4,040 results for The University of Auckland Library, Thesis

  • Evaluation of utilisation of the Prevention of Mother-to-Child Transmission of HIV Programme in Central province, Kenya

    Ngugi, Catherine Njeri (2013)

    Masters thesis
    The University of Auckland Library

    Background: The PMTCT HIV programme has been one of the most successful HIV preventive interventions towards HIV-free future generations. However, even though the programme is virtually effective in developed countries, many developing countries are reporting child HIV infections due to the MTCT. The programme has existed in Kenya for more than a decade, yet in 2011, 12,894children were HIV infected due to MTCT Objective: To evaluate the PMTCT programme, especially the HIV testing from the antenatal period to the postnatal period among expectant parents attending Nyeri Provincial General Hospital in Central Province, Kenya. Design: Retrospective analysis of the hospital registers. Methods: Three hospital registers were analysed for the period from July 2009 to September 2012. The registers were for antenatal, intrapartum and postnatal care respectively. Each register documented the utilisation of PMTCT services by the expectant parents. Descriptive and inferential statistics were produced to analyse data from the registers. Results: The PMTCT services utilisation was sub-optimal. Of the 504 expectant mothers who attended the antenatal clinic, 59.9% came once, 80.4% had their first visit in the third trimester (between weeks 28 and 40) and only 6.9% were accompanied by their partners. All the women were HIV tested in their first visit but only 12.1% were rescreened after three months, and only 3.8% had been tested prior to the current pregnancy (p=0.000). No expectant mother was tested for HIV intrapartum or postpartum. The children of the 504 mothers who were HIV tested were those whose parent/s were known to be HIV positive or who had presented to a child welfare clinic with recurring symptoms suggestive of a failing immune system. Conclusion: Public health programs need to strengthen the PMTCT and HIV prevention programmes to ensure that HIV testing preconception and in pregnancy is fully implemented and strengthened, alongside continued education of the public through community programmes and the media. To avert further horizontal and vertical transmission of HIV, there is a need to address urgently the identified missed opportunities in the PMTCT program. These programmatic challenges require health system redesign and strengthening, resource allocation, addressing research gaps and reassessing the current PMTCT policies.

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  • Analysis and Modelling of Probes in Waveguides and Mobile Radio Propagation and Systems Engineering

    Williamson, Allan (2008)

    Doctoral thesis
    The University of Auckland Library

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  • The Special Court for Sierra Leone: Justice for whom?

    Mahony, Christopher (2007)

    Masters thesis
    The University of Auckland Library

    The thesis examined the divergence of conceptions of justice between civil society actors in Sierra Leone and personnel working at the Special Court for Sierra Leone.

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  • Physiological effects of periconceptional undernutrition

    Jaquiery, Anne (2006)

    Doctoral thesis
    The University of Auckland Library

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  • Effective pedagogical strategies for language revitalization in Māori-medium Professional Development Contexts

    Tamati, Sophie (2006)

    Masters thesis
    The University of Auckland Library

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  • Investigating the Web Search Behaviors of Translation Students: An Exploratory and Multiple-Case Study

    Enriquez Raido, Vanessa (2011)

