89,525 results

  • Intertidal foraminifera of the Avon-Heathcote Estuary; response to coseismic deformation and potential to record local historic events

    Vettoretti, Gina Josephine (2014)

    Masters thesis
    University of Canterbury Library

    The Avon-Heathcote Estuary, located in Christchurch, New Zealand, experienced coseismic deformation as a result of the February 22nd 2011 Christchurch Earthquake. The deformation is reflected as subsidence in the northern area and uplift in the southern area of the Estuary, in addition to sand volcanoes which forced up sediment throughout the floor of the Estuary altering estuary bed height and tidal flow. The first part of the research involved quantifying the change in the modern benthic foraminifera distribution as a result of the coseismic deformation caused by the February 22nd 2011 earthquake. By analysing the taxa present immediately post deformation and then the taxa present 2 years post deformation a comparison of the benthic foraminifera distribution can be made of the pre and post deformation. Both the northern and the southern areas of the Estuary were sampled to establish whether foraminifera faunas migrated landward or seaward as a result of subsidence and uplift experienced in different areas. There was no statistical change in overall species distribution in the two year time period since the coseismic deformation occurred, however, there were some noticeable changes in foraminifera distribution at BSNS-Z3 showing a landward migration of taxa. The changes that were predicted to occur as a result of the deformation of the Estuary are taking longer than expected to show up in the foraminiferal record and a longer time period is needed to establish these changes. The second stage involved establishing the modern distribution of foraminifera at Settlers Reserve in the southern area of the Avon-Heathcote Estuary by detailed sampling along a 160 m transect. Foraminifera are sensitive to environmental parameters, tidal height, grainsize, pH and salinity were recorded to evaluate the effect these parameters have on distribution. Bray-Curtis two-way cluster analysis was primarily used to assess the distribution pattern of foraminifera. The modern foraminifera distribution is comparable to that of the modern day New Zealand brackish-water benthic foraminifera distribution and includes species not yet found in other studies of the Avon-Heathcote Estuary. Differences in sampling techniques and the restricted intertidal marshland area where the transect samples were collected account for some of the differences seen between this model and past foraminifera studies. xiii The final stage involved sampling a 2.20 m core collected from Settlers Reserve and using the modern foraminiferal distribution to establish a foraminiferal history of Settlers Reserve. As foraminifera are sensitive to tidal height they may record past coseismic deformation events and the core was used to ascertain whether record of past coseismic deformation is preserved in Settlers Reserve sediments. Sampling the core for foraminifera, grainsize, trace metals and carbon material helped to build a story of estuary development. Using the modern foraminiferal distribution and the tidal height information collected, a down core model of past tidal heights was established to determine past rates of change. Foraminifera are not well preserved throughout the core, however, a sudden relative rise in sea level is recorded between 0.25 m and 0.85 m. Using trace metal and isotope analysis to develop an age profile, this sea level rise is interpreted to record coseismic subsidence associated with a palaeoseismic event in the early 1900’s. Overall, although the Avon-Heathcote Estuary experienced clear coseismic deformation as a result of the 22nd of February 2011 earthquake, modern changes in foraminiferal distribution cannot yet be tracked, however, past seismic deformation is identified in a core. The modern transect describes the foraminifera distribution which identifies species that have not been identified in the Avon-Heathcote Estuary before. This thesis enhances the current knowledge of the Avon-Heathcote Estuary and is a baseline for future studies.

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  • Education and the boarding school novel : examining the work of José Régio

    Santos, Filipe D. Saavedra (2014)

    Doctoral thesis
    University of Canterbury Library

    This thesis is centred on the work of Portuguese writer José Régio (1901-1969). He was a teacher-writer and, arguably, the most philosophical of Portuguese school novel authors. In his novel ‘A Drop of Blood’ (1945), Régio shows interest in the formation of the artist as the special object of education – the ‘marked man’ –, whose sensitivity distances him irremediably from the crowd. He adopted the radical individualism of Nietzsche not in order to be ‘for’ or ‘against’ this or that schooling model but to exemplify the perpetual clash, inherent in mankind, between the individual and the group, the artist and the non-artistic person, the young and the adult, the son and the father and the self and the world. Published Proquest ebook version: http://ebookcentral.proquest.com/lib/canterbury/detail.action?docID=4799556 (UC Staff and Student use only)

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  • A multi-criteria approach to the evaluation of food safety interventions.

    Dunn, Alexander Hiram (2015)

