3,588 results for 2000, Doctoral

  • The free child health care scheme : implications for New Zealand general practice

    Dovey, Susan May (2002)

    Doctoral thesis
    University of Otago

    xv, 260 leaves :ill. ; 30 cm. Includes bibliographical references.

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  • Habitats and macroinvertebrate fauna of the reef-top of Rarotonga, Cook Islands : implications for fisheries and conservation management

    Drumm, Darrin Jared (2005)

    Doctoral thesis
    University of Otago

    xiii, 173, [6] leaves :ill. ; 30 cm. Includes bibliographical references. University of Otago department: Marine Science. "December 2004."

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  • Open population capture-recapture models and diabetes in Otago

    Cameron, Claire (2009)

    Doctoral thesis
    University of Otago

    xiv, 207 leaves :ill., ; 30 cm Includes bibliographical references. University of Otago department: Mathematics and Statistics

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  • Care ethics and brain injury

    Butler, Mary (2008)

    Doctoral thesis
    University of Otago

    It is generally supposed that a supportive family can have an influence on outcomes for an adult with severe brain injury, but there is very little known about what effective families actually do. In this research the families of five such individuals were involved in an ethnographic project that lasted for one year. The literature review brought together insights from brain injury, care ethics, disability studies and anthropology. These insights were combined with a process of reflective equilibrium that was applied to the ethnographic material in order to determine the ethics of the carers. Ethics of care in this setting was conceived of as a positive practice ethic, rather than as a series of negative conundrums posed by the brain injury. The practice ethic shared by carers meant that they all conceived of the need created by brain injury in humanistic terms, rather than in terms of pathology. Carers demonstrated virtues appropriate to their practice as they helped the adult with brain injury to connect with aspects of ordinary life. The best outcomes for the adult with brain injury included being able to engage in productive activity and to make a place in the world. These outcomes could only be achieved with due regard for their safety and subsistence. The practice ethic of carers was demonstrated in the skills and concern that ensured a satisfactory outcome for the adult with brain injury. This research is a departure from recent research about families affected by brain injury, which has focused on the burden involved in care. An examination of what carers achieve suggests that burden may be associated with the development of caring practice. The transformative capacity of care, for both the carer and the adult with brain injury, is emphasized. However contextual factors, such as adequate compensation, are connected to the capacity of the carer to engage in good practice and these are explored also in this thesis. In particular, relevant aspects of the relationship between families and the Accident Compensation Corporation are explored.

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  • Thermophiles and fouling deposits in milk powder plants : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Engineering and Technology at Massey University, Palmerston North, New Zealand

    Hinton, Andrew Richard (2003)