    Doctoral thesis
    The University of Auckland Library

    The translator’s role as an information user, processor, and producer in today’s multilingual and multicultural society emphasizes the need for the development of information skills that can be used both for problem solving in domain-specific translation and knowledge acquisition in a number of fields of expertise. The empirical study of dictionary use by (student) translators, for example, represents a significant area of research in Translation Studies. So does the study of additional online and offline resources. Yet, research into the use of the Web as an external aid has frequently occupied a secondary position in the investigation of translation processes. Moreover, there are hardly any studies addressing the information behavior of (student) translators within the domains of documentation, user studies, and information literacy. This essentially exploratory and multiple-case study aims at bridging this gap in the literature by exploring the Web search behaviors of a total of six participants. These include a naturally occurring sample of four postgraduate translation trainees (in their first year of studies) who enrolled in an introductory course on technical and scientific translation, and two additional subjects (a PhD student of translation with three years of casual professional translation experience and a translation teacher with over 15 years of experience in the discipline) who participated in a pilot study conducted prior to the main study. Given that the need to seek, retrieve, use, and generate translation information depends on the type of users and the translation tasks performed, the study focuses on two specific tasks dealing with the translation of two popular-science texts from Spanish into English. In particular, the study examines the online search behaviors of all participants in relation to a number of translation task attributes (text type and translation brief) as well as user attributes (translation expertise, Web search expertise, and domain knowledge). While for the first task data was obtained from all six research participants, the second task was only carried out by the four translation trainees. The participants’ Web search behaviors embedded in translation are monitored on the basis of the notion of “Web search task,” which in turn is conceptualized as involving four main information-seeking/problem-solving stages, or units of analysis: (a) The search need, or recognition of an information need as perceived within the context of translation problem solving; (b) the search goal(s), or type(s) of information required to potentially satisfy a specific information need; (c) the search process, or online actions carried out within one or more search sessions that may address single or multiple infor-vi mation needs; and (d) the search outcome(s), or type(s) of information potentially selected and/or used to (a) satisfy a search need, and (b) eventually solve a translation problem. For the in-depth study of the participants’ Web search tasks, this investigation uses case study research and combines various qualitative and quantitative sub-methods, datacollection tools, and data sources for triangulation purposes. In particular, the study employs direct observation via screen recording and survey research using two types of questionnaires (a background questionnaire and an online search report) as well as semistructured interviewing. The data sources include the completed background questionnaires, the translated texts obtained from the two translation tasks, the online search reports completed for each task, the corresponding screen recordings, and the one-to-one interviews conducted with the student participants. Qualitative analyses supported by descriptive statistics are used to process the data and provide a multifaceted overview of the participants’ Web search behaviors concerning their depth and range of research, their degree of iterative (repetitive) behavior, as well as their query construction and query modification patterns, among others. The main findings of this study suggest that participants’ level of translation expertise had a bearing on their choice of information sources, which, in turn, seemed to affect their degree of iterative online search behavior. A look at task-related factors—in particular the degree of specialization—suggests that increased task complexity (along with increased translation experience) also influenced the participants’ choice of resources. Furthermore, task-related attributes appear to have had a bigger impact on the participants’ range of search behavior than on their depth of research. In addition, it was generally observed that the lower the level of Web search expertise (and translation expertise), the more basic and unplanned the search statements and the less sophisticated the refinement of queries. Finally, both domain knowledge and taskrelated factors appeared to have had a combined effect on the participants’ amount and type of information needs. In general, it was noted that the higher the level of perceived domain knowledge, the lower the number of information needs and the less specialized the nature of these needs. Furthermore, both the type of research and the amount of time spent online seemed to have had an impact on translation quality. Overall, the more indepth the nature of research and the higher the increase in research time, the higher the level of translation quality.

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  • Superantigens as vaccine delivery vehicles for the generation of cellular immune responses

    Hughes, Jacelyn (2006)

    Doctoral thesis
    The University of Auckland Library

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  • Molecular characterisation of the EAS gene cluster for ergot alkaloid biosynthesis in epichloe endophytes of grasses

    Fleetwood, Damien (2007)

    Doctoral thesis
    The University of Auckland Library

    Clavicipitaceous fungal endophytes of the genera Epichloë and Neotyphodium form symbioses with grasses of the family Pooideae in which they can synthesise an array of bioprotective alkaloids. Some strains produce the ergot alkaloid ergovaline, which is implicated in livestock toxicoses caused by ingestion of endophyteinfected grasses. Cloning and analysis of a plant-induced non-ribosomal peptide synthetase (NRPS) gene from Neotyphodium lolii and analysis of the E. festucae E2368 genome sequence revealed a complex gene cluster for ergot alkaloid biosynthesis. The EAS cluster contained a single-module NRPS gene, lpsB, and other genes orthologous to genes in the ergopeptine gene cluster of Claviceps purpurea and the clavine cluster of Aspergillus fumigatus. Functional analysis of lpsB confirmed its role in ergovaline synthesis and bioassays with the lpsB mutant unexpectedly suggested that ergovaline was not required for black beetle (Heteronychus arator) feeding deterrence from epichloë-infected grasses. Southern analysis showed the cluster was linked with previously identified ergot alkaloid biosynthetic genes, dmaW and lpsA, at a subtelomeric location. The ergovaline genes are closely associated with transposon relics, including retrotransposons, autonomous DNA transposons and miniature inverted-repeat transposable elements (MITEs), which are very rare in other fungi. All genes in the cluster were highly expressed in planta but expression was very low or undetectable in mycelia from axenic culture, including under nitrogen-, carbonor phosphate-limited conditions. Comparative analysis of the EAS gene cluster in four different epichloë strains showed marked differences in gene expression and ergot alkaloid synthesis. Gene order is conserved in each strain although evidence for recombination between two MITEs and expansion or reduction of a simple sequence repeat (SSR) at a single intergenic region was observed. Heterologous expression of a candidate regulatory gene, laeA, from Aspergillus nidulans, which is a global regulator of secondary metabolism in aspergilli, did not affect eas gene expression. This, along with phylogeny and microsynteny analysis, suggests there is not an orthologue of this gene in epichloë. This work provides a genetic foundation for elucidating biochemical steps in the ergovaline pathway, the ecological role of individual ergot alkaloid compounds, and the regulation of their synthesis in planta.