    Doctoral thesis
    University of Canterbury Library

    New Zealand faces a range of food safety hazards. Microbial hazards alone were estimated to cause over 2,000 years of lost healthy life in 2011 (Cressey, 2012) and $62m in medical costs and lost productivity in 2009 (Gadiel & Abelson, 2010). Chemical hazards are thought to be well managed through existing controls (Vannoort & Thomson, 2009) whereas microbial hazards are considered harder to control, primarily due to their ability to reproduce along the food production chain. Microbial hazards are thought to cause the majority of acute foodborne gastroenteritis. This research reviewed food safety literature and official documentation, and conducted 55 interviews, mostly with food safety experts from different stakeholder groups, to examine the food safety decision-making environment in New Zealand. This research explores the concept of the ‘stakeholder’ in the context of food safety decision-making and proposes an inclusive ‘stakeholder’ definition as any group which is able to affect, or be affected by, the decision-making process. Utilising this definition, and guided by interviews, New Zealand stakeholders in food safety decision-making were identified and classified as follows: •Regulators •Public health authorities •Food safety scientists/academics •Consumers •Māori •Food Businesses (further classified as): o Farmers o Processors o Food retailers o Exporters Interviews with stakeholders from these groups highlighted twelve criteria as being relevant to multiple groups during food safety intervention evaluation: •Effectiveness •Financial cost •Market Access •Consumer Perceptions •Ease of Implementation •Quality or Suitability •Quality of Science •Equity of Costs •Equity of Benefits •Workplace Safety •Cultural Impact •Animal Welfare There are a number of different ways to measure or assess performance on these criteria. Some are able to be quantitatively measured, while others may require the use of value judgements. This thesis used the Disability-Adjusted Life Year (DALY) metric for quantifying effectiveness during the testing of different MCDA models. This thesis reviews the MCDA process and the food safety specific MCDA literature. There are different ways of conducting MCDA. In particular, there are a large number of models available for the aggregation phase; the process of converting model inputs, in the form of criteria scores and weights, into model recommendations. This thesis has described and reviewed the main classes of model. The literature review and interview process guided the construction and testing of three classes of MCDA model; the Weighted Sum, Analytic Hierarchy Process (AHP) and PROMETHEE models. These models were selected due to their having different characteristics and degrees of complexity, as well as their popularity in the food safety and Health Technology Assessment (HTA) literature. Models were tested on the problem of selecting the most appropriate intervention to address the historic Campylobacter in poultry problem in New Zealand during the mid-2000s. Experimentation was conducted on these models to explore how different configurations utilise data and produce model outputs. This experimentation included: •Varying the format of input data •Exploring the effects of including/excluding criteria •Methods for sensitivity analysis •Exploring how data inputs and outputs can be elicited and presented using visual tools • Creating and using hybrid MCDA models The results of this testing are a key output of this thesis and provide insight into how such models might be used in food safety decision-making. The conclusions reached throughout this research phase can be classified into one of two broad groups: •Those relating to MCDA as a holistic process/methodology for decision-making •Those relating to the specific models and mathematical procedures for generating numerical inputs and outputs This thesis demonstrates that food-safety decision-making is a true multi-criteria, multi-stakeholder problem. The different stakeholders in food-safety decision-making do not always agree on the value and importance of the attributes used to evaluate competing intervention schemes. MCDA is well suited to cope with such complexity as it provides a structured methodology for the systematic and explicit identification, recording and aggregation of qualitative and quantitative information, gathered from a number of different sources, with the output able to serve as a basis for decision-making. The MCDA models studied in this thesis range from models that are simple and quick to construct and use, to more time consuming models with sophisticated algorithms. The type of model used for MCDA, the way these models are configured and the way inputs are generated or elicited can have a significant impact on the results of an analysis. This thesis has identified a number of key methodological considerations for those looking to employ one of the many available MCDA models. These considerations include: •Whether a model can accommodate the type and format of input data •The desired degree of compensation between criteria (i.e. full, partial or no compensation) •Whether the goal of an analysis is the identification of a ‘best’ option(s), or the facilitation of discussion, and communication of data •The degree of transparency required from a model and whether an easily understood audit trail is desired/required •The desired output of a model (e.g. complete or partial ranking). This thesis has also identified a number of practical considerations when selecting which model to use in food safety decision-making. These include: •The amount of time and energy required of stakeholders in the generation of data inputs (elicitation burden) •The degree of training required for participants •How data inputs are to be elicited and aggregated in different group decision-making environments •The availability of MCDA software for assisting an analysis Considering the above points will assist users in selecting a suitable MCDA model that meets their requirements and constraints. This thesis provides original and practical knowledge to assist groups or individuals looking to employ MCDA in the context of food-safety intervention decision-making. This research could also serve as a guide for those looking to evaluate a different selection of MCDA models.

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  • Morphosyntactic development of typically- and atypically-developing Bangla-speaking children.

    Sultana, Asifa (2015)

    Doctoral thesis
    University of Canterbury Library

    Aims: Verb morphology, arguably, is identified as an area of exceptional challenge for the language development of both young typically-developing children, and children with language difficulties (Leonard, 2014a; Rice & Wexler, 2001). The developmental patterns of verb acquisition are found to be strongly governed by the typological properties of the ambient language; often language errors found in fusional languages (e.g. English and German) are significantly different from those found in agglutinative languages (e.g. Turkish and Tamil) (cf. Phillips, 2010). Therefore, the purpose of the study was to explore the developmental trends in the acquisition of verb morphology in Bangla, a language with agglutinative features. The first objective was to examine the morphosyntactic development of typically-developing (TD) Bangla-speaking children with regard to three verb forms, namely the Present Simple, the Present Progressive and the Past Progressive. A second objective was to examine the development of the three verb forms among a group of children with language impairment (LI). Rationale: Since Bangla is spoken by a large population, the acquisition data of Bangla represents a significant number of people, and the findings from the acquisition studies, when considered for intervention purposes, serve a considerably large population. Also, given that the normative data of language acquisition is unavailable for Bangla which leads to the absence of a language-specific assessment and intervention for LI children, the present study is expected to have importance for Bangla-speaking contexts. Method: Before the main study commenced, a pilot study was conducted with 19 Bangla-speaking TD children aged between two and four (years) in order to explore the developmental characteristics of the verb forms and to evaluate the research instruments identified for the actual study. The main study included 70 TD children between 1;11 and 4;3 years who were recruited from six daycare centres of Dhaka, Bangladesh. The children participated in three elicitation tasks, each to elicit one verb form, and a 20-minute play session that yielded a spontaneous language sample from each child. The researcher scored children’s performances on the three tasks, and transcribed the language samples using transcription software (Systematic Analysis of Language Transcripts). The elicitation tasks were used to determine children’s mastery of the forms, whereas the language samples were used to calculate a set of language measures associated with morphological development. The study also included a group of nine children with LI between 3;11 and 9;4 years who participated in the same set of tasks as the TD children. These children were recruited from a special school in Dhaka. Findings: The results revealed that, for both TD and LI children, the Present Simple form was acquired with highest accuracy which was followed by the scores in the Present Progressive and the Past Progressive forms respectively. The error patterns indicated a qualitative progress even in children’s errors, which was consistent with the accuracy rates of the target forms. Based on the TD children’s performance on the three tasks, a developmental sequence for the three Bangla verb forms was proposed. Results also identified that Mean length of Utterance (MLU) did not have stronger associations with the tasks scores than did Age. Among the determinants tested, Bound Morpheme Type (BMT) was identified to have the strongest associations with the task scores. Analyses of the data from the LI children revealed a significant difference between the TD and the LI children on all three tasks and the other language measures. When compared against the proposed developmental stages, the children within the LI group were found to different in terms of their morphosyntactic capacities. A sub-group of LI children also did not conform to any stages of typical development. Conclusions: Results of the present study offer directions for future investigations in a wide range of areas of Bangla morphosyntax that need to be examined with both TD and LI children. Moreover, factors associated with language development that the present study did not examine (e.g. the role of input) also need to be addressed in future studies. Above all, there is a strong need for ongoing investigations in order to identify a comprehensive picture of morphosyntactic development of Bangla-speaking TD children, which can then lead to the assessment of a range of language impairments in Bangla.

