2,528 results for University of Otago, Masters

  • The effects of soaking almonds on consumer acceptance and gastrointestinal tolerance

    Taylor, Heidi (2017)

    Masters thesis
    University of Otago

    Background: Nuts have a favourable nutrient composition and are an important part of a cardio-protective diet. Nuts are also high in phytate, which can reduce the bioavailability of nutrients and can be problematic for digestion. Recently, the recommendation to soak nuts to reduce phytate levels and improve gastrointestinal tolerance, has received much attention in the popular press. Unfortunately, there is no scientific evidence to support or refute soaking as a method for phytate reduction in nuts. Soaking is time-consuming, and pre-soaked products are expensive, so these claims may act as a barrier to nut consumption, which is already low within the New Zealand population. There is also no data on the acceptability of soaked nuts. The aim of this study was to assess the effect of soaking almonds on consumer acceptance and gastrointestinal tolerance. Methods: Seventy-six healthy participants were recruited from the Dunedin area to participate in an 8-week randomised crossover trial consisting of four treatment arms: 1. sliced soaked almonds, 2. sliced unsoaked almonds, 3. whole soaked almonds and 4. whole unsoaked almonds. Participants ate 30 grams/day of each nut treatment for 12 days in balanced random order. Each day participants rated their “overall liking”, “desire to consume”, and “likelihood of future consumption” of the nuts on 100 mm visual analogue scales (VAS). They also indicated the daily occurrence of gastrointestinal symptoms, and rated severity of any symptoms on a 100 mm VAS. Results: The sliced soaked almonds were rated significantly lower on all three acceptance scales compared to all of the other treatments (all P0.520). Overall, the ratings for all four treatments remained relatively stable across the 12-day period for each scale, and all mean ratings were above the midpoint. There were no significant differences in the incidence of any of the seven gastrointestinal symptoms between the four nut treatments (all P>0.174). The only significant difference for mean severity of symptoms was for flatulence, with whole soaked nuts rated significantly more severe than whole unsoaked nuts (0.59 cm vs 0.36 cm, P=0.005). Overall, the mean incidence and mean severity of all seven symptoms was very low. Conclusions: Our results suggest there is no evidence to support the recommendation to soak nuts prior to consumption as a means of improving gastrointestinal tolerance or consumer acceptance. The relative stability of the acceptance ratings, regardless of treatment, suggests nuts are resistant to monotony. It is encouraging that the majority of participants did not experience any gastrointestinal symptoms during the study, and mean overall severity was very low, indicating nuts are well tolerated by most people. Taken together, the acceptance and gastrointestinal data suggest that the recommendation to eat nuts regularly is realistic and achievable. Future research should focus on the effect soaking has on the phytate levels and nutritional composition of nuts.

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  • The impact of modernising netball umpiring at community and development levels

    Andrew, Joyce Christine (2015)

    Masters thesis
    University of Otago

    Modernisation is a paradigm that values ideals of democratic renewal, continual improvement, alignment, and efficiency (Houlihan & Green, 2009). It has influenced how government and national sports organisations (NSO) manage sport (Grix, 2009; Sam, 2009). This thesis explores how Netball New Zealand’s (NNZ) modernisation has impacted umpiring and its stakeholders (at community and development levels). More specifically, it investigates whether modernisation’s ‘logics’ (e.g., continuous improvement) and its associated technologies (e.g., whole-of-sport planning) have affected how umpiring stakeholders think and act. This research is significant to shed light on: a) the impact of modernisation on the under-researched area of umpiring, and b) what consequences arise from the combination of modernising logics/technologies, such as whether ‘target setting’ reinforces or antagonises the goal of whole-of-sport, joined up delivery. The study employs a qualitative methodology using methods of documentary analysis, semi-structured interviews and focus groups. Interviews were with four national panel members and focus groups were with two zone umpire development groups (ZUDG) which had four individuals in each. This study found modernisation’s ideals are manifest in NNZ’s umpiring structures. Democratic renewal is evident in the establishment of ZUDG’s and centre umpire development groups (CUDG). Alignment is observable in: a) the central objectives and programmes driving ZUDGs and CUDGs, and b) the adoption of similar strategies from player development into umpire development (i.e. targeting youth). Lastly, NNZ’s concern for efficiency and continual improvement has resulted in: a) specialist development personnel/groups, b) more comprehensive development programmes, and c) more squads, levels of accreditation, and fitness testing. These structures were found to: a) create greater expectations for umpiring and umpire coach/assessors, b) emphasise pathways, ambitions and status to recruit and develop umpires, and c) encourage a demographic shift in the umpire population. One major area of discussion was that modernising has increased stakeholder workloads, preventing them from fulfilling other roles such as running umpire development initiatives. High workloads also insulated some stakeholders, hindering communication and potentially preventing consistent standards, quality development programmes, and knowledge transfer between players, coaches and umpires. The high workloads may also have antagonised the sustainability of umpire development. The other main area of discussion was that modernising with ‘best practices’ of accreditation, targets, pathways and targeting youth yield many similar challenges generated by emerging professions. This study found ‘best practices’: a) privileged some over others, b) changed the umpire population’s ethos, demographics, and socio-cultural dynamics, c) created a focus on quantitative targets, and d) put unrealistic expectations on support personnel. Furthermore, this study found some modern ideals were not compatible. Continual improvement antagonised efficiency and alignment because it created large workloads. In addition, ‘best practices’ striving for efficiency, alignment, continuous improvement, democratic renewal and accountability seemed to inhibit efficiency. Overall, this study advances the importance of critically considering the consequences of modern logics and practices on the capabilities of sport organisations.

