, there are significant technical challenges associated with selecting, acquiring, configuring, and managing cloud resources which can restrict the efficient utilisation of cloud capabilities. Scientific computing is increasingly hosted on cloud infrastructure—in which scientific capabilities are delivered to the broad scientific community via Internet-accessible services. This migration from on-premise to on-demand cloud infrastructure is motivated by the sporadic usage patterns of scientific workloads and the associated potential cost savings without the need to purchase, operate, and manage compute infrastructure—a task that few scientific users are trained to perform. However, cloud platforms are not an automatic solution. Their flexibility is derived from an enormous number of services and configuration options, which in turn result in significant complexity for the user. In fact, naïve cloud usage can result in poor performance and excessive costs, which are then directly passed on to researchers. This thesis presents methods for developing efficient cloud-based scientific services. Three real-world scientific services are analysed and a set of common requirements are derived. To address these requirements, this thesis explores automated and scalable methods for inferring network performance, considers various trade-offs (e.g., cost and performance) when provisioning instances, and profiles application performance, all in heterogeneous and dynamic cloud environments. Specifically, network tomography provides the mechanisms to infer network performance in dynamic and opaque cloud networks; cost-aware automated provisioning approaches enable services to consider, in real-time, various trade-offs such as cost, performance, and reliability; and automated application profiling allows a huge search space of applications, instance types, and configurations to be analysed to determine resource requirements and application performance. Finally, these contributions are integrated into an extensible and modular cloud provisioning and resource management service called SCRIMP. Cloud-based scientific applications and services can subscribe to SCRIMP to outsource their provisioning, usage, and management of cloud infrastructures. Collectively, the approaches presented in this thesis are shown to provide order of magnitude cost savings and significant performance improvement when employed by production scientific services.

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  • Intertextuality in Kenyan Policy Discourse on the Rights of Women

    Aberi, George (2016)

    Doctoral thesis
    Victoria University of Wellington

    The investigative aim of this thesis is to explore the recontextualization of the normative discourse of gender equality in Kenya’s policy discourse of women’s rights. Its purpose is threefold: Firstly, it attempts to examine the different ways in which policy makers use language in the course of interpreting and implementing gender equality policies. This includes a focus on both the linguistic and rhetorical/discursive strategies that these policy makers employ for such functions as endorsing, negotiating, legitimating, or even contesting given policy proposals. Secondly, the thesis endeavours to bring to light the different and changing conceptions of gender (in)equality espoused by the various policy actors involved in Kenya’s policy discourse of women’s rights over a critical ten-year period between 1995 and 2005. These policy actors include the Kenyan government; women’s non-governmental organizations (NGOs) who actively seek to influence government policy; and the United Nations’ organizations with responsibility for ensuring the implementation of women’s human rights. Thirdly, the thesis attempts to show the extent to which policy initiatives proposed by the human rights-based women’s NGOs in Kenya are taken up in the texts produced by the Kenyan government. In order to gain a better understanding of the discursive interactions between and amongst the policy actors in this study, an intertextual approach to Norman Fairclough’s model of critical discourse analysis (CDA) was used. The thesis drew discourse samples for analysis from the Kenyan government’s periodic reports detailing progress towards fully meeting the terms of the Convention on the Elimination of Discrimination Against Women (CEDAW); the documents produced by the Committee overseeing the Convention that provided assessment of the Kenyan government’s reports; the Kenyan government’s official texts on gender policy; and Kenyan women NGOs’ annual reports and other texts. Though many scholars and researchers of women’s rights praise the UN Committee’s imperatives for bringing about policy changes concerning women’s rights globally, the findings from this study confirm that the Committee for CEDAW has only textual power, and that it lacks enforcement powers to ensure the implementation of the universal rights of women within the local milieu. In a similar vein, this study demonstrates that though the women’s NGOs play a significant role both in terms of identifying important areas of concern for policy intervention, and in necessitating changes in the genres of the national government, their participation has largely failed to ensure the Kenyan government’s epistemological shift from its current state of recognizing the existence of women’s rights, to the phase of implementing them. This thesis also establishes that differing conceptions of gender (in)equality and ideological differences between the Committee for CEDAW and the Kenyan government tend to influence both the Committee’s and the Kenyan government’s use of varied discourses, genres, and styles, with the intent of manipulating to outmanoeuvre one another. This means that both the Kenyan government and the Committee live in different worlds, suggesting a continuing gap between the Committee’s normative knowledge of women’s rights to gender equality, and the Kenyan government’s cultural relativist perspectives concerning such rights. As a solution to these power struggles and political differences that derail policy making on gender equality, this study recommends the need both for the Committee and the Kenyan government to employ a reflexive and pragmatic mix of both the universalist and cultural relativist approaches to gender equality. This will bring forth shared areas of interest concerning women’s rights between the UN and the Kenyan government, based on their applicability within the local context. Moreover, such an approach will create a possibility for the Committee to understand the Kenyan government’s cultural relativist/competing discourse of women’s rights as another way of conceiving gender equality (i.e. productive power-knowledges), rather than viewing them as irrelevant cultural claims that stand in stark opposition to the universal understandings of women’s rights to gender equality. Likewise, the aforesaid reflexive and pragmatic mix of approaches will help the Kenyan policy makers to develop a more critical and nuanced view of the universal approaches to gender equality, thereby reducing their varied forms of resistance to gender equality via subtle evasive strategies. Methodologically, this thesis shows how a comparative intertextual approach to Fairclough’s model of critical discourse analysis can be used as a framework for establishing the relations between policy text and context. This framework includes the micro-level of textual/linguistic analysis, the meso level of discursive interactions, and the macro level of socio-cultural practice at the local, institutional, and societal levels. Theoretically, the thesis demonstrates the different ways in which particular philosophical arguments and emancipatory concepts from Foucault’s theory of governmentality and transnational feminist rhetorical theory can be combined and exploited by linguists to promote different ways of theorizing and thinking concerning the development of policies for promoting gender equality.