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  • A spatial analysis of dengue fever and an analysis of dengue control strategies in Jeddah City, Saudi Arabia

    Alkhaldy, Ibrahim (2014)

    Doctoral thesis
    University of Canterbury Library

    Dengue fever poses a constant serious risk and continues to be a major public health threat in Saudi Arabia, particularly in the city of Jeddah where, since 2006, despite formally introduced Control Strategies, there has been a significant increase in the number of cases. International literature suggests that a range of variables can influence the persistence of dengue, including climatic conditions, the quality of the urban environment, socioeconomic status and control strategies. The overall aims of this research are to understand neighbourhood influences on the pattern of dengue fever across Jeddah City and to make a preliminary determination of the enabling factors for, and barriers to, the effective implementation of the Control Strategies for dengue fever in Jeddah City. A mixed methods research design using quantitative and qualitative data was used. Quantitative data were obtained from administrative sources for dengue fever cases and some of the spatial and temporal variables associated with them, but new variables were created for neighbourhood status and the presence of surface water. Qualitative data are drawn from key informant interviews with 15 people who were, or who had been, working on dengue fever Control Strategies. A qualitative descriptive analysis was based on pre- determined and emergent themes. The spatial and temporal analysis of the variables related to dengue fever in Jeddah City neighbourhoods revealed that neighbourhood status has a direct relationship with dengue fever cases, which is mediated through population density and the presence of non- Saudi immigrants. While there was no relationship with the presence of swamps, seasonal variations in the incidence of dengue were most pronounced in neighbourhoods of low socioeconomic status. The qualitative review of dengue Control Strategies indicated five themes: (1) workforce characteristics and capability, (2) knowledge about dengue fever in Saudi Arabia and Jeddah City, (3) operational strategies for dengue fever control in Jeddah City, (4) the progress of implementation, and (5) overall view of the Government strategies in Jeddah City. This analysis found that the Strategies were well regarded but that aspects of implementation were not always effective. Nevertheless, both quantitative and qualitative results showed the persistence dengue fever problems in Jeddah City neighbourhoods and suggested how cases might be controlled. The number of dengue fever cases in Jeddah City neighbourhoods could continue to rise if the direct and indirect variables affecting dengue fever at the neighbourhood level are not well controlled. Careful attention to the further monitoring of patterns of dengue and specific neighbourhood Control Strategies are recommended, and established Control Strategies need to be implemented as designed. Nonetheless, there is still a need to develop new approaches that can examine and address neighbourhood level issues of dengue fever control.

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  • The Influence of Music Congruence and Message Complexity on the Response of Consumers to Advertisements

    Seneviratne, Buddhakoralalage Leelanga Dananjaya (2015)

    Doctoral thesis
    University of Canterbury Library

    The overall aim of this study was to examine how the characteristics of two salient stimuli -music and message- of an audio advertisement influence the psychological state of consumers and how such a state subsequently determines their cognitive and affective responses to the advertisement. In achieving this aim, this study was guided by a combination of two cognitive resource utilisation theories, Limited Capacity Model of Motivated Mediated Message Processing (Lang, 2000) and Resource-Matching Hypothesis (Anand & Sternthal, 1989). In particular building upon inconsistency and load theories, this study proposed that certain stimulus characteristics prompted certain states of a consumer’s cognition. These two stimulus characteristics were the congruence of musical stimulus and the complexity of the message stimulus. The model then predicted the potential effect of these characteristics on certain psychological states (Psychological Discomfort and Cognitive Load) leading to affective (Attitude towards Advertisement) and cognitive (encoding, storage, and retention) responses. To empirically examine this model, an online experiment (using a 2 x 2 between-subject x 2 with-in subject mix design) was conducted, in which a mixed sample of 284 subjects was exposed to a set of audio advertisements especially designed for this study. Unfamiliar music in conjunction with a fictitious brand was used and the exposure level was maintained at low. ANCOVA, MANCOVA, two-stage hierarchical regression analysis, and Repeated-measures MANCOVA were administered to test the hypotheses presented in the conceptual model. Among major findings were that the multiple informational structures in a complex message positively influenced cognitive load, while congruent music was capable of attenuating the level of cognitive load. Incongruent music, on the other hand, was capable of generating a dissonance state experienced as psychological discomfort that in turn increased the level of cognitive load as a result of listener’s trying to resolve such a state. Both dissonance and cognitive load negatively influenced attitude towards advertisements, and the affect primacy of attitude formation appeared to be more applicable. Though high cognitive load clearly undermines encoding, storage, and retrieval processes, no evidence was found to support the Resource-matching Hypothesis. Furthermore, the findings suggested that the cognitive load offset by the congruent music would increase advertisement effectiveness by enabling its message to carry more information and by generating more favourable attitudes.

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  • The Function of TAR1 and the Evolution of the Retrograde Response

    Walker, Mark (2015)

    Masters thesis
    University of Canterbury Library

    TAR1 is a protein coding gene situated antisense to the 25S rRNA in S. cerevisiae. Tar1p is localized to the mitochondrial inner membrane, and expression is enhanced under conditions of respiratory dysfunction. One common cause of respiratory dysfunction in S. cerevisiae are selfish mitochondrial mutants known as ρ- mitotypes. ρ- mitotypes exhibit drive within the cell following sexual reproduction ; outcompeting host cells and inducing respiratory dysfunction. Respiratory dysfunction activates the Retrograde Response, which involves the expression of genes to compensate for loss of anabolic activity that accompanies respiratory dysfunction. The Retrograde Response also leads to the formation of lifespan shortening Extrachromosomal rDNA circles. Amplification of rDNA circles has the effect of increasing TAR1 at the same time as lifting transcription repression. This observation led to the hypothesis that the formation of rDNA circles was a positive effect of the Retrograde Response, and that TAR1 may serve to ameoleriate the spread of respiratory incompetent mitochondria following sexual reproduction. In this thesis, experiments are conducted that show that TAR1 does suppress the drive of selfish mitochondrial mutants. Additional bioinformatic analyses show that the Retrograde Response may be a recent adaption to selfish mitochondrial mutants.

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  • The use of head mounted displays (HMDs) in high angle climbing : implications for the application of wearable computers to emergency response work.

    Woodham, Alexander, Timothy (2015)

    Masters thesis
    University of Canterbury Library

    As wearable computers become more ubiquitous in society and work environments, there are concerns that their use could be negatively impactful in some settings. Previous research indicates that mobile phone and wearable computer use can impair walking and driving performance, but as these technologies are adopted into hazardous work environments it is less clear what the impact will be. The current research investigated the effects that head mounted display use has on high angle climbing, a task representative of the extreme physical demands of some hazardous occupations (such as firefighting or search and rescue work). We explored the effect that introducing a secondary word reading and later recall task has on both climbing performance (holds per meter climbed and distance covered), and word reading and recall (dual-task effects). We found a decrease in both climbing performance and word recall under dual task conditions. Further, we examined participant climbing motion around word presentation and non-word presentation times during the climbing traverse. We found that participants slowed around word presentations, relative to periods without word presentation. Finally, we compared our results to those found in previous research using similar dual-tasking paradigms. These comparisons indicated that physical tasks may be more detrimental to word recall than seated tasks, and that visual stimuli might hinder climbing performance more than audible stimuli. This research has important theoretical implications for the dual-tasking paradigm, as well at important practical implications for emergency response operations and other hazardous working environments.