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  • The Effect of Cognitive and Perceptual Load on Attention in PowerPoint Presentations

    Furney, Piers (2016)

    Masters thesis
    University of Otago

    Lecturers have fervently converted to the PowerPoint presentation format for educating students, yet in the rush towards ease of use and popularity, thoughtful construction of lesson materials has suffered. By bouncing between under-formed bullet-points and walls of text, educators have lost students’ attention. The present studies investigated the effect manipulation of cognitive and perceptual loading of PowerPoint slides would have on attention, measured indirectly through memory recall performance. Participants experienced a presentation made up of one of two levels each of cognitive load, perceptual load, and topic. Following the presentation participants were given a memory recall test based on the information they had just viewed. Participant’s daily distractibility, lecture attendance, cognitive effort expended, and learning preferences were measured to assess what impact these additional factors would have on academic performance. The findings illustrate that a low cognitive and a high perceptual loading of educational slideware will increase student preference and test score for questions that require complex transfer of information to novel scenarios. Age, and lecture attendance were found to have a negative impact on test score: the older and more cognitively depleted participants underperformed compared against younger participants that had attended minimal lectures the day of testing. By streamlining content and integrating smart, graphical explanations to course material, it is hoped that educators can increase their PowerPoint efficacy and thus provide interesting and improved learning environments.

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  • A Comparison of Maternity Care Models and Their Relationship to Adverse Fetal and Neonatal Outcomes: A Retrospective Cohort Study Based in New Zealand.

    Moon, Elwyn Jane (2015)

    Masters thesis
    University of Otago

    Background New Zealand has an internationally unique midwife-led maternity system where four out of five pregnant women have a midwife as their lead care provider. The system was established in 1990 with the passing of legislation that allowed midwives to care for a pregnant mother without medical involvement. Before this the main care provider was typically a doctor and autonomous midwifery was illegal. The midwife-led maternity system that was enabled through this legislation has been the subject of frequent debate with supporters saying it is a model to be copied internationally and opponents questioning its safety. The debate has been ongoing since the inception of autonomous midwifery in 1990, and it has often been fuelled by media reporting on individual cases of adverse events where the blame has been put on midwifery or maternity system failures. Despite the continuous debate there has been little in the way of systematic evaluation that specifically investigates safety related outcomes in relation to New Zealand’s maternity system framework. Thesis aims • To provide a historical overview of the development of New Zealand’s maternity system • To review New Zealand based and international literature that evaluates the safety of midwife-led models of care • To investigate whether there are differences in adverse fetal and neonatal outcomes dependent on the model of maternity care provided (midwife-led or medical-led), within New Zealand. Methods The study was a retrospective cohort design using nationally held data. All pregnancies where the delivery occurred between the 1st of January 2008 and the 31st December 2011, and where the pregnancy met the following inclusion criteria were included: lead maternity carer recorded as midwife, obstetrician or general practitioner, a gestation of equal to or greater than 37 weeks, a singleton pregnancy, and where no major fetal or neonatal congenital, chromosomal, or metabolic abnormalities were identified. Patients were categorised into the exposure groups midwife-led care or medical-led care based on who their lead maternity carer was at first registration. Outcomes included perinatal related mortality, stillbirth, neonatal mortality, a low Apgar score at five minutes post-delivery, intrauterine hypoxia, birth related asphyxia, neonatal encephalopathy, neonatal hospital admission within the first week of life, and low birthweight. Potentially confounding patient characteristics that included age, ethnicity, socioeconomic position (NZDep), body mass index, smoking status, parity, timing of registration with carer, and the presence of pre-existing hypertension and/or diabetes were also measured. Results There were 371 case of perinatal related mortalities in our study giving a rate of 1.93 per 1000 total births. After adjusting for age, ethnicity, socioeconomic position, body mass index, smoking status, parity, trimester of registration with carer, and presence of pre-existing diabetes and/or hypertension the odds of this outcome were similar when comparing medical-led care with midwife-led care (midwife-led care as the reference group) OR=0.88 (95% CI 0.59-1.32). Examining stillbirth and neonatal mortality individually showed no difference in odds of stillbirth, adjusted OR=0.97 (95% CI 0.62-1.51) and lower odds of neonatal mortality for the medical-led births which were not statistically significant, adjusted OR=0.59 (95% CI 0.21-1.62). The medical-led group had significantly lower odds of low Apgar, intrauterine hypoxia, birth related asphyxia, and neonatal encephalopathy, respective adjusted OR=0.54 (95% CI 0.43-0.68), OR=0.74 (95% CI 0.56-0.99), OR=0.45 (95% CI 0.31-0.63), and OR=0.55 (95% CI 0.32-0.95) compared with the midwife-led group. The medical-led group had elevated odds of neonatal admission compared with the midwife-led group, adjusted OR=1.32 (95% CI 1.24-1.40), which was confined to level 1 (lowest level) neonatal units, adjusted OR=2.91 (95% CI 2.65-3.19); the medical-led group having lower odds of level 3 (highest level) admissions, adjusted OR=0.41 (95% CI 0.35-0.49). There was no difference in adjusted odds of low birthweight between groups, adjusted OR=1.04 (95% CI 0.91-1.20), which was included as a negative control. The two groups had statistically significant different demographic characteristics with the medical-led group consisting of older, less deprived, more often European mothers. Māori, Indian, and Pacific Island ethnicities, deprivation, high BMI, smoking, nulliparity, grand multiparity, late booking of care provider, and mothers having pre-existing diabetes and/or hypertension were all associated with increased odds of perinatal related mortality and neonatal morbidity. Discussion It is reassuring that there was no detected difference in odds of perinatal related mortality when comparing midwife-led and medical-led care. However the study was limited by sample size, a larger study population would be necessary to categorically state that there is no difference in odds of neonatal mortality. Other findings show a consistent increase in odds of adverse fetal and neonatal outcomes for midwife-led deliveries. The several findings demonstrating worse fetal and neonatal outcomes for midwife-led deliveries mean that more research is urgently required to identify the reasons for the differences observed. This study was not comparing midwifery care with medical care but rather the models of care, the intention was not to isolate the individual practitioners but rather compare actual constructs within the New Zealand maternity system. A major limitation of the study was the use of National Minimum Dataset data (of which covariates and some morbidity outcomes were based on). These data rely on the accuracy of clinical coding and there are questions relating to some fields completeness and accuracy. This study only focused on fetal and neonatal outcomes, not other indicators that measure a maternity systems safety, such as maternal mortality and morbidity and maternal satisfaction.