    Doctoral thesis
    Massey University

    Fouling deposits were suspected of playing a pivotal role in the thermophile contamination problem experienced in the dairy industry during milk powder manufacture. The objective of this work was to investigate thermophile growth and develop an understanding of how fouling deposits affect thermophile contamination in milk powder plants. Pilot plant and laboratory scale studies were carried out investigating: The release of thermophiles from fouled and un-fouled surfaces; The survival of thermophiles in fouling during cleaning: The rate of re-contamination of thermal equipment after incomplete cleaning; and the adhesion of thermophiles to fouled and clean stainless steel. Thermophile contamination from the pilot plant equipment was also modelled mathematically. The bulk milk thermophile contamination from sanitised fouled and un-fouled surfaces was found to be not significantly different, showing that fouling deposits by themselves do not increase the steady state amount of bulk contamination and that the more important factor is the amount of surface area available for colonisation within the temperature growth range of the thermophiles. Milk fouling layers provided much greater protection against cleaning than that of biofilms alone. Thermophiles that survive cleaning or greater initial thermophile concentrations in the raw milk were shown to reduce the plant production time available before concentrations of thermophiles in the bulk milk became excessive (>1x10 6 cfu.ml-1). Therefore, cleaning procedures in milk powder plants need to remove or destroy all traces of thermophiles to allow the maximum possible run length. It is similarly important to obtain raw milk with the lowest possible thermophile load before processing. During adhesion studies, the number of thermophilic bacteria adhering to stainless steel surfaces increased with bulk cell concentration and increasing contact time for adhesion. The adhesion rate of thermophiles to whole milk fouling layers was found to be around ten times higher than the adhesion rate to stainless steel. Steady state modelling provided a quick estimate of the level of bulk milk contamination that can be expected, however it was dependent on obtaining accurate measurements of the surface numbers. Since surface numbers were underestimated by approximately a decade using techniques that dislodged but did not enumerate loosely adhered cells, the model under predicted the bulk milk contamination. Unsteady state modelling predicted the trends observed in the experimental data and provided reasonable estimates of the bulk contamination that can be expected over time from the pilot plant. Predictions from the model after changes in key parameters provide an insight to the magnitude of any reduction in contamination that can be made. The results of this work have demonstrated that thermopile contamination during dairy processing can be minimised through: Re/design operating equipment to minimise the residence time of the product in the range of 40-70°C. Minimising the contact surface area of thermal equipment by use of alternative direct heating technologies. Minimising fouling by management of milk quality, optimising processing conditions, hygienic design of the plant equipment and ensuring the product mix is suited to the plant. Ensuring that the plant is thoroughly clean at the commencement of each run through attention to equipment design and optimisation of cleaning procedures.

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  • Progress towards development of a genetically modified strain of the Australia sheep blowfly Lucilia cuprina suitable for a sterile release program : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Molecular Genetics at Massey University, Palmerston North, New Zealand

    Li, Xuelei (2002)

    Doctoral thesis
    Massey University

    The sterile insect technique (SIT) is concerned with the mass-rearing and release of sterilized insects which mate with "wild-type" females in the field, producing no viable offspring. The aim of this study was to use genetic engineering methods to make a strain of the Australia sheep blowfly Lucilia cuprina which is suitable for an area-wide sterile-male release program. The main objectives were: development of an efficient germline transformation system for introducing a target gene into Lucilia and development of an inducible female killing system to produce a male only population. The piggyBac and Minos transposons were evaluated as transformation vectors for L. cuprina. Firstly, Drosophila melanogaster was used as a model system to determine if the frequency of both inter-plasmid transposition and germ-line transformation increases with the level of expression of the piggyBac transposase. Expression of the piggyBac transposase gene was controlled with either the α1-tubulin, hsp83 or hsp70 promoter, which have strong, intermediate and low constitutive activity respectively. The results show that the frequency of piggyBac-mediated germ-line transformation does increase with the level of expression of the transposase. In contrast, there does not appear to be a simple correlation between the level of expression the transposase and the frequency of transposition measured using an inter-plasmid transposition assay. This suggests that this widely used assay may not necessarily predict which is the best "helper" plasmid for germ-line transformation. Secondly, inter-plasmid transposition assays have shown that both piggyBac and Minos transposases are active in blowfly embryos. Thirdly, Drosophila eye color genes and the enhanced green fluorescent protein (EGFP) gene were tested as potential markers for identifying transgenic flies. The most promising marker based on transient expression appears to be EGFP driven by the Drosophila polyubiquitin gene promoter (pUb-EGFP). Fourthly, blowfly embryos were coinjected with the piggyBac helper driven by the D. melanogaster hsp70 promoter and the PUbnlsEGFP marker gene. Two transgenic L. cuprina lines were isolated and characterised by Southern DNA hybridisation analysis and inverse PCR. The transformation frequency was 1.4 to 1.9%. Of the two transformant lines obtained, one had a single copy of the transgene and the other most likely has four copies. This is the first report of germ line transformation of L. cuprina. A tetracycline regulated inducible expression system was adopted to develop a controllable female-killing genetic system based on the D. melanogaster msl2 gene. One component of the system is the tetracycline dependent transactivator (tTA) gene controlled by a constitutive promoter. The other (tetO-msl2) is the msl2 coding region controlled with a promoter bearing seven copies of the tetracycline operator (tetO) sequence. Female D. melanogaster carrying both a promoter-tTA and tetO-msl2 gene constructs would be predicted to die in the absence of tetracycline due to expression of msl2. In this study several promoter-tTA constructs were developed including WH-arm which uses the constitutive armadillo promoter. Drosophila carring both WH-arm and tetO-lacZ transgenes were shown by spectrophotometric and histochemical staining assays to express β-galactosidase but only if raised on media that lacked tetracycline. There was a significant decrease in viability of females carrying both WH-arm and tetO-msl2 gene constructs raised on media lacking tetracycline. However lethality was not 100%. Assembly of the MSL complex on female X chromosomes (due to expression of msl2) was confirmed by immuno staining of polytene chromosomes with anti-MSL3 antibody. Thus it appears that induction of 100% female lethality will require higher levels of msl2 expression than obtained with the WH-arm/tetO-msl2 system for controlling female viability in transgenic Lucilia.