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  • Enrichment facilitates recovery of spatial memory but not retrosplenial immediate early gene hypoactivation after anterior thalamic lesions

    Mercer, Stephanie Ann (2015)

    Masters thesis
    University of Canterbury Library

    The anterior thalamus exists within an ‘extended hippocampal memory system’ and has extensive reciprocal connectivity with regions known to support spatial memory function such as the retrosplenial cortex (RSC). Damage to the anterior thalamic nuclei (ATN) in humans as a result of injury or neurodegenerative disease is associated with severe anterograde amnesia that is not therapeutically manageable. Rat models of ATN lesions have provided potential avenues of treatment through environmental enrichment, to ameliorate some of the lesion-induced deficits. Previously, behavioural recovery after enrichment did not accompany recovery of the striking immediate early gene (IEG) hypoactivation in the RSC found after ATN lesions, but the tasks used may not have been sensitive to RSC function. A modified radial arm maze (RAM) task sensitive to RSC lesions was therefore used to determine whether behavioural recovery was associated with improved expression of zif268, an IEG associated with spatial memory. Initially, water maze spatial tasks were used to establish spatial memory deficits prior to enrichment and to assess memory during the period of continuous enrichment and when overnight enrichment was continued thereafter. There was little or no evidence of recovery from substantial impairments in water maze memory tasks in rats with ATN lesions. However, subsequent testing on the RAM revealed clear, albeit partial, recovery of spatial memory in the enriched rats with ATN lesions. Nonetheless, levels of zif268 expression in the superficial layers of the granular RSC remained at the same level of hypoactivity of standard-housed ATN rats; instead, there was some evidence of recovered CA1 zif268 expression. ATN lesions were also associated with reduced cell counts in the mammillary bodies, which were also not recovered in enriched rats. These findings suggest that IEG expression in the RSC may not always be a critical biomarker for spatial memory function in rats.

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  • Hydrodynamics and chemistry of silica scale formation in hydrogeothermal systems.

    Kokhanenko, Pavlo (2015)

    Doctoral thesis
    University of Canterbury Library

    The extraction of geothermal heat can cause precipitation of the minerals dissolved in geothermal fluid. Their deposition on the walls of wells and above-ground plant and in pores near reinjection wells, also known as mineral scaling, is one of the main obstacles to increasing the effectiveness of utilization of the limited geothermal resources. If not controlled properly it can result in accumulation of a significant amount of scale which obstructs pipes and reinjection wells and reduces the efficacy of heat exchangers. The most abundant mineral in geothermal fluid is silica and thus its precipitation can cause the highest scaling rate. While this dissertation is devoted to the study of silica scaling the results obtained may be applicable to other minerals with similar deposition mechanism. Oversaturated silica is known to precipitate from aqueous solution either by the direct chemisorption of single silicic acid molecules (monomers) or by forming colloidal particles suspended in the solution. These particles can subsequently be transported to, and attach onto, a wall. This process of colloidal silica deposition was previously recognised to cause much faster scaling than the direct deposition of silica monomers under typical geothermal plant conditions. While the chemical kinetics of silica polymerization and colloid formation are relatively well understood, transport of these colloids and their stability, which control their aggregation and attachment rates, on the other hand are not. Previous studies of the silica scaling process have identified prominent effects of geothermal brine hydrodynamics on the scaling rate. It was found to increase with the flow rate and particle size, thus suggesting the dominance of the advective (inertial) deposition of colloidal silica. However, this conclusion contradicted the present theory of particle transport in turbulent flows which argues the dominance of the diffusive transport for the relevant range of particle sizes (<1 μm). The development and continuing improvement of the anti-scaling measures required deeper understanding of the complex combination of the phenomena involved in the process of silica scaling. This was pursued in the present study using theoretical and experimental methods. First, the rate of colloidal silica transport from a turbulent flow onto the internal surface of a circular pipe, a cylinder and a flat plate were calculated using available analytical and numerical methods. The obtained theoretical transport rate was found to be about four orders of magnitude higher than the corresponding experimental scaling rate. The latter was determined in the previous studies to be 4.2·10-8 kg/s/m2 for silica colloids of 125 nm in diameter which corresponded to the dimensionless deposition velocity (the dimensionless deposition velocity is the scaling rate normalised by the particle mass concentration and friction velocity) of 1.2·10-6 for the dimensionless particle relaxation time of 2·10-4. Next, based on the standard DLVO theory of particle interactions and in the framework of the Smoluchowski approach the probability of colloidal silica particle attachment to a wall was found to be 10-6. Therefore, the theoretical scaling rate, calculated as a product of this probability and the above-mentioned transport rate was two orders of magnitude lower than the experimental scaling rate. This suggested that the implemented theoretical approach either underestimated particle transport rate or overestimated particle stability. Both possibilities are explored in this dissertation. In addition, the silica scaling rate was measured for a range of conditions: particle size from 20 to 60 nm, particle concentration 1600-10000 ppm, friction velocity from 0.09 to 0.18 m/s (Re = 9-50·103) and ionic strength from 30 to 80 mM, pH 8.1-9.5 and temperature from 25 to 44 °C. For this, laboratory experiments were designed and progressively modified in order to improve the repeatability of the results and to study the scaling process. In these experiments colloidal silica deposition onto the walls of mild steel pipe sections was studied with a recirculating flow rig with variable (but controllable) particle size, concentration, flow rate, pH and ionic strength of the solution. In addition, a parallel plate flow test section was designed and built which will provide better capabilities for the control over the hydrodynamic and test surface conditions in future experiments. The control over the chemical conditions was achieved by the use of the synthetic colloidal solutions. Two methods of their production – hydrolysis of either sodium metasilicate or active silicic acid – were employed. The influence of the synthesis conditions, ion content and pH on the long term behaviour of these colloidal solutions was investigated. The particle size data, obtained using dynamic light scattering (DLS) and verified by electron microscopy, was analysed and compared against the predictions of the current models of nanoparticle growth and stability. The kinetic aggregation was identified to be the dominant particle growth mechanism. Experimental data collected during the long-term observations of the particle growth allowed relationships between the aggregative stability and such parameters as the particle size, ion concentration and pH of the solution to be elucidated. In particular, the aggregative stability of 10-20 nm particles was found to be 108-1010 which is 7-9 orders of magnitude higher than the corresponding DLVO stability. It was also found to decrease with the increase of the particle size. This agreed with the theory of the colloid stabilization by steric interactions. Moreover, the model of the “gel” layer was used to explain the observed “anomalies” of the colloidal silica behaviour. The deposition experiments conducted with these synthetic colloidal solutions showed that the scaling rate increased with the particle size, flow rate and ionic strength (IS) of the solution. Thus, it was measured to be 9.7·10-9 kg/s/m2 for the 45 nm particles in a solution with IS = 0.05 M, which corresponded to the dimensionless deposition velocity of 6.6·10-8 for a dimensionless particle relaxation time of 2.2·10-6. The scaling rate was calculated for these conditions by multiplying the corresponding transport rate and the actual attachment probability determined as an inverse of the experimental stability. It was found to agree with the experimental value within an order of magnitude. In addition, the observed increase of the scaling rate with the increase of particle size was explained by the compensation of the decreased rate of the particle transport by faster decrease of actual particle stability (increase in attachment probability). Therefore the contradiction between the theory and the experiment was resolved for the particles of 20 to 60 nm in diameter. Moreover, the observations of the dimensions and distribution of the scale elements formed in some of the present experiments strongly suggested the significance of the advective (inertial) mechanism of particle deposition. This and comparative analysis of other experimental and theoretical data suggested that the present theory may underestimate the convective transport of the particles onto a rough wall. Therefore, the hypothesis of the parallel-to-wall advective deposition of the nanoparticles onto the roughness/scale elements (not accounted in the current theory) was proposed. The corresponding mass transfer problem was solved analytically using experimentally found dimensions of the scale elements. The additional transport was found to decrease the above-stated discrepancy between the theoretical and experimental scaling rate for large (125 nm) particles by one order of magnitude. The remaining difference of one order of magnitude was speculated to be due to the underestimation of these particles attachment probability derived with the standard DLVO theory. The actual aggregative stability of the silica colloids larger than 60 nm in diameter and for a wider range of IS values is of interest for future experimental studies. An improved understanding of the interrelation between the chemical and hydrodynamic phenomena in the process of silica scaling and its dominant mechanisms was achieved in this dissertation. This allowed optimization of the present anti-scaling practices aimed to minimize the negative effects of mineral scaling on the operation of geothermal power stations. Besides the practical recommendations, which may ultimately help to increase the efficiency of geothermal power stations, the results of the present study may be of value in the fields of mass transfer and colloid science.