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  • Receiver design for OFDM transmission with insufficient cyclic prefix.

    Pham, Tri (2016)

    Doctoral thesis
    University of Canterbury Library

    Orthogonal frequency division multiplexing (OFDM) is desirable for broad-band communication because of its high spectral efficiency and resistance to multipath fading. The latter is achieved by adding a cyclic prefix to the beginning of each OFDM symbol. The cyclic prefix length must be equal to or greater than the channel delay spread to avoid multipath interference. For long range transmission, this criterion leads to bandwidth inefficiency. If a shorter cyclic prefix is used, the interference caused corrupts both pilot and data sub-carriers leading to degradation in channel estimation and data detection. This thesis focuses on developing effective receiver designs for multiple antenna orthogonal frequency division multiplexing systems when the cyclic prefix is insufficient. Closed form expressions for the short cyclic prefix induced interference are formulated and analyzed. Based on the analysis, we propose an iterative structure for channel estimation and data detection using a limited number of pilot sub-carriers. First, the number of channel paths is estimated from the channel least squares estimates at the pilot sub-carriers. We then formulate a maximum likelihood process to approximate the channel delay profile and subsequently the individual path coefficients. A search procedure is designed to reduce the estimator's complexity. High performance trellis based equalization schemes are proposed. Two additional data detection methods based on the zero forcing and minimum mean square error criteria are introduced with lower complexity than the trellis equalizers at the cost of performance. Simulation results indicate that the proposed techniques outperform conventional receivers, especially when the trellis equalizer is utilized for data detection. The mean square error of the channel estimate converges to the Cramer-Rao bound after two iterations; and the achieved bit error rate can reach that of the sufficient cyclic prefix case even when the delay spread is significantly longer than the cyclic prefix.

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  • Decision support framework for post-earthquake restoration of sewerage pipelines and systems.

    Liu, Miao (Melanie) (2016)

    Doctoral thesis
    University of Canterbury Library

    Sewerage systems convey sewage, or wastewater, from residential or commercial buildings through complex reticulation networks to treatment plants. During seismic events both transient ground motion and permanent ground deformation can induce physical damage to sewerage system components, limiting or impeding the operability of the whole system. The malfunction of municipal sewerage systems can result in the pollution of nearby waterways through discharge of untreated sewage, pose a public health threat by preventing the use of appropriate sanitation facilities, and cause serious inconvenience for rescuers and residents. Christchurch, the second largest city in New Zealand, was seriously affected by the Canterbury Earthquake Sequence (CES) in 2010-2011. The CES imposed widespread damage to the Christchurch sewerage system (CSS), causing a significant loss of functionality and serviceability to the system. The Christchurch City Council (CCC) relied heavily on temporary sewerage services for several months following the CES. The temporary services were supported by use of chemical and portable toilets to supplement the damaged wastewater system. The rebuild delivery agency -Stronger Christchurch Infrastructure Rebuild Team (SCIRT) was created to be responsible for repair of 85 % of the damaged horizontal infrastructure (i.e., water, wastewater, stormwater systems, and roads) in Christchurch. Numerous initiatives to create platforms/tools aiming to, on the one hand, support the understanding, management and mitigation of seismic risk for infrastructure prior to disasters, and on the other hand, to support the decision-making for post-disaster reconstruction and recovery, have been promoted worldwide. Despite this, the CES in New Zealand highlighted that none of the existing platforms/tools are either accessible and/or readable or usable by emergency managers and decision makers for restoring the CSS. Furthermore, the majority of existing tools have a sole focus on the engineering perspective, while the holistic process of formulating recovery decisions is based on system-wide approach, where a variety of factors in addition to technical considerations are involved. Lastly, there is a paucity of studies focused on the tools and frameworks for supporting decision-making specifically on sewerage system restoration after earthquakes. This thesis develops a decision support framework for sewerage pipe and system restoration after earthquakes, building on the experience and learning of the organisations involved in recovering the CSS following the CES in 2010-2011. The proposed decision support framework includes three modules: 1) Physical Damage Module (PDM); 2) Functional Impact Module (FIM); 3) Pipeline Restoration Module (PRM). The PDM provides seismic fragility matrices and functions for sewer gravity and pressure pipelines for predicting earthquake-induced physical damage, categorised by pipe materials and liquefaction zones. The FIM demonstrates a set of performance indicators that are categorised in five domains: structural, hydraulic, environmental, social and economic domains. These performance indicators are used to assess loss of wastewater system service and the induced functional impacts in three different phases: emergency response, short-term recovery and long-term restoration. Based on the knowledge of the physical and functional status-quo of the sewerage systems post-earthquake captured through the PDM and FIM, the PRM estimates restoration time of sewer networks by use of restoration models developed using a Random Forest technique and graphically represented in terms of restoration curves. The development of a decision support framework for sewer recovery after earthquakes enables decision makers to assess physical damage, evaluate functional impacts relating to hydraulic, environmental, structural, economic and social contexts, and to predict restoration time of sewerage systems. Furthermore, the decision support framework can be potentially employed to underpin system maintenance and upgrade by guiding system rehabilitation and to monitor system behaviours during business-as-usual time. In conjunction with expert judgement and best practices, this framework can be moreover applied to assist asset managers in targeting the inclusion of system resilience as part of asset maintenance programmes.