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  • The Effects of Direct Infusion of L-Baclofen or CGP7930 into the Dorsal Cochlear Nucleus on the Development of Noise-Induced Tinnitus in Rats

    Vulinovich, Ana (2014)

    Masters thesis
    University of Otago

    Tinnitus is a phantom auditory sensation that many experience at some point in their lives. Generally, the sensation is transient; however, an increasing number of people suffer from chronic tinnitus. Treatment options for tinnitus are limited, largely due to the lack of understanding of its underlying pathophysiology. Current literature indicates that hyperactivity within the central auditory system may be involved in the maintenance of noise-induced tinnitus. It is thought that this hyperactivity develops as a result of immediate plastic changes that occur within the central auditory system as a result of noise trauma, which includes the down regulation of gamma-aminobutyric acidergic (GABAergic) neurotransmission. Consequently, GABAergic drugs that promote inhibition are a current focus for the potential treatment of tinnitus, including GABAB receptor, L-baclofen, which has shown to reverse behavioural evidence of tinnitus in animals. However, there is a need to identify the underlying mechanisms of tinnitus generation to develop a therapeutic treatment. Recent evidence has suggested that the dorsal cochlear nucleus (DCN) is the primary generator of the observed hyperactivity. Lesion studies in animals have demonstrated that bilateral ablation of the DCN prior to tinnitus induction prevents the generation of tinnitus. The aim of the present study was to determine whether GABAB receptors located in the DCN are involved in the generation of tinnitus. In addition, the effects of local administration of GABAB agonist, L-baclofen, or GABAB positive allosteric modulator, CGP7930, into the DCN on tinnitus generation were assessed. Direct targeting of the DCN was achieved using a continuous local infusion of drugs via a micro-osmotic mini-pump for a seven day period. Tinnitus was induced on the second day of drug treatment using a unilateral acoustic trauma model. A conditioned lick suppression paradigm was used to assess tinnitus-like behaviour in animals. The paradigm used a foot shock as an unconditioned stimulus and speaker off periods as the conditioned stimulus. This resulted in the animals’ suppression of licking in response to the silent period. Animals with tinnitus additionally suppressed their licking in response to an acoustic stimulus with sensory features that resembled their tinnitus. The acoustic trauma resulted in a significant increase in auditory brainstem response (ABR) threshold of the ipsilateral ear (P ≤ 0.000). However, acoustic trauma did not produce a significant exposure effect in animals with bilateral cochlear nucleus cannula implantation, which indicated that the animals did not develop tinnitus. The limitations of the study that may have contributed to the lack of an exposure effect were recognised, which included unequal sample sizes and small animal numbers. Furthermore, local infusion of L-baclofen or CGP7930 for seven days did not produce a significant drug effect. However, since the animals did not develop tinnitus, the potential involvement of GABAB receptor activation in the DCN cannot be determined from these results.

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  • Circulating MicroRNAs in Bariatric Surgery

    Chan, Cheng Yee (2014)

    Masters thesis
    University of Otago

    Obese patients who undergo gastric bypass surgery experience metabolic changes resulting in appetite loss and the apparent disappearance of type II diabetes within days to weeks, even before weight loss occurs. The biological mechanisms underlying these changes are not well-understood. This study aimed to investigate the change in circulating microRNAs that correspond to these metabolic effects. MicroRNAs are a recently-discovered class of small regulatory molecules that play a key role in diverse biological processes, including lipid metabolism and insulin regulation. It was hypothesised that the microRNAs that change uniquely in association with bariatric surgery will be involved with the modulation of expression of genes in metabolic pathways that produce the physiological changes observed post-operatively. The overall study comprised two phases, a discovery and a validation phase. The discovery phase formed the basis of this thesis. Three groups were recruited, a Bariatric group, consisting of obese patients undergoing gastric bypass surgery, and an obese Control group and a lean Control group, consisting of patients undergoing non-bariatric surgery. For the discovery phase, both Control groups were combined into a single Control group. Fasting blood samples were taken from twelve patients in each of the Bariatric and combined Control groups at baseline, 5 days and 6 weeks post-operatively, for microRNA analysis. Patient demographics and markers of surgical response including anthropometric measures (weight, body mass index, waist-hip ratio), glycaemic parameters (insulin, HbA1c, fasting glucose), fasting lipid profile, hs-CRP, blood pressure and results of an appetite questionnaire were recorded at each time-point. Affymetrix GeneChip arrays were used to generate microRNA profiles that were compared between samples. The Qlucore software package was used to identify differentially-expressed microRNAs by principal component analysis and hierarchical clustering. MicroRNAs specific to the post-operative Bariatric group were determined, and linked to the unique obesity-related metabolic changes. The validation phase involves replication of the specific microRNA changes detected in the discovery phase in a larger number of Bariatric and Control patients at all time-points previously assessed (baseline, 5 days and 6 weeks), as well as at 3 months and 1 year post-operatively, using microRNA-specific Taqman assays. This is currently ongoing. Discovery phase results revealed 7 differentially-expressed microRNAs at 6 weeks in the Bariatric group, and 22 at the same time-point in the Bariatric diabetic sub-group. These were associated with significant clinical improvements in weight, glycaemic parameters and appetite scores at 6 weeks. In contrast, there were no differentially-expressed microRNAs at 5 days in the Bariatric group, or at either time-point in the Control group. MicroRNA-associated gene ontology and predicted pathways analysis identified regulatory associations with genes known to be involved in potentially biologically-plausible roles encompassing adipogenesis, pancreatic β-cell regulation, insulin signalling and secretion, and appetite control. These roles appear consistent with the metabolic effects seen following gastric bypass surgery: weight and adipose tissue loss, improved insulin sensitivity and glucose metabolism and decreased appetite. This work requires further validation; however, it indicates the therapeutic potential of altering levels of these unique microRNAs as novel pharmacological mechanisms that may mimic the effects of bariatric surgery.