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  • Development and optimization of an in vitro process for the production of Oryctes nudivirus in insect cell cultures

    Pushparajan, Charlotte (2015)

    Doctoral thesis
    University of Canterbury Library

    The coconut rhinoceros beetle, an economically important pest of coconut and oil palms, is effectively managed by application of its natural pathogen, the Oryctes nudivirus (OrNV), which act as a bioinsecticide. While this approach offers an environment-friendly alternative to chemical pesticides, the current method of production in infected larvae suffers from inconsistencies in virus productivity and purity. While the anchorage-dependent DSIR-HA-1179 insect cell line has been identified as a susceptible and permissive host for OrNV and therefore would be suitable for the in vitro mass production of the virus, no attempts have been made toward the mass production of the virus, because of the technological challenges that working with DSIR-HA-1179 cells represent. Thus, the main objective of this research was to develop processes for the in vitro production of OrNV in the DSIR-HA-1179 cell line. Knowledge of the growth kinetics and metabolic properties of the host cell line in a chosen culture medium, as well as the selection of an appropriate infection strategy, form the basis for the rational development of bioreactor-based virus production processes. However, characterization of these properties in the DSIR-HA-1179 cell line has been virtually precluded, due to its strongly adherent growth characteristics and the lack of a reliable method to accurately dissociate and count cells grown in monolayers. Using TrypLE™ Express enzyme, a technique allowing the precise counting of cells was developed. The cell line was adapted to grow in four serum-supplemented culture media: TC-100, IPL-41, Sf-900 II and Sf-900 III, which were then individually screened for cell growth and virus production in 25 cm2 attached T-flask cultures. TC-100 supplemented with 10% fetal bovine serum was chosen as a suitable culture medium, based on its capacity for achieving a high cell yield and OrNV production. The cell line metabolism was characterized with respect to nutrient consumption and metabolites production in this culture medium. Glucose, along with glutamine were found to be the nutrients that were consumed faster and to a greater extent, while other amino acids were not consumed to a significant degree. The production of metabolites was characterized by non-production of lactate and ammonia, and production of alanine, as a non-toxic alternative to ammonia. The influence of cell density (CD) at time of infection (TOI) and multiplicity of infection (MOI) on OrNV production was evaluated in T-flask cultures that were infected at different CDs at the TOI and a range of MOIs. The CD at TOI was found to significantly influence OrNV yields, while MOI influenced the dynamics of infection. The cell density effect was found to exist for the DSIR-HA-1179/OrNV system with the progressive decline in cell-specific yield beginning at low cell densities. It was found that in order to maximize OrNV volumetric yield, a combination of MOI and CD at TOI should be selected that allows to keep the maximum cell density reached by the infected culture within a range between 5.0 and 7.0 x 105 viable cells/ml. The roller bottle system was evaluated for its potential to scale-up DSIR-HA-1179 cell growth and OrNV production, and culture parameters were optimized for the improvement of cell and virus yields. An inoculum density of 3.3 x 105 cells/ml and culture volume of 60 ml resulted in the highest cell yield of 1.5 x 106 cells/ml, in 490 cm2 roller bottles. It was found that an optimal infection strategy for roller bottle cultures, which represented the most efficient use of viral inoculum, involved infecting cells at a density of 5.0 x 105 cells/ml and at a MOI of 1. The resulting OrNV volumetric yield of 2.5 x108 TCID50/ml, improved significantly the viral yields obtained in attached T-flask cultures infected under similar conditions (6.8 x 107 TCID50/ml). The microcarrier system was also evaluated for culturing DSIR-HA-1179 cells and producing OrNV in spinner flask bioreactors. Three types of microcarriers (Cytodex-1, Cytodex-3 and Cultispher-G microcarriers) were screened for their ability to support DSIR-HA-1179 growth. Cells attached to Cytodex-1 and 3, but failed to attach to Cultispher-G microcarriers. The final cell density reached in microcarrier culture was dependent on bead type and concentration, and the cell to bead ratio. At an optimal bead concentration of 1 mg/ml and cell to bead ratio of 30, cells grew to a maximum density of 1.7 x 106 cells/ml on Cytodex-1, but only to 1.3 x 106 cells/ml on Cytodex-3 microcarriers. Since it supported higher cell yields, Cytodex-1 was chosen to study the kinetics of OrNV production in this system. Microcarrier cultures infected at a cell density of 5.0 x 105 cells/ml and a MOI of 1, produced OrNV at 1.4 x 108 TCID50/ml, which was higher than the yield obtained in T-flask cultures infected under similar conditions. A framework of knowledge on the physiology, metabolism and growth kinetics of the DSIR-HA-1179 insect cell line has been developed in this thesis. In addition, the feasibility of using roller bottles and microcarrier systems for the in vitro production of the virus has been ascertained. It is envisaged that these findings will contribute to the future development of a large-scale industrial process for the production of the OrNV biopesticide.