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  • Implications of Circadian Biology for Anaesthesia

    Cheeseman, James (2007)

    Doctoral thesis
    The University of Auckland Library

    Biological clocks pervade human physiology and behaviour. They control the daily timing of sleep and dictate changes in body temperature, heart rate, the perception of pain and variable responses to drugs. Anaesthetists have taken a conservative approach to adopting the principles of chronobiology. Patients are often treated rigidly as homeostatic organisms without regard to when drugs might have greater effect or when toxicity might better be tolerated. Anaesthetists working rotating shifts around the clock battle against the effects of circadian disruption and fatigue which may lead to performance deterioration and an increase in the instance of drug error. In this thesis the implications of circadian biology for anaesthesia are examined both with respect to the patient and the anaesthetist. Anaesthetists self-report an overall sleep debt (45 min/night) which may contribute to drug error. Objective measures of sleep and performance were measured using actigraphy, a validated psychomotor vigilance task (PVT), and a novel drug recognition performance test (DRPT) developed here. The quantity and quality of sleep was significantly worse (p = 0.019) on night shifts (mean 5.51 h (SE 27 min)) vs. day shifts (mean 6.90 h (SE 26 min)). Sleep deprivation was reflected in all measures of performance. DRPT performance was significantly worse (p = 0.001) during night shifts (mean speed 8.07 (SE 0.23)) than during days (mean speed 8.48 (SE 0.23). Anaesthetists made twice as many drug errors (n=12) at the conclusion of night shifts than at any other time of the day. A clinical trial was undertaken to examine the circadian variation in the action of the neuromuscular blocker rocuronium. Patients remained paralysed for up to 15 to 20 minutes longer in the morning than in the afternoon. The maximum duration (50 mins (SE 5 mins)) fell between 08:00 and 11:00 and the minimum duration (29 mins (SE 3 mins)) between 14:00 and 17:00 (p = 0.005). A pilot study tested the effects of anaesthesia, surgery and hospitalisation on the quality and quantity of sleep patients obtained. Sleep patterns were measured for a week pre and postoperatively and up to a week in hospital. Increasing sleep disruption was associated with longer hospital stay and low light exposure. In isolation the effects of circadian biology on the system of anaesthesia are significant and when considered together they have profound implications for the conduct of anaesthesia, and for the well-being of patients and anaesthetists.

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  • Isolation of new secondary metabolites from New Zealand marine invertebrates.

    Wojnar, Joanna (2008)

    Doctoral thesis
    The University of Auckland Library

    This study describes the isolation and structure elucidation of several known and 13 new compounds from New Zealand marine organisms. Furthermore, it describes the development of a digital mask program for the analysis of HSQC spectra of crude sponge extracts. This was used as a screening tool to identify secondary metabolite producers that warranted further analysis. As reports of metabolites from New Zealand nudibranchs are poorly represented in the literature, a study of five New Zealand nudibranch species was undertaken. These coloured and seemingly undefended nudibranchs are known to concentrate or sequester toxic metabolites from their prey, facilitating rapid isolation and structure elucidation of these metabolites. This study resulted in the isolation of a variety of metabolite classes; two new compounds, 13alpha- acetoxypukalide diol (30) and lopholide diol (31) from the nudibranch Tritonia incerta, are described. Examination of the sponge Raspailia agminata resulted in the isolation of a novel family of partially acetylated glycolipids which contain up to six glucose residues. The chromatographic separation of these compounds was a challenge due to the similarity of the congeners and their lack of a chromophore. MSguided isolation eventually led to the purification of agminosides A-E (145-149). An unidentified sponge of the order Dictyoceratida was found to contain a new isomer (186) of the known sesterterpene variabilin. As variabilin-type compounds are predominantly found from sponges of the family Irciniidae, the unidentified sponge is most likely an irciniid. In addition, the sponge contained two prenylated quinones, one of which, 189, is a new isomer of a known sponge metabolite. The sponge Darwinella oxeata contained four new nitrogenous diterpenes of the aplysulphurane (rearranged spongian) skeleton, oxeatamide A (214), isooxeatamide A (215), oxeatamide A 23-methyl ester (216) and oxeatamide B (217).

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  • Telecommunications Inc.: Korea's Challenge to Qualcomm

    Kim, Sung-Young (2009)

    Doctoral thesis
    The University of Auckland Library

    Building on the success of the 1990s, in the past decade the Korean state has attempted a transition from a strategy based on catching-up to one based on innovation in the domestic telecommunications industry, which I call ‘Telecommunications Inc.’. Concomitant with this shift is a new set of challenges for the state in supporting companies that seek to reap first-mover advantages. How, if at all, has the Korean state supported the technological upgrading ambitions of domestic firms in the telecommunications industry in an era of greater economic openness? The core contention of this study is that the Korean state has coped with economic openness through adapting institutions. The existence of a ‘quasi-pilot agency’, the extension of new linkages to a wider array of private sector participants, and the emergence of ‘technology-centred forums’ represent the fine-tuning of organisational arrangements to cope with the pressures of global technology-based competition. The emergence of WTO rules appears to have helped recast rather than ruled out developmental strategy in the Korean telecommunications industry. The Korean state has coped with the rise of the global trade regime by adopting development strategies based on ‘exploiting’, which entails increasing state activism in areas not explicitly prohibited and proactively embracing rules that encourages greater state activity. The Korean state has coped by ‘modifying’ such rules to meet strategic industry objectives; either by using overt measures that take advantage of loopholes and ambiguities contained in the legal texts of the WTO and by using covert below-the-radar measures. I demonstrate my argument through an examination of the goals, underlying strategic motivations and the strategy involved in the Korean Government’s promotion of three technological standards related to telecommunications software, fourth generation mobile broadband, and mobile broadcasting.