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  • Coordinated Detection of Micro- and Nanoparticles using Tuneable Resistive Pulse Sensing and Optical Spectroscopy

    Hauer, Peter (2016)

    Doctoral thesis
    Victoria University of Wellington

    The detection and characterisation of micro- and nanoscale particles has become increasingly important in many scientific fields, spanning from colloidal science to biomedical applications. Resistive Pulse Sensing (RPS) and its derivative Tuneable Resistive Pulse Sensing (TRPS), which both use the Coulter principle, have proven to be useful tools to detect and analyse particles in solution over a wide range of sizes. While RPS uses a fixed size pore, TRPS uses a dynamically stretchable pore in a polyurethane membrane, which has the advantages that the pore geometry can be tuned to increase the device's sensitivity and range of detection. The technique has been used to accurately determine the size, concentration and charge of many different analytes. However, the information obtained using TRPS does not give any insight into the particle's composition. In an attempt to overcome this, an experimental technique was developed in order to obtain simultaneous, time-resolved, high-resolution optical spectra of particles passing through the pore. Due to the ordered and controllable fashion in which the particles are guided through the sensing region, this approach has an advantage over diffusion based optical techniques. The experimental setup for the coordinated electrical and optical measurements involves many underlying physical phenomena, e.g. microuidics, electrokinetic effects, and Gaussian beam optics. A significant proportion of this work was therefore devoted to the development and the optimisation of the experimental setup by adapting a commercial TRPS device and a spectrometer with an attached microscope. Methods to engineer the spot size of a Gaussian beam to account for the different pore diameters, and the development of algorithms to filter, analyse and coordinate the recorded data are essential to the technique. The results using fluorescently labelled polystyrene particle sets with diameters from 190nm to 2 µm show that matching rates between the electrical and optical measurements of over 90% can repeatedly be achieved. Mixtures of particle species with similar diameters but with different fluorescent labels were used to demonstrate the technique's capability to characterise the analyte on a particle-by-particle basis and extend the information that can be obtained by TRPS alone. It was also shown that the data acquired with the electrical and optical measurements complement each other and can be used to better understand the TRPS technique itself. The influence of experimental parameters, such as the particle velocity, the beam size and the optical detection volume, on the intensity of the optical signals and the matching rates was studied intensively. These studies showed that the technique requires a careful experimental design to achieve the best results. Overall, the developed technique enhances the particle-by-particle specificity of conventional RPS measurements, and could be useful for a range of particle characterization and bio-analysis applications. Alongside the experiments, semi-analytic modelling and simulations using the Finite Element Method (FEM) were used to understand the particle motion through the pores, to interpret the experimental data, and predict the optical signals. The models were also used to assist the design and the optimization of the experiments. The FEM models were implemented with increasing physical detail and show superior understanding of the TRPS signals compared to the semi-analytic model, which is conventionally used in the TRPS field. The physical phenomena considered included o -axis trajectories, particle-field interactions for both fluid and electric fields, and the non-homogeneous distribution of ions close to the charged membrane and particle interfaces. Several effects which have been observed experimentally could be explained, including the intrinsic pulse height distribution, the current rectification, and the occurrence of bi-phasic pulses, demonstrating the benefits of FEM methods for RPS.

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  • Predicting the Distribution of Acid Volatile Sulfide in Marine Sediment From Colour Analysis of Sediment Profile Images

    Wilson, Peter Stanley

    Doctoral thesis
    Auckland University of Technology

    Measuring the sediment content of acid volatile sulfides (AVS), one indicator of coastal ecosystem functioning and the remineralisation of organic matter, is laborious and therefore rarely considered in routine coastal monitoring. In this thesis, I further develop an approach presented by Bull and Williamson (2001) to estimate the in situ distribution of AVS in subtidal soft sediment from sediment-profile images. I then determine whether this approach is valid at multiple locations in the Hauraki Gulf, New Zealand and investigate sediment chemical properties that may affect the approach. Finally, I apply this approach to assess soft coastal sediment that had been organically enriched by a long-line mussel farm. I first established a strong correlation (R² = 0.95) between sediment AVS concentration (extracted by cold 1 M HCl) and the colour intensity of sediment collected at 12 m water depth off the eastern coast of Waiheke Island, New Zealand. I then used this AVS/colour correlation to estimate the distribution of AVS in the upper 20 cm of this sediment from sediment profile images. These images were obtained in situ with a lightweight imaging device consisting of a modified flatbed scanner housed inside a watertight acrylic tube (SPI-Scan™, Benthic Science Ltd.). I made two types of estimates from the acquired images: First, I obtained a vertical AVS concentration profile by averaging the colour intensities of horizontally aligned pixels. Second, I created a two-dimensional distribution plot of AVS concentration by assigning individual pixel colour intensities. I determined whether this approach was valid at other locations by establishing an AVS/colour correlation at each of three locations in the Hauraki Gulf, New Zealand. The slopes of the fits that best described the data at each location were similar, however, the positions of the fits along the grey scale axis were offset. That is, the AVS/colour correlation was site specific and, consequently, combining the data from three locations did not produce an AVS/colour correlation that could accurately predict the sediment AVS concentration at all three locations. I suggested that the observed grey value offsets were caused by differences in the background colour of the sediment, that is, caused by sediment components other than AVS. I investigated the sediment sulfur chemistry at these three locations to determine the cause of differences in the AVS/colour correlation between locations. Using a sequential extraction technique, I measured three pools of sedimentary sulfides: dissolved porewater sulfide, AVS, and sequentially extracted chromium reducible sulfide (CRSs). Dissolved porewater sulfides contribute to the total AVS concentration but not to the sediment colour. The constituents of CRSs, however, contribute to the sediment colour but not to the total AVS concentration. The analysis revealed that the concentration of dissolved porewater sulfides was negligible. It also revealed that the relative proportions of AVS and CRSs were functions of sediment age. Sediment at greater depth in the sediment column contained greater proportions of CRSs than surficial sediment because it was older. Black mineral pyrite was the main constituent of CRSs. The transformation of pyrite from its precursors can take up to several years. Contrastingly, the minerals that primarily comprise AVS (mackinawite and greigite) form from their precursors over hours or days. I suggested that the reason for the non-linear AVS/colour correlation was because of a change in the relative proportions of AVS and CRSs with sediment depth. The slope of the fit describing data from a site with a high AVS concentration and low CRSs concentration will be steep because the majority of the change in sediment colour arises from a change in the concentration of AVS minerals. Contrastingly, the slope of the fit describing data from a site with a low AVS concentration and high CRSs concentration will be less steep because a change in sediment colour intensity will be largely from a change in the concentration of CRSs minerals, rather than AVS minerals. Finally, I used this approach investigate temporal changes in the extent of the seafloor area underneath a New Zealand long-line mussel farm of elevated sediment AVS content. Such assessment requires accurate detection of the AVS footprint boundary. I demonstrated how to detect this boundary with sediment profile imagery. I analysed 182 sediment profile images taken along three transects leading from approximately 50 m inside to 200 m outside the long-line mussel farm and found that the mean sediment colour intensity inside the farm boundary was almost 1.5 times lower than that of the sediment away from the farm. Segmented regression analysis of the combined colour intensity data revealed a breakpoint in the trend of increasing grey values with increasing distance from the farm at 56±13 m (± 95% confidence interval of the breakpoint) outside the mussel farm. Mapping of grey value data with ArcMap (ESRI, ArcGIS) indicated that the extent of the AVS footprint is a function of water column depth; organic particles disperse further in a deeper seawater column. I conclude that for soft coastal sediment, the described sampling and data analysis techniques may provide a rapid and reliable supplement to existing benthic surveys that assess environmental effects of marine farms or other organic enrichment sources.