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  • Irradiation as an alternative phytosanitary treatment for Arhopalus ferus and Hylurgus ligniperda

    van Haandel, Andre (2014)

    Bachelors thesis
    University of Canterbury Library

    Wood products all require treatment to mitigate phytosanitary risk prior to exportation. The most common phytosanitary treatment applied to Pinus radiata logs is Methyl Bromide (MeBr). The Environmental Protection Agency (EPA) in 2010 stated that MeBr must not be release into the atmosphere past 2020. This poses a problem for New Zealand log exports. Radiation has been identified as a possible alternative phytosanitary treatment for export wood products. This study aimed to quantify the effective dose of radiation necessary to sterilise two forest pest species; Arhopalus ferus and Hylurgus ligniperda. These species are representative of two different types of forestry pests; bark beetles (H. ligniperda) and wood borers (A. ferus). All applicable life stages for both species were tested. Arhopalus ferus adults were the most susceptible life stage identified with an LD99 of 30.2Gy ± 13.5 Gy (95% confidence interval). Arhopalus ferus eggs were less susceptible with a LD99 of 750Gy ± 776Gy observed; however there is low confidence in this result due to a methodological issue in one treatment replicate. Hylurgus ligniperda eggs were observed to be less susceptible than A. ferus eggs with a LD99 of 289Gy ± 92Gy. Results for the other life stages were inconclusive due to poor control survival, however the information gained was used to develop improved methods for further experimentation, which is on-going and showing positive results so far. The results of this experiment have indicated that radiation can be an effective method of sterilising forestry pests. To date radiation has not been used as phytosanitary risk mitigation for wood exports; however it is widely used for risk mitigation in agricultural products. Currently there remains a large amount of unknown information regarding, the effectiveness for irradiation of logs, the effective dose require for sterilisation of the most tolerant forestry pest and public acceptability of irradiation as a phytosanitary treatment. These knowledge gaps and an economic assessment must be completed before irradiation can be used as a phytosanitary risk mitigation technique for forestry products.

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  • Gold-based Nanomaterials: Spectroscopy, Microscopy and Applications in Catalysis and Sensing

    Adnan, Rohul (2015)

    Doctoral thesis
    University of Canterbury Library

    The birth of nanotechnology era has revolutionized materials science, catalysis and field of optoelectronics. Novel and unique phenomena emerge when material dimensions are reduced to ultra-small size regime and enter nanometre (2-100 nm) realm. Such novel materials are expected to replace bulk materials, offering lower cost of manufacturing and enabling progress in many areas such as solar cell, drug delivery, quantum communication and computing, catalysis and sensing applications. With the progress in nanomaterial synthesis and fabrication, the need for the state-of-art characterization techniques became obvious; such techniques help to establish a complete understanding of the nature and interactions of nanosized materials. In this thesis, the first part focuses on the synthesis of gold and ruthenium clusters, namely Au8, Au9, Au101, Ru3, Ru4 and AuRu3, using the well-established synthetic protocols in the literature. Apart from the standard lab-based characterization techniques such as nuclear magnetic resonance (NMR), UV-visible spectroscopy (UV-vis) and Fourier Transform Infra-red (FTIR), a less explored but useful technique far infra-red (far IR) spectroscopy, available at the Australian Synchrotron (AS), was employed to investigate the vibrational modes in these clusters. Peaks in the experimental far IR spectra were assigned unambiguously to specific vibrations by comparing with the ones generated via DFT calculations with the help of collaborators, group of Professor Gregory Metha, University of Adelaide. For the Au9 cluster, three significant gold core vibrations are observed at 157, 177 and 197 cm-1 in the experimental spectrum. In the case of the Ru3 cluster, only a single ruthenium core vibration is identified within the spectrum, at 150 cm-1 with the calculated force constant, k = 0.33 mdyne/Å. The Ru4 cluster exhibits two metal core vibrations at 153 and 170 cm-1 with force constants of 0.35 and 0.53 mdyne/Å, respectively. Substitution with a gold atom yielding a mixed metal AuRu3 cluster shifts the core transitions toward higher wavenumbers at 177 and 299 cm-1 with an increase in force constants to 0.37 and 1.65 mdyne/Å, respectively. This is attributed to the change in chemical composition and geometry of the metal cluster core. A combination of the DFT calculations and high quality synchrotron-based experimental measurements allowed the full assignment of the key transitions in these clusters. Next, these clusters were fabricated into heterogeneous catalysts by depositing on different metal oxide nanopowders. Synchrotron X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) studies were performed at the Australian Synchrotron and the Photon Factory synchrotron in Japan to investigate the electronic structure of Au8, Au9 and Au101 on TiO2 catalysts. The XPS analysis reveals that “as-deposited” Au8 and Au9 retain some un-aggregated clusters while Au101 show bulk-like gold. These findings are in line with TEM observations, where the aggregates (large particles, > 2 nm) of Au8, Au9 and Au101 are hardly seen under HRTEM. UV-visible diffuse reflectance spectroscopy (UV-vis DRS) studies show the absence of localised surface plasmon resonance (LSPR) peaks in these “as-deposited” clusters, suggesting they are below 2 nm in size. Importantly, the XAS spectrum of “as-deposited” Au9 clusters estimates that 60% of pure, un-aggregated Au9 clusters and 40% of bulk gold in the sample. Upon calcination under O2 and combined O2 and H2 (O2-H2), Au8, Au9 and Au101 clusters form larger nanoparticles (> 2 nm) with the appearance of LSPE peak in UV-vis DR spectra. In addition, majority of the phosphine ligands (that stabilise the gold core) dislodge and form phosphine oxide-like species by interacting with oxygen on the TiO2 surface. The third part focused on testing the catalytic performance of the supported Au8, Au9, Au101, Ru3, Ru4 and AuRu3 clusters on different TiO2, SiO2, ZnO and ZrO2 in benzyl alcohol oxidation. Au101-based catalysts display the highest catalytic activity with a turn-over frequency (TOF) up to 0.69 s-1. The high catalytic activity is attributed to the formation of large Au nanoparticles (> 2 nm) that coincides with the partial removal of capping ligands. Au8 and Au9 clusters which contain NO3- counter anions are found to be inactive in benzyl alcohol oxidation. Further work shows that the presence of NO3- species diminishes the catalytic activity. Monometallic ruthenium clusters, Ru3 and Ru4, are found to be inactive yet the bimetallic AuRu3 clusters are active in benzyl alcohol oxidation, suggesting the synergistic effect between ruthenium and gold metal. Investigation of catalytic testing parameters reveals that tuning selectivity of the product is possible through manipulating the reaction temperature. Finally, a joint experiment with Prof. Wojtek Wlodarski’s group at RMIT, Melbourne was undertaken to test the sensing ability of Au9 clusters for hydrogen detection. Au9 clusters were deposited onto radio-frequency (RF) sputtered WO3 films at two different concentrations; 0.01(S1) and 0.1(S2) mg/mL. It was found that the optimal temperatures for sensor S1 and S2 were 300 °C and 350 °C, respectively. The sensor with lower Au9 concentration (S1) displays a faster response and recovery time, and a higher sensitivity toward H2. HRTEM studies reveal that the sensor S1 contain a significant population of sub-5 nm Au nanoparticles which might be responsible for a faster rate of H2 adsorption and dissociation. The key finding in this study suggest that the addition of catalytic layer such as ultra-small Au9 clusters results in improved sensitivity and dynamic performance (response and recovery time) of H2 sensors. In summary, this thesis demonstrated that cluster-based nanomaterials have wide range of applications spanning from catalysis to sensing. Further improvements in material synthesis and use of multiple complimentary characterization techniques allowed better understanding of the nature of the key active species (metal nanoparticles) assisting design of catalysts and sensors with enhanced performance.