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  • The pattern and regulation of mammary gland development during fetal life in sheep : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand

    Jenkinson, Catriona Margaret Christie (2003)

    Doctoral thesis
    Massey University

    The production of colostrum and milk in sufficient amounts is essential for the survival of the neonate. Although there is limited data to indicate that the extent of fetal mammary development is essential to subsequent milk production, the secretory epithelial cells that proliferate during pregnancy do so on the epithelial ducts that have developed during prenatal life. Thus any reduction in duct development may ultimately impact on secretory cell mass and hence the capacity of the adult gland to produce milk. A series of studies were carried out to establish patterns of fetal mammary gland development between male and female sheep and to identify factors that may be involved in the regulation/mediation of growth and differentiation, and that may contribute to the sexual dimorphism of the gland. In addition, mammary gland development was measured in fetuses from ewes in which the maternal environment was altered by hormones, nutrition or pre-lamb shearing. The sequence of events in the development of the mammary gland of the fetal sheep was similar to that described for cattle. Sexual dimorphism in the ovine gland became pronounced during the formation of secondary ducts and was especially evident during the development of the fat pad where adipose tissue was far less abundant from the outset in the male. In terms of epithelial development, total duct area was similar in males and females up until day 120 of fetal age. Between days 120 and 140 of fetal age, total duct area doubled in females while the interval between day 140 and three weeks of postnatal age witnessed a four- to five-fold increase in the size of the duct system. Conversely, the male gland failed to progress beyond that observed at day 120. The sex differences observed in the histomorphogenesis of the gland were reflected in a relative growth analysis of mammary development. The growth of the mammary gland in the female followed the general development of the fetus, while in the male, mammary growth exhibited negative allometry from day 80 to 140 of fetal age. Further experiments investigated factors that may be involved in the regulation of epithelial and mesenchymal growth within the fetal mammary gland. Receptors for androgen and oestrogen were localised in the mammary epithelial and mesenchymal cells of both sexes. An association between the localisation of androgen receptors (AR) and the divergence in the pattern of mammary development between males and females suggested the involvement of androgens in the sexual dimorphism of the gland. In support of this suggestion was the observation of a similar pattern of mammogenesis and AR immunoreactivity in the mammary glands of female fetuses whose dams were injected with testosterone during early gestation. Insulin-like growth factor-I receptor (IGF-IR) followed a similar pattern of immunoreactivity to AR in the mammary tissue of the male indicating that the suppression of mammary growth may be mediated by IGFs. IGF-IR immunoreactivity tended to increase in both the epithelial and mesenchymal cells of the female mammary gland as gestation progressed. An abundance of IGF-IR in the developing fat pad of the female gland suggested a role for locally derived IGFs in stimulating adipose tissue growth and hence, the continued proliferation and morphogenesis of epithelial cells. The final study demonstrated that a low plane of maternal nutrition throughout pregnancy was detrimental to development of the fetal mammary gland and hence, its future capacity to produce milk. In terms of total duct area, fetal mammary growth was more than two-fold greater in fetuses whose dams were exposed to a high plane of nutrition throughout pregnancy than in those fetuses whose dams remained at maintenance. This substantial difference in the amount of epithelial tissue present occurred without any significant effect on fetal or gland weights. Moreover, the increase in total duct area associated with a higher plane of maternal nutrition closely mirrored the increase in the intensity of IGF-IR immunostaining in the epithelial cells. In conclusion, these results provide indirect evidence that inhibition of mammary gland growth in the fetal male sheep is dependent on its exposure to testosterone and may involve mediation by IGF-I. Oestrogens may act directly or indirectly, mediated by oestrogen-induced IGFs from the mesenchymal cells, to stimulate epithelial cell differentiation and proliferation in the mammary gland of the fetal female sheep. Furthermore, strong evidence indicates that the ewe is able to influence mammary development in her female offspring in utero, which may eventually affect their potential to produce milk.