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  • Tama Samoa Stories: Experiences and Perceptions of Identity, Belonging and Future Aspirations at Secondary School

    Rimoni, Fuapepe (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis investigates the experiences of twelve strong, articulate and thoughtful tama Samoa (Samoan boys) through their participation in secondary schools and lives outside the classroom and through the stories of others. The study looked at how the students enacted their identities as Samoans, as learners and as young men who are anticipating the future. The study is premised on the view that Pacific identities are fluid, diverse, multi-dimensional and include a range of different perspectives relating to social class, ethnicity, culture and gender. Such a view of identity as complex is not generally taken into consideration in the literature on educational success and achievement of Pacific students in New Zealand. The study employed a phenomenological qualitative design, using focus groups and semi-structured interviews by talanoa (conversations). As the study involved a group of indigenous tama Samoa, the Samoan fa’afaletui method was used. Participants were a group of twelve tama Samoa in three Wellington secondary schools and their twelve nominated persons. The study found that there are key aspects to making the experiences of tama Samoa positive and successful within the secondary school. These include acknowledging tama Samoa and their multiple identities while attending secondary school; supporting the development of a sense of belonging through everyday interactions with peers and teachers, and affirming the belief by tama Samoa that secondary school socialisation serves to help them make future decisions. This study argues that the experiences of tama Samoa are deeply embedded within wider social, economic and political trends. Indeed, their “voices” are shaped in part by these broader forces that construct and represent them as being historically “disadvantaged” and socio-economically “underserved.” Further, this study advocates for the diverse voices of tama Samoa, along with their experiences, stories, hopes, aspirations and dreams to be brought to light and placed alongside the official accounts of Pacific “disadvantage” to enable more balanced critical discourses taking place. It is hoped that this study will offer further insights into the experiences of tama Samoa in the New Zealand secondary school context, from which valuable knowledge is derived to inform and support schools in improving the New Zealand secondary school experiences of Samoan adolescent boys.

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  • Exploring the use of ICTs in non-profit sector organisations: supporting the third act

    Priyanga De Silva Senapathy, Nishanie (2016)

    Doctoral thesis
    Victoria University of Wellington

    Life after retirement from full-time work is known as the third act of an individual. In New Zealand the third act has become longer, resulting in an ageing population. An implication of population ageing is the need for increased support and services for older people who live within the community. Non-profit sector organisations primarily cater to those that are either beyond the reach of state services or are unable to afford services offered by the commercial sector. This study is guided by the central research question: how can non-profit sector organisations use ICTs to support service provision for older people living within the community? Using Lamb and Kling’s social actor model, adapted to the context of non-profit sector, the research project explores how ICT use is influenced by factors that are investigated under four key dimensions: affiliations, environment, identities and technology. Employing a case research method, it studies ICT use in four human services non-profit sector organisations. The analysis of the case studies revealed how external influences are enacted within organisations. The study presents a framework which explains post-adoptive use in non-profit sector organisations incorporating external factors, the organisational view and social actor behaviours. The findings suggest that client and funder information requirements influence organisations to select one of four responses to external cues. Organisations adopt either a complementary perspective, a competing perspective, a compatible view or a negotiated view. These organisational information perspectives craft social actor behaviours within non-profit organisations. Further, this study found information challenges associated with maintaining complex client requirements. Mobility of the work force, deficiencies in data capture and limitations of existing client information systems constrain information flow in these organisations. As a result analysis of service utilisation data fails to communicate the actual value created within communities. This study has extended the understanding of ICT use in non-profit human services organisations in New Zealand and contributed to knowledge in the development of the social actor model within specific contexts. The original contribution of this study is the three-tier typology of social actor- information roles. The study presents social actor behaviour associated with a primary entity and an information role. Five main social actor- information roles were identified across three tiers and have been mapped against a spectrum of information behaviours associated with each role. When responding to external cues social actors engage in task related behaviours associated with their information roles. By contributing to ICT use practices, this research presents new perspectives on the components of value in organisational processes. Identifying value adding and value communicating information flows, information loss and informal ICT support roles this study presents a detailed analysis of the factors that enhance and constrain ICT use within human services non-profit sector organisations.