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  • Demystifying the Mosuo: The behavioral ecology of kinship and reproduction of China's "last matriarchal" society

    Mattison, Siobhan (2010)

    Doctoral thesis
    The University of Auckland Library

    Virtually every human endeavor is accomplished with some form of assistance from kin. From subsistence activities to child rearing to the provision of emotional support, relatives are called on to aid their kin. Yet while the importance of families to individuals arguably is universal, family systems are extremely variable in terms of their composition, the services they provide, and how services are organized and allocated. This dissertation examines the factors underlying variation in kinship systems in a population of agropastoralists currently undergoing economic and cultural transition: the ethnic Mosuo of Southwest China. Through the lens of behavioral ecology, it views kinship systems as dynamic, responding flexibly and adaptively to changes in social, cultural and ecological circumstances. The first chapter introduces the basic questions that this dissertation aims to address, the context surrounding my interests in the Mosuo, and basic descriptions of the field site and methodology. The second chapter tests a recent behavioral ecological model of matrilineal inheritance, asking whether Mosuo inheritance varies predictably according to source of wealth. It explains a hypothesized link between matriliny and resource paucity, and provides the first independent evidence in support of the behavioral ecology model under test. In the third chapter, I explore the impacts of economic differences on Mosuo reproduction and kinship, showing that wealth is associated with higher levels of marital commitment, as evidenced by increased stability in reproductive partnerships, and other departures from stated matrilineal norms. The fourth chapter examines the impacts of wealth and residential ecology on paternal investment in children, arguing that in contrast to previous assertions, fathers are important among the Mosuo, and that fathers’ levels of investment in child rearing varies according to the resources they have to provide and local availability of reproductive partners. The fifth and final chapter of my dissertation summarizes the evidence presented in previous chapters and suggests specific avenues for future research. I conclude by emphasizing the power of behavioral ecology to understand the ultimate foundations of kinship.

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  • Computer-administered cognitive behavioural self-help intervention for adolescents with mild to moderate depressive symptoms: programme development and examination of feasibility, efficacy and acceptability

    Stasiak, Karolina (2008)

    Doctoral thesis
    The University of Auckland Library

    The aim of this project was to design and evaluate the feasibility, efficacy and acceptability of a developmentally appropriate computerised self-help programme for adolescents with mild to moderate depressive symptoms. The project consisted of three phases. The first phase involved the development of a conceptual framework based on learning theories and relevant instructional and media design concepts. Subsequently a prototype of a computer-administered cognitive behavioural therapy (CCBT) was designed. A matching computerised psychoeducational (CPE) programme was also developed to control for non-specific factors. The second phase involved a small randomised controlled trial to pilot the efficacy of CCBT versus CPE. Thirty-four adolescents who scored at least 30 on Child Depression Rating Scale-Revised (CDRS-R) or 76 on Reynolds Adolescent Depression Scale-2 (RADS-2) were randomly assigned to either CCBT or CPE condition. 94% of CCBT and 82% of CPE participants completed the intervention. Controlling for age and gender, repeated measures ANOVA showed a significant decrease on CDRS-R for the older (16-18 year old) adolescents compared with CPE condition (F(2,24)=13.890, p<0.005). ACS Non-productive Coping was significantly reduced by CCBT compared with CPE in younger and older adolescents (F(2,56)=5.19, p=0.009). Pediatric Quality of Life measure showed a significant improvement for all participants but showed no group differences (F(2,56)=4.56, p=0.014). The third phase of the project aimed to generate user feedback through a questionnaire (n=21) and in-depth interviews (n=14) with adolescents who had completed either of the programme. Adolescents found the programmes equally useful, easy to use and engaging. According to adolescents the programmes communicated three key messages: education about depression, validation of feelings and hope for recovery. Content specific feedback suggested that CCBT taught some adolescents cognitive restructuring and problem solving. Among the most useful CPE topics were anger management and stress reduction. Suggestions for improvement included more use of interactive/game-like technology, programme customisation and reduction of text in favour of multimedia presentation. New topics such as dealing with drugs/alcohol or violence and recovery stories from credible role models were also suggested. The results and implications of the study are discussed in the light of a growing interest in the use of computer-administered mental health interventions. Suggestions for future research and programme development are outlined

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  • Structural studies of the sugar-binding protein from the pneumococcal raffinose transport system