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  • Techniques to Determine Quiet Day Curves for Subionospheric VLF Observations

    Cresswell-Moorcock, Alyson Kathleen Mary (Kathy) (2014)

    Masters thesis
    University of Otago

    The ionization rate of the upper atmosphere can be significantly increased by space weather events, examples being solar proton events (SPE), solar flares, and energetic electron precipitation from the radiation belts. An increase in the ionization rate leads to a lowering of the lower edge of the ionospheric D-region. To study the effect of space weather events on our atmosphere it is important 1) to be able to detect the events and also 2) to have some way of determining changes in the height of the D-region. Very low frequency (VLF) radio waves propagate in the waveguide between the surface of the Earth and the lower edge of the ionosphere (D-region). Changes in the height of the D-region lead to changes in the amplitude and phase of the VLF signal received at an antenna. To gain an accurate indication of the size of these changes we need to know what the undisturbed signal, known as a Quiet Day Curve (QDC), would have been if no space weather event had taken place. High power narrow-band communications transmitters operated by multiple nations provide the VLF radio signals used in this technique. In this study we use VLF radio wave observations from the Antarctic-Arctic Radiation- belt Dynamic Deposition VLF Atmospheric Research Konsortia (AARDDVARK) receivers located at Edmonton, Canada and Scott Base, Antarctica. The purpose of this study is to develop a technique for the automatic calculation of QDCs for long-period experimental subionospheric VLF data sets. To enable the quantitative evaluation of how well our QDC finding techniques identify the true QDC of a data set, we have created a suite of synthetic data layers with a known QDC and imposed perturbations similar to those seen in real VLF data. We present this evaluation and comparison between the techniques to allow determination of the best QDC finding technique from those developed. We evaluate two techniques for determining a long-period QDC by algorithm. These are Principal Component Analysis (PCA) and 2-dimensional Discrete Fourier Transforms (DFT). We also evaluate an averaging technique that finds a combined daily curve as a baseline comparison to our techniques. We further evaluate several adjustments to these techniques, endeavouring to improve the resulting QDC. We determine that the best QDC technique for data sets longer than two years is an adjustment to the DFT technique, while, for data sets shorter than two years, the best technique is PCA applied to a smoothed data set. We judge the success of our adjusted DFT technique from the finding that the typical difference between the QDC and the synthetic data background is 0.13~dB for day and 0.17~dB for night. These values are smaller than typical experimentally observed noise levels. We therefore conclude that this QDC finding technique is successful. The pre-smoothed PCA technique gives a typical difference between the QDC and the synthetic data background of 0.38~dB for day, 0.47~dB for night. We therefore conclude that this QDC finding technique is fairly successful, although not as conclusively as the DFT based technique is. We then apply our chosen QDC finding techniques, according to the length of the data sets, to the VLF observations. We apply the adjusted DFT technique to our Scott Base data sets, which span 4 years of observations, i.e., 2,103,840 minutes. We find that the QDC finding technique appears to qualitatively extract the QDC from these real data sets. In particular during solar flares, the extraction looks sensible. We provide examples of the difference between the received VLF signal and the QDC for an example day during which 10 solar flares occurred. We apply the pre-smoothed PCA technique to our Edmonton data sets, which span 20 months of usable data, i.e., 915,840 minutes. We find that this technique appears to be working, but have less confidence in its ability to extract perturbations lasting longer than a few hours.

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  • Effect of oestradiol on neurotrophin receptor expression in cholinergic neurons in vivo

    Milne, Michael Robert Dore (2014)

    Masters thesis
    University of Otago

    The basal forebrain is home to the largest population of the cholinergic neurons in the brain. These neurons are involved in a number of cognitive functions including attention, learning and memory. Basal forebrain cholinergic neurons (BFCNs) are particularly vulnerable in a number of neurological diseases with the most notable being Alzheimer’s disease, with evidence illustrating the link between decreasing cholinergic markers and the degree of cognitive impairment. The neurotrophin growth factor system is present on these BFCNs and has been shown to promote survival and differentiation on these neurons. Clinical and neurodegenerative studies have demonstrated the neuroprotective effects of 17β-oestradiol (E2) on neurodegeneration in BFCNs. It is believed that E2 interacts with neurotrophin signalling on cholinergic neurons to mediate these beneficial effects. In this study we aimed to observe if E2 influences the neurotrophin system by examining the effect of short-term ovariectomy (OVX) on neurotrophin receptor expression. Then, to determine if this effect is mediated by oestrogen receptor α (ERα), co-localisation between neurotrophin receptors and oestrogen receptor α was examined. Finally, neurotrophin receptor expression in neuron-specific ERα knockout mice was studied. To investigate the effect of E2 on neurotrophin receptor expression, coronal sections of the basal forebrain from OVX, OVX with E2 subcutaneous (s.c.) implant or sham operated cholinergic acetyltransferase-eGFP (ChAT-eGFP) mice were labelled using immunohistochemistry for neurotrophin receptors. Results confirmed that the loss of E2 in OVX mice resulted in a significant reduction in neurotrophin receptor expression in BFCN populations, with effects depending on neurotrophin receptor and region examined. The involvement of ERα in this relationship was then studied using double labelling immunohistochemistry staining for neurotrophin receptors and ERα in ChAT-eGFP mice. Results from this indicated that ERα co-localised with all the neurotrophin receptors investigated, however co-localisation between ERα and neurotrophin receptors was below 20% in the majority of basal forebrain regions. In the final experiment a similar protocol to the one used in experiment 1 was conducted on neuron-specific ERα knockout mice. Results indicated that OVX failed to affect neurotrophin receptor expression on BFCNs in knockout mice and in some regions basal neurotrophin expression was significantly lower than expression seen in wild-type C57BL/6 mice. Evidence presented in this study confirms that altering the levels of circulating E2 levels via OVX and E2 replacement significantly affects the expression of the neurotrophin receptors on BFCN, with effects differing depending on neurotrophin receptor and brain region examined. ERα was found to co-localise to a small extent with neurotrophin receptors on these cholinergic neurons, suggesting that there is potential for direct regulation of neurotrophin receptors through ERα, however indirect mechanisms are probably involved as well. The final experiment provided some evidence of an ERα mediated effect, however further studies are required to confirm its role and importance beside the effects mediated by other oestrogen receptors.