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  • A high cadence photometric survey of five southern hemisphere Milky Way globular clusters.

    Walker, Douglas (2016)

    Doctoral thesis
    University of Canterbury Library

    The Milky Way galaxy is surrounded by some 200 compact Globular Clusters (GCs) of stars, containing up to a million stars each. GCs are dynamical test beds for investigating and proving theories of stellar evolution and harbour a wide variety of binary type star systems and variable stars. Variables include RR Lyrae stars and other stellar exotica, such as blue stragglers, cataclysmic variables, and low-mass X-ray binaries. Recently, a potential new class of rapidly pulsating stars, hydrogen-rich subdwarf (sdO) pulsators, has been discovered in the ω Centauri GC. This research employed difference imaging algorithms to produce time-series photometry data from the 10m Southern African Large Telescope (SALT) and the European Southern Observatory 8.2m Very Large Telescope (VLT) and 3.58m New Technology Telescope (NTT) in La Silla, Chile to investigate the GCs: NGC 1904, NGC 2808, NGC 4833, NGC 5139 (ω Centauri), and NGC 6397. The following work was conducted: • a search for new discoveries in eclipsing binaries, contact binaries, BY Draconis stars, cataclysmic variables and other pulsating stars across all clusters; • generation of an updated set of Colour-Magnitude Diagrams (CMDs) to assist in classification of newly discovered variables; and • an analysis of the eclipsing binary stars and other variables. The result of this process was the discovery of 114 variable stars in NGC 5139, 19 of which were recovered from earlier surveys, leaving 95 potential new variable discoveries. This set includes 5 new eclipsing binary systems, 2 new short period EWs, 1 new low mass-ratio EW, 2 blue straggler stars and 2 RR Lyrae light curve shaped variables. For NGC 6397, 4 new variables are classified as BY Draconis stars associated with star spot activity and 1 potential eclipsing binary system was discovered.

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  • The emerging childcare strategy in European Union law : the struggle between care, gender equality and the market.

    Masselot, Annick (2016)

    Doctoral thesis
    University of Canterbury Library

    This thesis explores the European Union’s (EU) emerging engagement with childcare law and policy. It assesses the extent to which the EU has adopted a childcare strategy which responds to the need of caregivers (who are predominantly but not exclusively women), the requirement of gender equality and the well-being of children, whilst also supporting the EU’s economic aims. The institutions of childcare in EU law are analysed respectively from two broad perspectives: the interrelated and complementary provisions relating to childcare services and the rights of caregivers are considered separately based on their different legal bases. Although the building of an EU childcare strategy designed to set minimum common standards around childcare services appears to be relevant to employment and economic growth, this thesis argues that the EU has made little progress in relation to the adoption of such a coordinated strategy. It acknowledges the difficulties of regulating childcare services at EU level because of the lack of clear competence alongside heavily socio-cultural influences and some resistance from the Member States themselves. It shows that the role of the EU is mainly limited to encouraging Member States to adopt (preferably publicly subsidised) available, affordable and quality out-of-home childcare provisions as well as to provide a forum for information sharing. The thesis then moves on to provide a critical perspective on the Barcelona targets and the subsequent policies which, it is demonstrated, have failed to contribute effectively to gender equality and other EU values. It concludes that the EU’s ability to influence childcare regulation is limited to principle setting. Nonetheless, the thesis does establish that the EU actively addresses the rights of caregivers (especially mothers). The thesis notes how the EU has developed these rights along two broad areas - while rights to work-life reconciliation have mainly contributed to supporting the employment of women in the labour market, the Court of Justice of the EU has tied the concept of care to that of citizenship - and how the development of parents’ rights in these areas signifies the EU’s commitment to supporting childcare and the work of caregivers. However it is also clear that the rights to protect and empower caregivers have been patchy, insufficient and, in some areas, legally uncertain.

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  • The Evolution of Evolutionary Explanations of Culture: How and Why Can a Critical Evaluation of Costly Signalling Theory Enhance Our Understanding of Cultural Practices?

    Searfoss, Amy Elizabeth Robertson (2016)

    Doctoral thesis
    Victoria University of Wellington

    In the last two decades, evolutionary explanations of cultural practice have become prevalent within the social sciences and humanities, including religious studies. This thesis is a critical analysis and recension of one of these applications of evolutionary theory to cultural practice. Specifically, I analyse a secondary case study to investigate the explanatory power and politico-ethical considerations that arise from the application of costly signalling theory to Māori tā moko. Utilising primary and secondary source materials, this research was conducted within an interpretivist and inductive qualitative framework with the aim of offering a reflexive critique of the explanatory power that costly signalling theory carries for tā moko and, more broadly, of the illustrative efficacy of evolutionary explanations when applied to indigenous cultural practices. In a critique of the Cisco case study, I identify some of the more general, global deficiencies of evolutionary explanations of culture and explore the rich, indigenous narrative complexes which shape understandings of Māori tā moko. I maintain that the argument for moko as a costly signal, based, in part, upon Māori warfare is a reiteration of mythologised aspects of Māori culture which divorces tā moko from its ontological and epistemological underpinnings. In separating it from its Māori context, the reflexivity of tā moko is denied and Westernised and colonised conceptions of tā moko which etically view Māori cultural practice through a veil of alterity are perpetuated. In response to the concerns the application of costly signalling theory to tā moko generates, I propose an alternative model: transmissive assemblage. Drawing from actor-network theory, indigenous ontological perspectivism, and Kaupapa Māori, the transmissive assemblage model provides a symmetrical and decolonised framework which both challenges and enhances the dominant Western scientific paradigms used to explain indigenous practices. By focussing on the interactions between agents and the associations which circulate between them, rather than on the agents themselves, this integrative model makes an original contribution to scholarship in allowing the emergence of heteroglossia and by providing a balanced platform for indigenous voices and emic perspectives to be represented in the context of Western scientific research. In doing so, I argue that integrative, reflexive, and decolonised approaches to indigenous cultural practice which focus on process, as opposed to agency, enhance the explanatory power of evolutionary explanations by affording indigenous groups the opportunity to assert their own agency within the paradigm of Western science.