    Paterson, Neil (2007)

    Doctoral thesis
    The University of Auckland Library

    Streptococcus pneumoniae (the pneumococcus) is a Gram-positive bacterium responsible for a large number of deaths annually due to pneumonia, septicaemia and meningitis, mainly among young, elderly and immunocompromised populations. The primary virulence factor is the polysaccharide capsule that surrounds the cell and confers protection from phagocytosis; in addition the organism surface is decorated with a variety of proteins attached by both covalent and non-covalent means, with many of these also being involved in virulence. The pneumococcus is highly dependent on a wide range of carbohydrates for energy and growth with both phosphotransferase systems (PTS) and adenosine triphosphate binding cassette (ABC) transport systems utilised in sugar importation. Included among these is an ABC transport system, the Raf system, responsible for the importation and initial metabolism of the trisaccharide raffinose (α-D-Galp-(1→6)-α- D-Glcp-(1→2)-β- D-Fruf) that is highly sequentially homologous to the multiple sugar metabolism (Msm) system from S. mutans. The transporter itself comprises an extracellular raffinose binding protein (RafE), two membrane permease domains (RafF and RafG) and a protein responsible for adenosine triphosphate (ATP) binding and hydrolysis that has yet to be definitively identified. The 46.6 kDa substrate binding protein from the Raf system, RafE, is attached to the surface of the cell by means of a posttranslational lipoprotein modification and is responsible for the initial detection and capture of raffinose and conveying it to the transmembrane domains. RafE has been successfully overexpressed and purified to homogeneity using a novel interaction with a gel filtration matrix. Biophysical characterisation of RafE revealed the protein to be monomeric with one raffinose binding site per molecule and an affinity of 337μM for raffinose. Affinity for melibiose (α-D-Galp-(1→6)-α- D- Glcp), a substrate of the Msm system, was determined to be 6.84mM although the Raf system is incapable melibiose transport. Purified RafE was crystallised in both native and selenomethionine-labelled forms allowing solution of the phase problem by single wavelength anomalous dispersion (SAD) to a resolution of 2.90Å. Subsequent rational truncation and a change of construct to facilitate polyhistidine tag removal has produced two different crystal forms diffracting to a resolution of 1.04Å with the purification tag in place and 1.40Å iii following tag cleavage. An original solution to ice-ring diffraction was utilised for collection of this latter dataset which obviated the need for potentially problematic cryoprotectant solution. The crystal structures of RafE reveal that the protein adopts the periplasmic binding protein-like II fold, in common with a number of other substrate binding components of ABC transport systems, comprising two α/β/α sandwich domains joined by a hinge region consisting of three cross-linking peptide chains with the active site located in the cleft formed between the domains. These structures allowed identification of key active site residues and also revealed a range of conformational motion between the two domains. The active site is formed from a large aromatic patch, formed from three tryptophan residues aligned with their aromatic faces exposed to the solvent, surrounded by polar and charged residues. To assess the interaction with raffinose, polyhistidine-tag cleaved RafE was crystallised in the presence of raffinose and diffraction data collected to a resolution of 2.80Å. Structure solution using molecular replacement of the separate domains revealed a substantial conformational shift compared to the apo structures, with the two domains rotated approximately 29o towards each other, closing the active site region and trapping raffinose. RafE forms direct hydrogen bonding contacts between nine residues and the hydroxyl groups of the carbohydrate coupled with stacking of the sugar rings to the aromatic surface of the tryptophan residues. Molecular modelling of MsmE based on the raffinose bound RafE was used to try to assess the differences contributing to different substrate specificity and revealed changes in the residues forming contacts to the galactose moiety of raffinose but these did not appear to fully explain the dissimilar specificities. As an additional project, work was carried out in an attempt to obtain a crystal structure, with a view to functional elucidation of the choline-binding protein CbpI. This protein is a member of a highly important family for pneumococcal virulence with proteins of diverse function sharing a common surface attachment domain that binds to the choline moieties of teichoic and lipoteichoic acids that intersperse the cell wall. CbpI has been successfully overexpressed, purified and crystallised with diffraction data measured to a resolution of 3.50Å. The diffraction data however display very high mosaic spread and structure solution by molecular replacement has not been successful.