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  • Studies on the binding of iron and zinc to milk protein products : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology, Riddet Centre and Institute of Food, Nutrition and Human Health

    Sugiarto, Maya Wulansari (2004)

    Doctoral thesis
    Massey University

    The principal objective of this study was to characterize the binding of iron and zinc to three commercial milk protein products; namely sodium caseinate, whey protein isolate (WPI) and milk protein concentrate (MPC). The mineral-protein mixtures were prepared by mixing either iron (FeSO4.7H2O) or zinc (ZnSO4.7H2O) at a range of concentrations with 1% protein solutions (e.g. sodium caseinate), in 50 mM HEPES buffer at pH 6.6. The mineral-protein mixtures were then centrifuged (10,800 g, 20 min) to separate the soluble protein and soluble minerals from the insoluble protein and insoluble minerals. The supernatant, which contained the soluble fractions, was carefully removed and passed through an ultrafiltration membrane to separate "free" minerals from the minerals bound to the soluble proteins. Under the experimental conditions used in the study, aqueous solutions of ferrous sulphate were relatively insoluble. This was due mainly to the oxidation of ferrous sulphate to the insoluble ferric hydroxide. The addition of a 1% sodium caseinate solution markedly improved the solubility of ferrous sulphate due to the binding of iron to the caseins. The casein molecules were able to bind up to 8 moles Fe/mole protein. Addition of iron above a certain critical concentration (approximately 4 mM) caused the aggregation and precipitation of casein molecules. The loss of solubility was due mainly to the neutralisation of the negative charges on the casein molecules by iron with a consequent decrease in the electrostatic repulsions between the protein molecules. In contrast to the behaviour of the sodium caseinate, the interactions of iron with the whey protein molecules in WPI did not cause significant precipitation of the iron-WPI mixtures. Whey proteins remained soluble up to a concentration of 20 mM added iron and were able to bind up to approximately 7 moles Fe/mole of protein. Analysis of the binding curves by Scatchard plots showed that sodium caseinate has a higher binding affinity for iron (log Kapp = 5.3) than WPI (log Kapp = 3.6). This confirmed the experimental observation that in sodium caseinate solutions, up to the critical concentration of iron, virtually all iron was bound to the protein molecules whereas in WPI solutions, a small amount of free iron was present. The strong affinity for iron shown by the casein molecules is due mainly to the presence of clustered phosphoserine residues, which are absent in whey proteins. The binding characteristics of iron to MPC were broadly similar to those for sodium caseinate. However, soluble MPC was able to bind greater amount of iron (45 mg Fe/g protein) than soluble sodium caseinate (20 mg Fe/g protein). In MPC, casein molecules exist in the micellar form and iron was likely to be bound to both the caseins and the colloidal calcium phosphate, probably displacing calcium ions in the process. The binding properties of proteins were significantly affected by changes in pH. As the pH was decreased from about 6.5 to 5.0, there was a marked decrease in the ability of proteins to bind cations. For example, the amount of iron bound to WPI decreased from approximately 8 to 1 mg Fe/g soluble protein as the pH dropped from 6.5 to 5.0. This decrease was presumably due to the change in the ionisation state of the negatively charged residues. In the case of sodium caseinate and MPC, the situation was complicated by the marked loss of protein solubility at pH values ≤ 5.0. The binding characteristics of zinc to the three milk protein products were broadly similar to those for iron. For sodium caseinate and MPC, there was a critical concentration of added zinc above which proteins lost solubility. Sodium caseinate showed a greater binding affinity for zinc than WPI (Log Kapp values were 4.8 and 3.3 respectively), while MPC was able to bind more zinc (25 mg Zn/g protein) than sodium caseinate (14 mg Zn/g protein). However, there was one distinctive difference between the binding behaviour of iron and zinc. In the case of WPI, addition of zinc caused precipitation of whey proteins at a concentration above 4 mM added zinc. This was due to the specific binding sites for zinc in the α-lactalbumin fractions. Oxidation tests, using linoleic acid as the substrate, showed that iron-protein mixtures were able to markedly suppress the rate of oxidation compared to free iron. Among the iron-protein mixtures, iron-sodium caseinate and iron-MPC mixtures suppressed the oxidation rate to a greater extent than iron-WPI mixtures. In iron-sodium caseinate and iron-MPC mixtures, the iron was completely bound to the protein whereas in iron-WPI mixtures, there was still a small amount of unbound iron, which could cause oxidation. The data obtained from this study will provide valuable information for the production of mineral-protein complexes with good functional properties, which could be used as a source of ingredients in other food products.