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  • Proteins as bulding blocks for biological nanomaterials.

    Ashmead, Helen (2016)

    Doctoral thesis
    University of Canterbury Library

    Within the field of nanoscience there is a growing interest in the use of biological molecules such as proteins, peptides and nucleic acids, to create materials with complex structure and function. These molecules self-assemble to form a huge variety of functional nanoscale structures in biological systems. Through the work of supramolecular chemistry there is now a greater understanding of how to control the assembly of molecules into functional entities. The aim of this thesis is to combine the fields of biology and supramolecular chemistry to increase the repertoire of available protein building blocks for use in bionanotechnology. Three proteins have been selected due to their ability to self assemble in nature, Lsr2, the Nterminal domain of Lsr2 (Nterm-Lsr2) and human peroxiredoxin 3 (H?Prx3). Lsr2 is a small DNA binding protein that has the innate ability to self-assemble in vivo via a number of routes. This makes it an ideal candidate as a biological building block for forming nanomaterials in vitro. The truncated version of Lsr2 (Nterm-Lsr2) oligomerises into linear chains via anti-parallel β-sheet formation between the extended N-termini of neighbouring dimers. This process was facilitated in vitro using low concentrations of trypsin which removed three N-terminal residues, Met¹, Ala² and Lys³, allowing an inter-dimer anti-parallel β-sheet to form. Using trypsin to initiate assembly led to unwanted proteolysis at additional lysine and arginine residues within the polypeptide chain. A novel and more controlled method of initiating assembly was developed by replacing three N-terminal residues with an enteropeptidase recognition site. Enteropeptidase cleaves specifically at Lys⁴ leaving an identical sequence to the native protein when treated with trypsin but without additional fractionation. This allows the formation of an ordered network of “spaghetti-like” fibres. The structures alternate between a tetramer and high molecular weight oligomers in response to variations in pH. Further control is exerted over the system by exploiting the open symmetry of the assemblies. Increasing and decreasing the protein tecton concentration leads to the formation of larger and smaller structures respectively. Wild type H?Prx3 has been shown to assemble into one dimensional tubes at acidic pH (pH 4.2). By incorporating the N-terminal histidine tag and linker sequence (H?Prx3-6his) into the current assembly system, a number of novel oligomerisation routes were developed. The presence of the tag and linker stabilises the dodecameric toroid leaving an ideal tecton from which higher ordered structures can form. The increased pH sensitivity of H?Prx3-6his allows the formation of tubes at pH 7.4. The size of the assembly was further controlled by small changes in pH, with the tube length increasing with decreasing pH values. It is proposed that electrostatic interactions at the ring interface are driving the assembly. Increasing the salt concentration, thereby disrupting these electrostatic interactions, caused the tubes to dissociate into single rings. Increasing the histidine content within the tag led to the formation of longer tubes, suggesting that the presence of the non-native histidine residues is the origin of the pH sensitivity. The metal-binding imidazole side groups of the histidine tag were also utilised to stabilise stacks of H?Prx3-6his through coordination to Ni²⁺. The switch from high molecular weight stacks to low molecular weight rings was achieved with the addition of chelating agents to the solution. Throughout this study, novel protein building blocks have been developed that assemble and disassemble in a controllable manner in response to variations in environmental conditions. The assembly system of an existing protein tecton (H?Prx3-WT) has been enhanced, creating a protein building block that associates within the physiological pH range. These new routes towards controlled protein oligomerisation could be utilised in future work to form protein nanomaterials for specific functions.

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  • The relationship between enterprise resource planning (ERP) implementation and intellectual capital under the moderating effect of organizational learning capability

    Nguyen, Quang (2016)

    Doctoral thesis
    Victoria University of Wellington

    Although Enterprise Resource Planning (ERP) systems alone are not the source of competitive advantage, they may do this indirectly through enhancing or supplementing the organization’s other strategic resources. Studies on ERP have not explicitly examined the interactions of ERP systems with other organizational capabilities to determine how investment in ERP systems can be leveraged into the creation of strategic resources of organizations. Further, ERP systems are large and complex, and the degree to which they are implemented throughout an organization can vary – this is described as the ERP scope. The scope of ERP implementation is believed to influence the degree of its effects on an organization. Relying on the literature on ERP effects, business value of information technology (IT) and the notion that organizations are learning systems which utilize their knowledge to create value and to accumulate further knowledge, this study examines the influence of the scope of ERP implementation on a strategic resource of organizations, namely intellectual capital, under the moderating effect of organizational learning capability. This study develops a research model to show the influence of the three dimensions of ERP implementation scope (breadth, depth, and magnitude) on intellectual capital and simultaneously the influence of organizational learning capability on these base relationships. The hypothesized relationships among variables are evaluated by a data set of 226 responses collected from manufacturing firms in Vietnam. With the support of SmartPLS version 2.0, the structural equation model is evaluated using the techniques of multiple regression analysis, and the moderation effects are analyzed using group comparison and product term approaches. The findings provide support for the hypotheses. The three dimensions of ERP implementation show a positive impact on intellectual capital. Organizational learning capability more or less moderates the relationship between ERP implementation scope and intellectual capital. As a result of the group comparison approach for moderation analysis, firms with a low level of learning capability are likely to have no effect of ERP implementation on intellectual capital. However, in the group with a high level of learning capability the breadth and magnitude of ERP implementation have a positive effect on intellectual capital. By using the product term approach, only the magnitude of ERP implementation shows an interaction effect with organizational learning capability on intellectual capital. The breadth and depth of ERP implementation appear to have minimal interaction with organizational learning capability. The results inform the literature on the business value of IT by demonstrating that an ERP system can become a strategic asset as its implementation has a positive effect on intellectual capital especially with the presence of a firm’s learning capability. Additionally, the research reveals another ERP effect (e.g. the effect on the intellectual capital of organizations) that complements the understanding of ERP effects that have been identified in prior studies. The findings practically contribute to managerial knowledge by showing that ERP implementation should not be considered in isolation, but rather organizations should build a substantial level of learning capability to fully obtain the positive effect of ERP implementation on intellectual capital.