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  • Discovering the role of the Medicago truncatula SOC1 gene family in control of flowering time

    Fudge, Jared Blair (2014)

    Masters thesis
    University of Otago

    Flowering in the legume Medicago truncatula (Medicago) is promoted in spring by long day (LD) photoperiod and vernalisation, exposure to winter cold, by the transcription factor MtFTa1. In Arabidopsis thaliana, flowering is promoted by the same cues, by AtFT, to activate AtSOC1 at the shoot apex. However, in Medicago, the role of the three MtSOC1 genes in control of flowering time remains unknown. It was hypothesised MtFTa1 activates at least one MtSOC1 gene to induce flowering. This thesis aimed to discover the function and transcriptional regulation of MtSOC1 by inductive floral cues, to determine a role in the control of Medicago flowering time. The ability of each MtSOC1 gene to complement the late-flowering Arabidopsis soc1-2 mutant was examined in stable transgenic plants. 35S::MtSOC1a lines complemented soc1-2, 35S::MtSOC1b lines partially complemented, whilst 35S::MtSOC1c lines did not. Flowering time phenotypes positively associated with transgene mRNA levels in selected lines, confirmed by re-introducing AtSOC1, with 1 of 7 lines flowering at the same time as wild type (WT). MtSOC1 genes are differentially expressed in various aerial tissues under inductive conditions and all three are expressed in nodes (the location of the shoot apex), consistent with a role in flowering time. MtSOC1 expression is also observed in leaves, where MtFT genes are expressed under LD. A photoperiodic shift experiment tested MtSOC1 responsiveness to changes in photoperiod. Following a shift to 3 LD, all three genes were up-regulated in nodes and remained expressed upon return to short days (SD). As 3 LD is sufficient to commit vernalised WT plants to flowering, it is likely MtSOC1 activation is important for heralding the Medicago floral transition. MtFTa1-independent mechanisms also act to up-regulate MtSOC1 in the LD photoperiod pathway, possibly via MtFTb genes which respond to LD. During a developmental time course, MtSOC1b and MtSOC1c were strongly induced in WT plants under inductive conditions, prior to flowering. In late-flowering, vernalisation-insensitive fta1-1 mutants, expression was greatly attenuated and not up-regulated by vernalisation. In nodes of 15 day old WT plants, MtSOC1 genes were activated by vernalisation. In stable transgenic 35S::MtFTa1 Medicago, the levels of MtSOC1b and MtSOC1c were dramatically higher. Nodes of non-vernalised WT plants mimicked that of fta1-1 mutants, indicating MtFTa1 expression is important for MtSOC1 regulation. Transient over-expression of MtFTb1 + MtFD, but not MtFTa1+ MtFD, in fta1-1 leaves by Agrobacterium infiltration resulted in expression of MtPIM and a weak expression of MtSOC1a. This result may provide an insight into the LD photoperiod regulation of candidate flowering time genes downstream of MtFT genes. Under non-inductive SD photoperiod, exogenous GA3 promotes A. thaliana and tobacco flowering via a gibberellin-responsive cis-element in SOC1, when FT is low. In contrast with Arabidopsis and tobacco studies, exogenous did not promote Medicago flowering under SD photoperiod. A detailed transcriptional characterisation of MtSOC1 regulation by inductive floral cues suggests MtSOC1b and MtSOC1c are primary targets of MtFTa1 for promoting the floral transition in Medicago.

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  • A re-examination of wealth effects of dividend change announcements

    Chan, Michael (1999-07-26)

    Masters thesis
    University of Otago

    This study attempts to assess the explanatory power of the wealth transfer hypothesis, agency hypothesis and signalling hypothesis when stock prices change upon announcements of dividend changes. The evidence thus far on wealth effects of dividend policy changes is mixed. While there is preponderance of work that explains the stock price reaction as a signal of future firm performance, very little empirical work has been done on other potential explanations. The main findings of the paper suggest that a potential for reduction in agency costs is the primary driver of stock prices with information signalling playing a marginal role. We do not find any support for the wealth transfer hypothesis.

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  • Project expatriation: An exploratory examination

    Owen, Simon (2004-11-08)

    Masters thesis
    University of Otago

    This report describes an exploratory investigation into project expatriation, a form of overseas assignment rarely described and not yet formally examined in the literature, wherein an employee is sent into a foreign country to accomplish a specific set of tasks within a given period of time. Persons sent on such assignments are either managers or participants in usually technical projects in a location foreign to their home base; they repeatedly return to that home base, but expect another foreign assignment, often after a relatively short period of time. Their expectations, preparation, interactions, and relationships with the host country differ significantly from those of the traditional expatriate.