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  • Vernalization response in Medicago truncatula

    Jaudal, Mauren (2011)

    Doctoral thesis
    The University of Auckland Library

    Vernalization is the acquisition of the competence to flower upon exposure to prolonged winter cold. The physical conditions that promote vernalization have been analyzed here in the model legume, Medicago truncatula. The length of cold treatment correlates with the promotion of floral transition. Vernalization is optimum within the 4 C- 10 C range for two weeks and tends to saturate at longer duration. Whole plants are equally responsive to vernalization treatment as imbibed seeds. FT is a key flowering time gene that has been shown in a range of plants to encode a floral signal molecule that is produced in the leaves and moves to the apex to induce flowering. There are five copies of FT-like genes in Medicago (MtFTLa-e), but only MtFTLa, MtFTLb, and MtFTLc were shown to be upregulated by vernalization. Among the MtFTLs, MtFTLa has been shown to be the major flowering time gene whose expression is regulated both by long-day (LD) photoperiod and vernalization. The duration of cold has a quantitative effect on MtFTLa expression and induction of flowering. However, vernalization-induced upregulation of MtFTLa does not occur right after the prolonged cold treatment but takes place after growth in LD photoperiods. This finding and the observation that MtFTLa is expressed only in leaves that expanded after vernalization but not in differentiated ones present prior to the treatment, suggest that vernalization is an epigenetic process that requires dividing or undifferentiated cells. Further analysis of the MtFTLa locus using chromatin immunoprecipitation techniques revealed that the epigenetic regulation of MtFTLa expression is indeed associated with changes in chromatin modification. High transcript levels of MtFTLa following vernalization are consistent with enrichment of the H3Ac mark and concurrent loss of the H3K27me3 at part of the promoter (promoter B) of MtFTLa, modifications that are linked with chromatin structure permissive for transcription. Changes in histone marks were also observed at the more distal promoter region (promoter A) of MtFTLa. identify components that might be involved in vernalization response, sequences homologous to the PHD-finger containing VIN3 and the MADS-box genes AGL19, AGL24, and SVP were identified in Medicago. Although, MtVIN3 has relatively conserved PHD and VID domains typical of the VIN3/VEL family, unlike in Arabidopsis, its expression was not significantly induced by vernalization. Ectopic expression of MtVIN3 in Arabidopsis did not alter the flowering time. MtAGL19, MtAGL24, MtSVP1 and MtSVP2 are highly-expressed in apical buds and leaves during the vegetative stage of development but minimally detected in floral organs. These MADS-box genes are not responsive to vernalization, which is expected for MtSVPs. The flowering time of Arabidopsis was not hastened by the ectopic expression of either MtAGL19 or MtAGL24. However, 35S:MtAGL24 plants exhibited floral abnormalities that phenocopy 35S:AtAGL24 plants, such as enlarged sepals, elongated carpel, greenish/leaf-like petals, stunted siliques, and delayed maturation rate and senescence of siliques. Overexpression of both MtSVP1 and MtSVP2 genes in Arabidopsis delayed flowering with accompanying floral defects including alterations in floral organ number and symmetry, elongated carpel, larger sepals and pale green petals. The severity of the floral defects also correlated with the delay in flowering time. Apical bud genes regulated by short term cold and by vernalization treatment were identified using Affymetrix GeneChip Medicago Genome Arrays. The microarray data showed that the “cold-shock” transcriptome of Medicago resembles that of Arabidopsis, which mainly involves genes implicated in the cold-acclimation pathway and putative transcription factors (TFs). Among the genes stably upregulated by prolonged cold include three genes with predicted chromatin-related functions and one uncharacterized gene annotated as “cold-responsive”. There are significantly more genes downregulated than upregulated by prolonged cold in apical buds, among of which encode products homologous to the chromatin modifier SNF-2, a FYVE/PHD zinc finger-containing protein, and a putative novel TF with annotated transcriptional repressor activity. Analysis of the leaf microarray data also showed that among the genes stably upregulated by prolonged cold treatment following growth in LD photoperiod, MtFTLa exhibited the highest fold change in expression level, consistent with its important role in vernalization response.

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  • Dietary fatty acids modulate Th1 mediated immunity within the context of inflammatory disease

    Reynolds, Clare (2008)