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  • Feverish: Self-Induced Fever and the Creative Mind

    Fenster, Giovanna (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis is a hybrid work that combines the critical and creative components of the Creative Writing PhD in a novel, Feverish. It includes notes, an afterword, and a full bibliography. Feverish is a novel narrated by Gigi, a writer who wishes to induce a fever in herself. The thesis aims to present more than a fictional account of a quest for fever. It aims, rather to travel with the mind of the protagonist. Gigi is not exclusively engaged in quest-related transactions in her present. Her interest in fever moves her to consider events from her past and her upbringing in Apartheid South Africa. It reminds her of a teenaged fascination with brain fever in Wuthering Heights. It prompts her to research fever-related aspects of psychiatric history and Jewish history. It drives her to research the law on consent to self-harm. As Gigi’s interest in fever leads her to these and other topics, so the thesis follows her, so the form adapts. In both its form and its content, Feverish presents a view into a mind. It provides glimpses of the events that shaped the mind. It describes where the mind goes when in the single-minded grip of a quasi-fever. The novel contains strands of theory, memoir, creative non-fiction, ficto-criticism. These different forms are layered upon each other. At times they make way for each other. At times they assert themselves over each other. In the notes at the end of the novel, the theoretical strand is at its most assertive. The notes present Gigi’s mind at its most critical, when it is directed at supporting the theoretical aspects of her quest. They support Gigi’s accounts of her research by providing additional information and citations. The narrative arc is provided by a chronological account of the days Gigi devotes to her fever quest. What follows here is a skeleton account of the novel. Feverish opens with a conversation between Gigi and a friend. This conversation spurs Gigi to explore brave artistic acts, and to the decision to induce a fever in herself. She remembers childhood holidays. Books, and in particular the nineteenth-century children’s literature that featured fever, are the focal point of these memories. Gigi recalls one particular holiday, taken at a time when a friend of hers, Simon, was just starting to show signs of mental illness. Gigi starts planning her fever. She writes a ‘fever manifesto’. But she worries her siblings will think her insane. She remembers Alberto, a schizophrenic patient of her father’s for whom recovery had, according to his parents, been foretold. Gigi’s husband, son and daughter are introduced. The family has a dinnertime discussion on bravery, anti-Semitism and terrorist attacks. Gigi starts researching fever. She imagines a conversation between her deceased father and Simon about Julius Wagner-Jauregg, a Nobel Prize-winning psychiatrist who induced malaria in patients suffering from neurosyphilis. Gigi’s father and Simon discuss an historic ‘showdown’ between Wagner-Jauregg and Freud. Gigi remembers Steve Biko’s death and her father’s aggressive response to a guest who supported Biko’s doctors. Gigi is distracted from her research into fever by her son, who is vacuuming his room. She tells him a friend of hers is thinking of inducing a fever in herself. He explains the difference between fever and hyperthermia. Gigi realises that, to induce true fever, she will have to become ill. This prompts memories of the meningitis her brother suffered from as a child. Gigi uses Fildes’s famous painting, The Doctor as the starting point in an argument for a universal desire to be watched over in illness. Gigi imagines a conversation she feels she ought to have had with her father, about (mental) illness in Wuthering Heights. They test the characters against each one’s ability to empathise with Catherine’s ‘brain fever’. Their discussion of Nelly’s status as servant prompts in Gigi the memory of a shameful childhood act. A visit from a friend from law school prompts Gigi to research the law that could impact on her quest. She reviews case law relating to consent to self-harm, personal autonomy, and the boundaries of criminal law. Her research is interrupted by domestic concerns: her cat kills an endangered bird; her son writes a fever-related essay for school; she accompanies a friend in looking for her errant daughter. At the end of the novel Gigi and her family confront a crisis. It becomes clear that Gigi is not the only family member unsettled by fever.

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  • Interference Alignment and Cancellation in Wireless Communication Systems

    Ustok, Refik (2016)