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  • Wealth effect of firms engaging in acquisitions programmes

    Yii, William Yong Ong (1999-02-26)

    Masters thesis
    University of Otago

    This paper examines the short-term and long-term performance of acquiring firms engaging in acquisitions programmes. In particular, the short-term performance around the announcement is studied in terms of the growth opportunities of acquiring firms (as proxied by Tobin's q ratio). The long-term performance after the announcement is studied with respect to growth opportunities, active/inactive acquirers and leverage level. Overall results show that the acquirers earn significant abnormal returns both in the short run and long run. However, long-term analyses reveal that the over-performance is not uniform across the full sample. High-q and high-levered firms earn significant abnormal returns while low-q and low-levered firms do not.

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  • Forecasting volatility in New Zealand bank bill futures

    Oldfield, John K (2003-08-25)

    Masters thesis
    University of Otago

    This paper compares volatility forecasts of four competing models based on historical data against implied volatility forecasts using New Zealand bank bill futures prices. Model forecasts are evaluated out of sample using mean absolute error and root mean square error and are tested for bias using regression techniques. GARCH was found to forecast volatility most accurately over 30-day and 60-day forecast periods; however, each of the five models gave similar errors over 90-day and 180-day forecast periods. Implied volatility forecasts gave the coefficient of determination for each period but systematically over forecasted volatility in all periods. When systematic bias was removed, the errors associated with this model fell below that of the GARCH model.

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  • "Drink my Blood": A Theological Rationale from the Jewish Blood Prohibitions

    van Noppen, Roland (2015)

    Masters thesis
    University of Otago

    Traditionally, in both eucharistic and non-eucharistic interpretations of Jesus’ call to drink his blood, “ingestion” means “belief.” Thus, “drinking blood” means believing in Jesus’ cross-work. Those Jews in John 6 who, out of respect for Mosaic law, “stumble” at such drinking have manifestly failed to perceive of new Christian realities. Such an analysis raises questions however. Accruing salvation by “drinking” Jesus’ blood, even metaphorically, may demonstrate the efficacy of such drinking, but not its legitimacy - not in light of the Mosaic blood prohibition. How then is faith in Jesus legitimately established by “drinking” blood? This study attempts to explain John’s assertion of the need to drink Jesus’ blood, and to derive a rationale for faith from these words, by demonstrating how drinking blood has become legitimate for his readers in light of the prohibition. First, a historical overview of interpretation is undertaken. This reveals that traditional analyses of John 6:51c-58, rather than resolving the “Jewish” objection to drinking blood, either avoid it, or obliterate it via “Christian” interpretation. A proposal emerges: perhaps the theological meanings attached to the Jewish objection to drinking Jesus’ blood may provide rewarding ground in which to search for answers as to why John insists that Jesus’ disciples do so. An exegesis of John 6 goes on to establish that in vv. 51c-58 John does indeed invite his reader to think theologically about ingesting blood. The superlative nature of the claims Jesus attaches to drinking blood, the divine sanction they presuppose, and the harsh literalism of his language all assume that drinking blood carries theological significance for John. We thus propose an hypothesis: in framing vv. 51c-58 of ch. 6, John has assumed a commonly-held theology relating to consuming blood which existed among first century Jews. Though unspoken, it is this body of ideas which lends sense to drinking blood for the Gospel’s implied reader, and which must now do so again for its real reader. An attempt to describe a first century blood prohibition theology follows, by analysis of the blood prohibition texts in Genesis and Leviticus, parts of the pseudepigraphical Book of Jubilees, Acts 15 and the Mishnah tractate Keritot. For Jews at the time of Christ the ingestion of blood resonated with various theological significances. We re-read John 6, applying as hermeneutical preunderstandings these theological significances. Under this interpretive rubric Jesus’ call to drink his blood, though radical, becomes both explicable and legitimate. John’s appeal is not to the literal eating of Jesus’ flesh and blood per se, but to those theological categories attached to literal eating which originate with the Torah blood prohibitions. Jesus, as a life-giving flesh-gift to the world, to be eaten with the blood, embodies the very presuppositions that originally prohibited blood; hence, “drinking” Jesus’ blood now fulfils that gracious reality which avoiding blood earlier testified to.

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  • Product development and thermal processing of squid and beef patties

    Nyhof, Fiona Jessie (2015)