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  • Managing Non-Traditional Security Concerns in the Context of Competing Maritime Claims: A Path to Peace or a Road to Nowhere

    Scott, K. N. (2014)


    University of Canterbury Library

    The South China Sea (SCS), which extends over 3.5 million kilometres with an average depth of 2000 metres1 has become synonymous with intractable territorial and maritime delimitation disputes with the disagreement over the Spratly Archipelago (involving six nations - China, Taiwan, Vietnam, Malaysia, Brunei, Philippines) and the Paracel Archipelago (3 nations – Vietnam, China and Taiwan) being the most high profile of the disputes. What I would like to do in this paper, as part of this project, is to explore the extent to which a focus on non-traditional security concerns actually represents a viable pathway either to the resolution of the territorial and maritime delimitation disputes between the competing claimants or to the development of a long term interim solution whereby a framework is developed allowing states to manage the region without resolving those disputes.

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  • Small business tax compliance burden : what can be done to level the playing field.

    Ma, David (2015)

    Masters thesis
    University of Canterbury Library

    One of the major issues associated with taxation are the costs incurred by taxpayers when they comply with their tax obligations, this is particularly important for smaller business taxpayers. Compliance costs are found to be regressive, falling with disproportionate severity on smaller businesses. This trend can be found across the globe and more importantly, in New Zealand. Prior research has shown that the severity of the regressiveness has increased over time. The current, “one-size-fits-all”, approach used in the New Zealand tax system, and others alike, have created undue complexity for small businesses. This study reviews small business tax regimes and concessions currently implemented (or proposed) in different countries to relieve the compliance burden for smaller businesses. Australia, South Africa, the United Kingdom and the United States have either implemented a separate tax regime, or offers tax concessions to smaller business taxpayers. New Zealand on the other hand, presents minor ad hoc tax concessions for small business taxpayers, but since 2009, there have been proposals to change this system. This study evaluates and compares all the implemented (or proposed) regimes and concessions of the selected countries. Following from the case studies, interviews are conducted with tax professionals that have worked closely with smaller businesses, in order to shed light on the possibility of implementing a similar regime in New Zealand. The findings show that a small business tax regime has many avenues to consider, however, there is general consensus that suggests small business taxation should be kept as simple as possible. This thesis puts forward a baseline for further discussion and development of a small business regime to reduce compliance costs for smaller businesses.

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  • Investigation and Prediction of the Sound Transmission Loss of Plywood Constructions

    Wareing, Robin Richard (2015)

    Doctoral thesis
    University of Canterbury Library

    The sound transmission loss of a range of plywood panels was measured to investigate the influence of the orthotropic stiffness of the plywood panels. The plywood panels were tested as single and also double leaf partitions, with a range of stud configurations. A new method was developed for predicting the sound transmission loss of single leaf partitions with both orthotropic and frequency dependent stiffness values. The sound transmission loss was evaluated for two significantly different sample sizes. The observed influence of the sample size on the measured sound transmission loss was profound. The construction of the partition was shown to significantly affect the influence of the sample size on the sound transmission loss. A qualitative analysis based on existing published research of the contributing factors is presented, and methods for adjusting the results for the small sample size for comparison with the large results were developed. The influence of a range of acoustic treatments of lightweight plywood partitions was investigated. The treatments involved internal viscoelastic materials and decoupled mass loaded barriers in various arrangements. The attachment between the treatment and the plywood panel was found to influence the sound transmission loss significantly. A prediction method based on published models was modified to allow the influence of the treatments to be included. Reasonable agreement was achieved between the predicted and measured results for a wide range of samples. A prediction method was developed that accounts for the influence of orthotropic, frequency dependent material parameters. This method utilised an adaptive, numerical integration method to solve an analytical formulation for the sound transmission loss. The influence of the finite sample size was accounted for using an expression for the finite panel radiation impedance. The finite panel radiation impedance was predicted analytically and an approximation was also presented. The presence of a significant source room niche was accounted for by applying an appropriate limit to the integration range of the angle of incidence. The prediction methods developed are compared with the measured transmission loss results from both the small and large test facilities. Good agreement was seen for some of the predicted results. Generally the agreement within the coincidence region was worse than for the rest of the transmission loss curve. The inclusion of orthotropic and frequency dependent stiffness values significantly improved the agreement within the coincidence region.

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  • A Capabilities Solution to Enhancement Inequality

    Swindells, Fox (2014)

    Masters thesis
    University of Canterbury Library

    Human enhancements will dramatically alter individuals' capabilities and lead to serious harm if unregulated. However, it is unclear how states should act to mitigate this harm. I argue that the capabilities approach provides a useful metric to determine what action states should take regarding each enhancement technology. According to the capabilities approach, states are responsible for ensuring their citizens are able to function in certain ways that are essential to human life. I consider the impact of a range of enhancements on individuals' capabilities in order to determine what actions states should take regarding each technology. I find that in order to be just and prevent harmful inequality, states will need to ensure many enhancements are available to their citizens. I also explore a range of other regulations aimed at harm prevention. Considering the impact of enhancement technologies on human capabilities, and the appropriate regulatory options for states, under the guide of the capabilities approach allows me to demonstrate that the capabilities approach can provide valuable, realistic, advice to guide public policy in response to enhancement technologies.