    Doctoral thesis
    The University of Auckland Library

    Introduction: Polyunsaturated fatty acids (PUFA) are lipids with immunomodulatory effects. There are a wide variety of studies which have demonstrated the anti-inflammatory effects of fish derived n-3 PUFA, EPA and DHA and beef/dairy derived Conjugated linoleic acid (CLA). However, the exact mechanisms through which these PUFA exert there effects are not fully understood. Therefore the main objective of this thesis was to examine the molecular mechanisms through which PUFA exert there actions in relation to inflammatory bowel disease (IBD) and sepsis. Methods: A range of methods were used to examine the molecular effects associated with IBD and sepsis. Serum, colonic and supernatant cytokines were examined using ELISA. Protein levels and interactions were examined using Western blot and immunoprecipitation. Transcription factor binding assays were carried out to determine DNA binding affinity. mRNA levels were examined using RT-PCR. Results: Results demonstrate that in the intestinal epithelial cell line, Caco-2, the precursor fatty acid TVA does not exert the anti-inflammatory effects associated with CLA. While some anti-inflammatory effects were observed it is thought that this was due to the bioconversion of TVA to c9, t11-CLA. Results from Chapter 4 demonstrated that natural beef derived CLA has the potential to reduce systemic cytokine driven inflammation associated with LPS. In addition, DC isolated from animals fed beef-CLA demonstrated reduced expression of key molecules involved in the process of inflammation. Importantly, it was shown that CLA reduced production and mRNA expression of the LPS receptor, TLR4. Additionally results demonstrated an increase in PPARγ production, this is a transcription factor which is widely associated with anti-inflammatory effects in many disease states. Experiments carried out in Chapter 5 showed the effects of a low-CLA and high-CLA beef diet on mice challenged with DSS, an agent known to induce colitis. Both diet groups developed a mild form of colitis however clinical and biochemical analysis failed to find any differential effects between the two groups. Experiment detailed in Chapter 6 aimed to demonstrate the molecular mechanisms of the n-3 PUFA, EPA and DHA in DC. Results showed that both of these fatty acids had the ability to decrease both mRNA production and supernatant cytokine levels in DC. Key transcription factors known to influence the inflammatory process were analysed. Results demonstrated that the key pro-inflammatory transcription factor NF-κB was down regulated in both EPA and DHA however, further experiments demonstrated that only DHA had the ability to reduce NF-κB:DNA binding affinity. Analysis of PPARγ, a key transcription factor known to have anti-inflammatory effects showed increased production particularly in DHA treated cells. Furthermore immunoprecipitation experiments showed that these anit-inflammatory effects may be due to a physical interaction with NF-κB following activation by PUFA. Conclusion: Overall the studies described in this thesis demonstrate that naturally derived CLA and n-3 PUFA have potential for use as functional food. Importantly results show that CLA may be more applicable for certain diseases such as septic shock rather that IBD. This may reflect mechanisms of action which are more appropriate for different disease states.

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  • Theories and Narratives: Pacific Women in Tertiary Eucation and the Social Construction of Ethnic Identities in Aotearoa New Zealand

    Mara, Diane (2006)

    Doctoral thesis
    The University of Auckland Library

    This thesis explores the possible influence of tertiary education on ethnic identity using a social constructionist approach developed by the sociologists Stephen Cornell and Douglas Hartmann. Cornell and Hartmann describe six key sites within which ethnic identity is constructed. They view ethnic identity construction as an ongoing dynamic between the cultural identities which group members bring with them, the processes of assignment made by others within the sites, and how this interplay often promotes the assertion of newly created or revived identities. Constructions sites are situations where different cultural groups interact and where they may be subject to laws, regulations and prevailing beliefs. Although Cornell and Hartmann discuss various social institutions as construction sites they do not specifically refer to educational institutions. This study builds on their approach by examining social interactions within tertiary education from the perspectives of individual Pacific women and investigates whether this institution is a site for ethnic identity formation and change. If so, what implications does this have for Pacific students and the institutions in which they are studying? The sample consisted of twenty Pacific women graduates belonging to most of the Pacific populations in Aotearoa New Zealand. Using a semi-structured interview, information was collected about their socialization in family and church and then about their experience of tertiary education and their own responses to this. When their narratives were analysed it could be seen that the women defined themselves in both primordialist and circumstantialist terms. The narratives also provided illustrations of their assignment by “others” in the form of negative stereotyping and lower expectations held by lecturers of Pacific students. The women felt that within tertiary education institutions they were treated differently from students from other ethnic groups. The consequence was increased awareness of their cultural difference and they asserted their ethnic identities in a range of ways, including finding other Pacific students to study with, or by withdrawal behaviour in class. Such treatment, together with the effects of targeted provisions at tertiary institutions, acted to strengthen the ethnic boundaries between Pacific students and others. Implications for tertiary education institutions include the desirability of consulting Pacific students about the effects of support provided on the basis of cultural identification and the need to discover whether special provisions which make Pacific students more visible leads to their academic success or encourages them to drop out.

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  • The Use of Type 1 Cytokines to Modulate Immune Responses Raised by the Gene Gun Method of DNA Delivery

    Williman, Jonathan (2007-05)