    Doctoral thesis
    Victoria University of Wellington

    The Shannon capacity of wireless networks has a fundamental importance for network information theory. This area has recently seen remarkable progress on a variety of problems including the capacity of interference networks, X networks, cellular networks, cooperative communication networks and cognitive radio networks. While each communication scenario has its own characteristics, a common reason of these recent developments is the new idea of interference alignment. The idea of interference alignment is to consolidate the interference into smaller dimensions of signal space at each receiver and use the remaining dimensions to transmit the desired signals without any interference. However, perfect alignment of interference requires certain assumptions, such as perfect channel state information at transmitter and receiver, perfect synchronization and feedback. Today’s wireless communication systems, on the other and, do not encounter such ideal conditions. In this thesis, we cover a breadth of topics of interference alignment and cancellation schemes in wireless communication systems such as multihop relay networks, multicell networks as well as cooperation and optimisation in such systems. Our main contributions in this thesis can be summarised as follows: • We derive analytical expressions for an interference alignment scheme in a multihop relay network with imperfect channel state information, and investigate the impact of interference on such systems where interference could accumulate due to the misalignment at each hop. • We also address the dimensionality problem in larger wireless communication systems such as multi-cellular systems. We propose precoding schemes based on maximising signal power over interference and noise. We show that these precoding vectors would dramatically improve the rates for multi-user cellular networks in both uplink and downlink, without requiring an excessive number of dimensions. Furthermore, we investigate how to improve the receivers which can mitigate interference more efficiently. • We also propose partial cooperation in an interference alignment and cancellation scheme. This enables us to assess the merits of varying mixture of cooperative and non-cooperative users and the gains achievable while reducing the overhead of channel estimation. In addition to this, we analytically derive expressions for the additional interference caused by imperfect channel estimation in such cooperative systems. We also show the impact of imperfect channel estimation on cooperation gains. • Furthermore, we propose jointly optimisation of interference alignment and cancellation for multi-user multi-cellular networks in both uplink and downlink. We find the optimum set of transceivers which minimise the mean square error at each base station. We demonstrate that optimised transceivers can outperform existing interference alignment and cancellation schemes. • Finally, we consider power adaptation and user selection schemes. The simulation results indicate that user selection and power adaptation techniques based on estimated rates can improve the overall system performance significantly.

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  • The doctrine of frustration, commercial leases and the Canterbury earthquakes

    Collins, Toni Leah (2016)

    Doctoral thesis
    University of Canterbury Library

    The Canterbury earthquakes in 2010 and 2011 had a significant impact on landlords and tenants of commercial buildings in the city of Christchurch. The devastation wrought on the city was so severe that in an unprecedented response to this disaster a cordon was erected around the central business district for nearly two and half years while demolition, repairs and rebuilding took place. Despite the destruction, not all buildings were damaged. Many could have been occupied and used immediately if they had not been within the cordoned area. Others had only minor damage but repairs to them could not be commenced, let alone completed, owing to restrictions on access caused by the cordon. Tenants were faced with a major problem in that they could not access their buildings and it was likely to be a long time before they would be allowed access again. The other problem was uncertainty about the legal position as neither the standard form leases in use, nor any statute, provided for issues arising from an inaccessible building. The parties were therefore uncertain about their legal rights and obligations in this situation. Landlords and tenants were unsure whether tenants were required to pay rent for a building that could not be accessed or whether they could terminate their leases on the basis that the building was inaccessible. This thesis looks at whether the common law doctrine of frustration could apply to leases in these circumstances, where the lease had made no provision. It analyses the history of the doctrine and how it applies to a lease, the standard form leases in use at the time of the earthquakes and the unexpected and extraordinary nature of the earthquakes. It then reports on the findings of the qualitative empirical research undertaken to look at the experiences of landlords and tenants after the earthquakes. It is argued that the circumstances of landlords and tenants met the test for the doctrine of frustration. Therefore, the doctrine could have applied to leases to enable the parties to terminate them. It concludes with a suggestion for reform in the form of a new Act to govern the special relationship between commercial landlords and tenants, similar to legislation already in place covering other types of relationships like those in residential tenancies and employment. Such legislation could provide dispute resolution services to enable landlords and tenants to have access to justice to determine their legal rights at all times, and in particular, in times of crisis.

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  • To react or deliberate? : the utility of New Zealand's counterinsurgent communication during the international campaign against terrorism.

    Rout, Matthew William (2016)

    Doctoral thesis
    University of Canterbury Library

    This thesis examines New Zealand’s counterinsurgent communication – that is, its press releases that focus on the ‘war on terror’ – from 9/11 for a period of ten years. The aim is to understand the effectiveness of a counterinsurgent’s press releases in an era where the number of key audiences in a counterinsurgency has grown and targeting any of them is near-impossible, with a particular focus on how the different requirements of each key audience compromises the utility of communication for others. The thesis identifies two narratives present in New Zealand’s counterinsurgent communication: the ‘deliberative’ and ‘reactive’. The former is understood to be honed by technocrats over time in a measured fashion – it is deliberated upon – while the latter is quickly crafted by politicians during the emotive shockwave that follows an attack – it is a reaction. It also proposes that these two narratives have differing functions, the deliberative serves to justify the counterinsurgent’s cause and legitimise them as an actor to both their own support population and the insurgent support population while the reactive helps control and direct the negative emotions generated by a terrorist attack within the counterinsurgent’s support audience, mobilises domestic support for action and also reinforces ingroup bonds with international allies. Using population-centric counterinsurgency theory combined with insights on insurgent’s strategies and the characteristics of counterinsurgents, it outlines five key opposing qualities that define these narratives. The thesis creates an analytical framework that fuses framing theory with these five opposing qualities and extracts the necessary data from a decade’s worth New Zealand government press releases given by the Prime Minster, Foreign Affairs Minister and Minister of Defence using content analysis. Each deliberative and reactive framing task is examined using a combination of qualitative and quantitative assessments to provide a comprehensive understanding of the utility of these two narratives with regard to three key audiences: the insurgent support population, the domestic audience and the allied audience. The findings suggest that these two different narratives to some degree, compromised the overall utility of New Zealand’s communication, specifically the justness of New Zealand’s cause and, consequently, their legitimacy as a counterinsurgent. Furthermore, the thesis argues that the reactive was of limited utility for the insurgent support audience, mixed utility for the domestic audience and utility for the allied audience, while the deliberative narrative was of utility for the insurgent support audience, mixed utility for the domestic audience and limited utility for allied audience. It also concludes that the reactive was used more frequently following attacks, to a wider international rather than domestic audience and its use declined over time while the deliberative was used more for the domestic audience and was used more consistently over the period than the reactive. Finally, it warns that while democracies may be suited to fighting conventional conflicts, they are not so well placed with regard to communicating in counterinsurgencies, particularly when they have low direct stakes and high indirect stakes.

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