    Masters thesis
    University of Otago

    The objectives of this thesis were to develop formulations and processing specifications for two types of cooked meat patties made with novel mixtures of squid and beef, and to design and verify a safe thermal processing regime that could be achieved under the available manufacturing conditions. Locally sourced Arrow Squid (Nototodarus sloanii) was trialled for process suitability in patty mixtures. Lower cost squid fins were unsuitable due to presence of skin pigments causing pink discoloration and the presence of hard textured fragments of squid pen material. Second grade frozen skinned squid tubes with uniform white colour and absence of pen were selected and used in formulations. Two types of cooked squid and beef patty products were developed: Squid and Beef Nuggets were produced by mixing together ground beef and ground squid tubes with other ingredients and forming into slightly oval shaped pieces (nuggets). Product dimensions were approximately 55mm x 40mm x 15mm thick and 24g per piece. The formulation was composed of ground squid tubes (39.0%), ground beef (23.8%) and a mixture of other non-meat ingredients (37.2%). Squid and Beef Bites were produced by co-extruding an outer casing mixture of ground squid tubes and other ingredients with an inner filling of ground beef patty mixture. The Bites were co-extruded on a Rheon forming machine and formed into bite sized pieces. Product dimensions were approximately 60mm x 60mm x 23mm thick and 60g per piece. The formulation was composed of ground squid tubes (44.9%), ground beef (21.2%) and other non-meat ingredients (33.9%). Both Nuggets and Bites were cooked on an electrically heated continuous contact belt grill cooker. Cooking was followed immediately by cooling and individually quick freezing the Nuggets or Bites in a blast spiral freezer. Products were packed as free flow pieces in polyethylene lined cardboard boxes and stored frozen below -18 ºC. A consumer acceptance study was conducted with 85 consumers. The squid and beef Nuggets and Bites were evaluated after reheating for overall liking, appearance, smell, texture and taste. A 90mm anchored line scale (where 1 = dislike extremely and 9 = like extremely) was used to rate the products. The mean overall liking scores for Bites and Nuggets were 6.63±SD2.48 and 5.9±SD2.02 respectively. A Student t-test determined there was a significant difference at the 95% confidence level for overall liking. Similar ratings were found for other attributes in the test, with appearance scoring higher for the Bites than for the Nuggets. The results indicated a ‘like slightly’ response. Further analysis of the distribution frequency of the scores revealed 69.2% of respondents rated Bites with scores of 6 or higher on the scale, while 50.6% rated Nuggets with scores of 6 or higher. This was considered a reasonable level of liking for the novel products with the Bites being slightly more preferred than Nuggets. Nutritionally, the squid and beef formulations had a low fat content of 4 - 6%, protein content of 14-15% and carbohydrate content of 9-11%. Squid and beef mixtures were found to have low cooking losses (not more than 5%). Costing analysis showed that wholesale prices for the Bites and Nuggets compared favourably with other frozen food service products. Bites and Nuggets were estimated to wholesale for around $7/kg while other available frozen convenience seafood products wholesale prices were found to be between $7.50/kg for ‘crab and fish bites’ to $ 11.25/kg for seafood finger food. Despite the positive competitive position of the indicative wholesale costings for the squid and beef products, the second grade squid tube raw material priced at $4.50/Kg was expensive for use in patty products, especially when compared to the cost of beef trimmings which ranged from $1.75/kg for fatty grade to $3.00/kg for lean grade. Optimization for cost reduction purposes was recommended. A safe thermal regime specifically designed for the squid and beef mixture used in the Nuggets was determined. Thermal death time (TDT) experiments were conducted to determine D values for Listeria spp. in the Nugget mixture. Listeria was selected because it had been detected on the raw material and because it is reported to have higher heat resistance than other pathogens of concern in meat patties, such as E.coli and Salmonella spp. Thermal inactivation of Listeria therefore is indicative of destruction of other pathogenic microorganisms. The D60 value determined for L.monocytogenes in the Nugget mixture was 6.14 minutes and the z value was 6.16 ºC. The values obtained for D60 and z in the Nugget mixture concurred with a typical range reported in the scientific literature for 11 different meat products. Based on the results of the TDT experiments, the thermal regime was specified for the safe processing of squid and beef patties as 69.4οC for a minimum of 97 seconds. This regime was sufficient to provide a 9.0-D thermal reduction treatment. A verification trial conducted under factory processing conditions with a variety of meat patty products confirmed the required 9.0-D thermal regime for Listeria spp. was achievable. A process capability index (Cp) for the critical end-point core temperature achieved during patty manufacturing using the continuous belt grill cooker was calculated using data from a previous study. The resulting Cp was found to be unacceptably low at 0.44. Consequently, a wide tolerance for patty endpoint core temperatures for the squid and beef products was specified at 75 ºC ± 6 ºC. A major source of variability associated with the belt grill cooker was identified and it was recommended that the process capability be re-determined after problem rectification. A Cp of 1.33 or higher was recommended which would enable tighter temperature tolerances to be specified. Formulations for two new pre-cooked frozen squid and beef patty products, design and verification of a safe thermal process for the patties and improved understanding of the performance aspects of a belt grill cooker’s thermal processing capability were the technical achievements resulting from this project. Further research into how to lower the cost and investigate how the composition and functional properties of Arrow Squid (Nototodarus sloanii) could be utilized in further processed meat product mixtures was recommended.

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  • Exceptional Choices? A Discursive Examination of Abortion Discourses in New Zealand

    Leask, Marita (2015)

    Masters thesis
    University of Otago

    While abortion discourses are often understood in terms of the opposing poles of pro-choice and pro-life, these labels belie the complexity of substantive understandings of abortion. This thesis examines dominant discourses of abortion in New Zealand through analysing legal, media and televisual discourses and qualitative interviews with fifteen women. Participants’ understandings of abortion were complex, at times contradictory and resisted easy delineation into cohesive positions. Nonetheless, the majority of participants understood abortion to be only legitimate in exceptional circumstances such as in cases where maternal health is at risk or the pregnancy is the result of rape. An analysis of such exceptionalism suggests that the exception proves the rule. Thus deeming some abortions legitimate reinscribes the fundamental point that abortion is illegitimate. Compounding the negative view of abortion germane in the exceptionalist framework, abortion was also normatively understood to be traumatic by several participants. Other participants resisted the idea that abortion is aberrant and immoral and instead saw abortion as an ordinary yet important healthcare decision. Critically examining dominant discourses of abortion as negative, harmful and exceptional allows for refocusing abortion as an ordinary yet vital part of women’s experiences of reproduction. I argue that abortion should be understood as an ordinary and legitimate part of women’s lives and not as an exceptional choice.

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  • Management ownership and firm value revisited

    Daniell, Mark James (2000)

    Masters thesis
    University of Otago

    The relationship between management ownership and firm value is investigated in an attempt to reconcile the conflicting findings in Morck, Shleifer and Vishny (1988) and McConnell and Servaes (1990) using a sample of Fortune 500 firms and two commonly used ownership sources. The findings support the quadratic form of McConnell and Servaes, suggesting that firm value increases to a maximum at around 25 to 35 percent management ownership, then decreases for management ownership levels beyond this point.