    Doctoral thesis
    The University of Auckland Library

    Since its discovery 15 years ago there has been an explosion of research in the field of DNA immunisation. Unfortunately despite early promises that DNA immunisation had the potential to cure almost any infectious disease, autoimmune disease or even cancer, progress towards clinical trials has been slow. This has been due in part to the huge range of permutations possible in delivering the DNA. One approach is to deliver the DNA by gene gun. Gene gun delivery is a very efficient way of transfecting cells however also has a number of possible disadvantages. These drawbacks include a weak immunogenicity in larger animals as well as the tendency to bias towards the development of a strong type 2 response. In an effort to enhance antigen-specific immune responses and counter the type 2 polarisation of gene gun delivery, a series of DNA vaccines were created where the extracellular portion of the hemagglutinin (HA) gene from influenza A/PR8/34 virus was genetically fused the type 1 cytokines IFNγ, IL-12 and IL-23. Interleukin-23 has been recently discovered and even though both IL-12 and IL-23 contain the p40 subunit they seem to have dissimilar functions. The vaccine constructs were first tested in cellular assays in vitro to ensure correct production and biological activity of the attached cytokines. They were then delivered in various combinations to groups of BALB/c mice to test development of immune responses and the effect of different delivery regimes. Finally mice were immunised then challenged with live influenza virus to determine the different DNA vaccines’ protective efficacy. DNA vaccines containing the HA gene alone (pHA) or fused to IFNγ (pIFNγHA), IL-12 (pIL-12HA) or IL-23 (pIL-23HA) were successfully constructed. The fusion of the HA gene to the genes for IFNγ, IL-12 or IL-23 did not significantly disturb the structure of the antigen or prevent the biological actions of the cytokines. Mice immunised three times with pHA had high titres of serum IgG1 antibody and their splenocytes produced approximately equal amounts of IFNγ and IL-5. Co-delivery of IFNγ was unable to alter immune responses regardless of whether it was delivered at the first, last or during all immunisations. Surprisingly co-delivery of IL-12 acted to suppress both antibody and cellular immune responses, possibly through an IFNγ/nitric oxide feedback loop. On the other hand co-delivery of IL-23 tended to enhanced immune responses and, while it did not significantly alter the type 1 to type 2 balance, it was able to increase the ability of mice to clear live influenza virus from their lungs when they were challenged 26 weeks after immunisation. This protection was associated with increased levels of neutralising antibody in the serum of pIL-23HA immunised mice. This research has illuminated several of the pitfalls in the development of DNA vaccines and the use of cytokine as adjuvants. However it has also broadened our understanding of IL-23 and implies that IL-23 could be effectively used to increase the development of longterm immunity after immunisation.

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  • An instrumental case study of a professional development intervention that uses unfamiliar mathematics to prompt secondary teachers' re-thinking about learning and teaching.

    Paterson, Judith (2008)

    Doctoral thesis
    The University of Auckland Library

    This study is part of a professional development project working to enhance mathematics achievement and retention in schools in a low socio-economic region in Auckland, New Zealand. Over two years teachers of senior mathematics classes from ten schools attended workshops and meetings at which mathematicians and statisticians from the University of Auckland gave talks on aspects of their academic work. These talks form basis of the intervention that is the focus of this study. The aim of the study was to determine whether, when put in the position of encountering unfamiliar mathematics, teachers would re-view their understanding of learning, and what the results of this experience would be for their understanding of students learning needs and their teaching. In the workshops prompts and questions encouraged the teachers to discuss learning and teaching. It was hypothesised that this could lead to teachers becoming more open to considering change in their practice. A framework was developed in order to categorise the teacher talk that constituted the data. Measured against this framework the data showed that the intervention was effective in encouraging approximately 40% of the group of 31 teachers who attended one or more workshops to consider or enact change in their practice. The data was re-examined at a deeper level seeking to establish how and why the teachers responded as they did. On the basis of this a model of the processes and outcomes of teacher learning in the intervention was developed. This analysis showed that three strands of experience encouraged teachers to consider change in their practice: being re-energised for teaching through being mathematically stimulated; coming to realisations about teaching through introspection and identification with students as learners; and discussing teaching within a supportive learning community. A number of factors and contexts that impacted on teachers, responses to the intervention were identified.

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  • The role of dietary antioxidants in exercise-induced oxidative stress and athletic performance

    Braakhuis, Andrea (2011-12-14)

    Doctoral thesis
    The University of Auckland Library

    Key Question Investigated While acknowledging the general concerns that many have about the antioxidant status of the general population, I have focused on the relevance of dietary antioxidants in athletes. The two broad themes of the thesis are: the effect of usual dietary intake on antioxidant status in athletes, and the impact of dietary antioxidants on athletic performance. The overall aim of this thesis was threefold: 1) To determine the antioxidant intake of athletes 2) To investigate the impact dietary antioxidant intake has on antioxidant status 3) To assess the impact of dietary antioxidants on training and performance Structure This thesis comprises seven chapters (Table 1), beginning with this introduction and ending with an overall conclusion. The thesis comprises 7 chapters separated into in 2 thematic sections, each introduced with a literature review (Table 1) and followed with 1-2 experimental studies. Table 1: Overview of doctoral thesis chapter flow Chapter 1: Introduction and Rationalisation (Preface) Thematic section: dietary intake and antioxidant status in athletes Chapter 2: Literature Review: Dietary intake, metabolism and action of vitamin C and other dietary antioxidants in active individuals Chapter 3: Development and validation of a food frequency questionnaire to assess short term antioxidant intake in athletes Chapter 4: Effect of dietary antioxidants and exercise on antioxidant status in elite rowers Thematic section: dietary antioxidants and athletic performance Chapter 5: Literature Review: Impact of Dietary Antioxidants on Sport Performance Chapter 6: Effects of dietary antioxidants on training and performance in female runners Chapter 7: Conclusion Appendices

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