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  • Refinement and Normalisation of the University of Canterbury Auditory-Visual Matrix Sentence Test

    McClelland, Amber (2015)

    Masters thesis
    University of Canterbury Library

    Developed by O'Beirne and Trounson (Trounson, 2012), the UC Auditory-Visual Matrix Sentence Test (UCAMST) is an auditory-visual speech test in NZ English where sentences are assembled from 50 words arranged into 5 columns (name, verb, quantity, adjective, object). Generation of sentence materials involved cutting and re-assembling 100 naturally spoken ‟original” sentences to create a large repertoire of 100,000 unique ‟synthesised” sentences. The process of synthesising sentences from video fragments resulted in occasional artifactual image jerks (‟judders”)‒quantified by an unusually large change in the ‟pixel difference value” of consecutive frames‒at the edited transitions between video fragments. To preserve the naturalness of materials, Study 1 aimed to select transitions with the least ‟noticeable” judders. Normal-hearing participants (n = 18) assigned a 10-point noticeability rating score to 100 sentences comprising unedited ‟no judder” sentences (n = 28), and ‟synthesised” sentences (n = 72) that varied in the severity (i.e. pixel difference value), number, and position of judders. The judders were found to be significantly noticeable compared to no judder controls, and based on mean rating score, 2,494 sentences with ‟minimal noticeable judder” were included in the auditory-visual UCAMST. Follow-on work should establish equivalent lists using these sentences. The average pixel difference value was found to be a significant predictor of rating score, therefore may be used as a guide in future development of auditory-visual speech tests assembled from video fragments. The aim of Study 2 was to normalise the auditory-alone UCAMST to make each audio fragment equally intelligible in noise. In Part I, individuals with normal hearing (n = 17) assessed 400 sentences containing each file fragment presented at four different SNRs (-18.5, -15, -11.5, and -8 dB) in both constant speech-shaped noise (n = 9) and six-talker babble (n = 8). An intelligibility function was fitted to word-specific data, and the midpoint (Lmid, intelligibility at 50%) of each function was adjusted to equal the mean pre-normalisation midpoint across fragments. In Part II, 30 lists of 20 sentences were generated with relatively homogeneous frequency of matrix word use. The predicted parameters in constant noise (Lmid = 14.0 dB SNR; slope = 13.9%/dB ± 0.0%/dB) are comparable with published equivalents. The babble noise condition was, conversely, less sensitive (Lmid = 14.9 dB SNR; slope = 10.3%/dB ± 0.1%/dB), possibly due to a smaller sample size (n = 8). Overall, this research constituted an important first step in establishing the UCAMST as a reliable measure of speech recognition; follow-on work will validate the normalisation procedure carried out in this project.

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  • “You Want To Capture Something that Will Make People Change”: Rhetorical Persuasion in The Cove, Whale Wars, and Sharkwater.

    Stewart, Jessica (2014)

    Masters thesis
    University of Canterbury Library

    Dolphins, whales, and sharks are some of the world’s most iconic animals. Yet, many people will only ever see these animals via the media. The media, then, hold significant power in creating, modifying, or reaffirming the imaginaries around various species which, in turn, influences how much concern is given to matters related to their welfare and conservation. Given the environmental and ecological concerns presently facing the ocean, protecting, conserving, and preserving the marine ecosystem is vital, and time is of the essence. Through the work of activists, three specific marine wildlife issues have received a lot of publicity across various forms of mainstream media: the killing of dolphins in Taiji, Japan for their meat; Antarctic whaling; and the practice of shark-finning. Three activist films, namely The Cove (2009), Whale Wars (2008-), and Sharkwater (2006), are centred on these issues, and filmmakers attempt to compel viewers to support the activists’ protectionist cause. In order for this goal to have a chance of coming to fruition, rhetorical arguments must be carefully crafted. Yet, the study of rhetoric in animal-focused activist films is still an understudied research area. This thesis contributes to this area of research by using the aforementioned films as case studies by applying Aristotle’s rhetorical proofs of ethos, pathos, and logos to analyse the rhetorical arguments. Ethos is demonstrable when the activists construct themselves as credible, moral heroes and the animals as possessors of positive traits worth protecting, and the hunters as immoral villains. The graphic imagery of animal death appeals to pathos to stir strong bodily and emotional responses such as sadness, and disgust in order to mobilize audience support for cause. Lastly, these films appeal to logos through the use of culturally authoritative discourses such as those of biology, western conventional medicine, and the legal system. This thesis essentially argues that these texts work rhetorically and discursively to persuade audiences to feel a connection with and sympathy towards the animals; to be supportive of the activists; and to prompt antipathy towards the hunters and industry spokespeople.

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  • The temperature dependence of the far-infrared-radio correlation in the Herschel-ATLAS

    Smith, D.J.B.; Jarvis, M.J.; Hardcastle, M.J.; Vaccari, M.; Bourne, N.; Dunne, L.; Ibar, E.; Maddox, N.; Prescott, M.; Vlahakis, C.; Eales, S.; Maddox, S.J.; Smith, M.W.L.; Valiante, E.; de Zotti, G. (2014)

    Journal Articles
    University of Canterbury Library

    We use 10,387 galaxies from the Herschel Astrophysical TeraHertz Large Area Survey (HATLAS) to probe the far-infrared radio correlation (FIRC) of star forming galaxies as a function of redshift, wavelength, and effective dust temperature. All of the sources in our 250 μmselected sample have spectroscopic redshifts, as well as 1.4GHz flux density estimates measured from the Faint Images of the Radio Sky at Twenty centimetres (FIRST) survey. This enables us to study not only individual sources, but also the average properties of the 250 μm selected population using median stacking techniques. We find that individual sources detected at 5 in both the H-ATLAS and FIRST data have logarithmic flux ratios (i.e. FIRC q parameters) consistent with previous studies of the FIRC. In contrast, the stacked values show larger q , suggesting excess far-IR flux density/luminosity in 250 μm selected sources above what has been seen in previous analyses. In addition, we find evidence that 250 μm sources with warm dust SEDs have a larger 1.4GHz luminosity than the cooler sources in our sample. Though we find no evidence for redshift evolution of the monochromatic FIRC, our analysis reveals significant temperature dependence. Whilst the FIRC is reasonably constant with temperature at 100 μm, we find increasing inverse correlation with temperature as we probe longer PACS and SPIRE wavelengths. These results may have important implications for the use of monochromatic dust luminosity as a star formation rate indicator in star-forming galaxies, and in the future, for using radio data to determine galaxy star formation rates.

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