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  • Lineages of Indian democracy: A response to Octavio Paz's Vislumbres de la India

    O'Connor, Holly Frieda (2014)

    Masters thesis
    University of Otago

    Paz identifies democracy as the only viable form of modern governance. But the concept of democracy in India has two distinct meanings: political society considers it in terms of the right to vote and the rule of law, while civil society defines it as a series of solidarity rights. Political conflict arises from opposition between different social sectors. But the division between civil society and the state is not so simplistic. It is also characterised by ethnic, cultural, political and religious divisions within. In response to the political violence that marks India's modern democracy, Paz in his Vislumbres de la India asks 'En que tiempo vivimos?' To attain peace, Paz considers a political order with its roots in the present. He also considers that a democracy which is not secular is not really a democracy. However, secularism means much more than the separation of politics and religion. It should also extend equal protection to all religions under the auspices of the state. This has interesting implications in terms of Hindu Muslim conflict in a democracy in which Hindu and nationalism have become synonymous. Paz also asserts that politics and morality are inseparable. One salient feature of democracy is that it promises equal rights to all citizens. This promise intersects with the question of universal rights. In a society as diverse and multicultural as India, there is an inherent danger in a discourse which proclaims the idea of universality with regard to rights. In light of this problematic, rights are complicated both by political and temporal contexts. But nor are rights simply the result of purely legal interventions. They are a response to social inequalities and exist in many forms, not all of which are referent to the law. To return to Paz's question, this essay asks what, in the present, pertains to a universal conception of rights? Can rights be conceived as universal, or are they necessarily contingent on social and temporal contexts?

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  • It all starts in the gut: The intestinal immune cell infiltrate in inflammatory bowel disease and ankylosing spondylitis

    Dunn, Elliott Thomas James (2014)

    Masters thesis
    University of Otago

    Inflammatory Bowel Disease (IBD) and Ankylosing Spondylitis (AS) have epidemiological, symptomatic and genetic overlap. Many people with IBD develop AS and vice versa, and both groups of patients exhibit pathological inflammation. This suggests a role for the immune system in linking the diseases. The aim of this study was to investigate the balance of macrophage and T cell subsets in the intestinal mucosa of people with IBD, AS, and healthy people. This was to improve our understanding of how innate and adaptive immune responses contribute to pathogenesis of inflammatory gut disorders. I hypothesised that genetic defects of the innate immune system, in people with IBD and AS, cause a shift in the proportion of macrophage subsets. Further, this would lead to chronic intestinal inflammation, characterised by IL-17 and IFNγ producing T cells. Methods were developed to identify complex T cell and macrophage subsets within human intestinal tissue. Multi-parametric flow cytometry was used to establish these methods, which were subsequently extended. For T cells, additional cytokines with relevance to IBD and AS were incorporated. This allowed detection of an increased frequency of T cells in the terminal ileum compared to the colon. For macrophages, additional phenotypic markers were incorporated to identify gut-specific macrophage subsets. Intestinal T cell profiles of people with CD, and AS were compared to those of healthy people. This revealed that people with inactive CD, and AS had an intermediate T cell phenotype between actively inflamed tissue and healthy tissue. This profile was characterised by differences in frequencies of IL-2 producing T cells and regulatory T cells. IL-17 producing T cells and regulatory T cells were increased in inflamed tissue compared to healthy, while IFNγ producing T cells were not. These immunological data, in combination with genetic studies, further elucidate how the immune system may be altered by genetic polymorphisms that lead to the development and maintenance of inflammatory diseases, such as IBD and AS. Based on the data presented here, I hypothesise that combinations of multiple genetic polymorphisms lower the threshold for development of intestinal inflammation, which leads to initiation of inflammatory diseases, including IBD and AS.

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  • The Role of Retinoic Acid as a Morphogenic Agent in Xenopus laevis Early Axis Formation and Limb Development

    McNally, John Farrel (2014)

    Masters thesis
    University of Otago

    Retinoic acid (RA) is a morphogen that functions as a patterning agent in vertebrate development. It is able to pattern tissue due to variation in its bioavailability along a gradient that is generated and regulated by controlling the synthesis and degradation of RA. Its role can also be effected due to the presence of different receptors. The use of RA as a morphogenic agent has been observed as being vital to developmental processes, such as forming the anteroposterior axis in vertebrates and limb development. Analysis of the transcriptome of the developing limb, divided into three sections along the proximal-distal axis, showed varied levels of expression of over 1000 genes. Of these 15 were investigated including two variants of the protein family CYP26, one of which had not been characterized and cyp26c1, which had not been investigated for a role in limb development. The novel sequence was compared to known sequences and was identified as being highly similar to cyp26a1, thus designated cyp26a2. Phylogenetic analysis shown it had only recently diverged, which fits with the recent whole genome duplication event in Xenopus laevis. Analysis showed that the cyp26a2 variant mapped to a unique genomic locus which no confirming it to be a novel gene. Investigating the synteny of the CYP26 loci in the areas immediately around the genes shows high levels of conservation of neighboring sequence as well showing that cyp26a1 and cyp26c1 were evolutionarily linked at the same locus in vertebrates. Both cyp26a2 and cyp26c1 were successfully cloned and their expression patterns ascertained. The novel variant cyp26a2 exhibited expression in regions its paralogue was expressed in as well as novel regions. To investigate potential RA regulated of key genes tadpoles were immersed in a solution containing RA or citral, an antagonist of RA, and their expression profiles examined. This showed alterations in expression in 13 of the 15 genes studied. Next limb expression was studied to get a more accurate image of the expression usually present and this showed that the genes were often localized to specific regions of the limb. The cyp26a2 variant was expressed at the base and had a pattern distinct from its paralogue cyp26a1 which is expressed in the distal end of the limb (McEwan, Lynch et al. 2011) indicating a divergence in function. Cyp26c1 was also confirmed as being expressed in the developing limb, first in the AER before being restricted to the tips of the developing digits and the lateral epidermis of the zeugopod. Localized response to RA was tested by inserting beads saturated in RA into the developing limb. To investigate whether this technique could enable the examination of short term genetic responses to localized RA genes the expression patterns of genes that were previously determined to be affected by RA were probed using in situ hybridization. Several of the genes investigated showed an up regulation in response to RA. This indicates the technique can probe genetic responses to RA.

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