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  • Women, politics and the media : the 1999 New Zealand general election : a thesis presented in partial fulfilment of the requirements for the degree of PhD in Communication & Journalism at Massey University, Palmerston North, New Zealand

    Fountaine, Susan Lyndsey (2002)

    Doctoral thesis
    Massey University

    New Zealand's shift to a Mixed Member Proportional (MMP) system of government contained a two-fold promise for women. Explicitly, there was the prospect of increased electoral diversity, meaning more women in Parliament, and implicitly, there was a promise of better political reporting and therefore qualitatively better coverage of women. The country's second proportional representation election campaign, in 1999, appeared to deliver on these promises. The 1999 General Election was historically significant because it featured two women - incumbent Jenny Shipley and Labour leader Helen Clark - contesting the role of Prime Minister. Female politicians also featured in important electorate races, and made the headlines during New Zealand First's gender-based list controversy. According to one media commentator, women determined the outcome, dominated the news and changed the nature of the campaign (Harris, 2000). However, popular opinion that women influenced the character of the campaign, and especially that they dominated the campaign, is in contrast to empirical research, from around the world, which has consistently suggested women politicians receive less news coverage, are "framed" or packaged in stereotypically feminine ways, and ultimately disadvantaged by traditional news coverage (e.g. Bathla, 1998; Braden, 1996; Gidengil & Everitt, 1999; Herzog, 1998; Norris, 1997c; van Acker, 1999). Therefore, the main aim of this study was to explore, using a combination of corroborative methodologies, how and why the news media covered female politicians during the 1999 election campaign. Three methodologies (content analysis, qualitative interviews, and a case study), and a framing typology, were employed. Content and frame analysis showed that female politicians were used as news subjects to a comparable, if not better, extent than men but were marginalised as political news sources. In other words, there was a tendency for women to be talked about, rather than talked to. This reflects dominant news structures and, in some cases, the women's own approach to self-promotion. It was also revealed that female politicians were subjected to more polarised media coverage, influenced by status, incumbency and context, and again, partly a result of their own positioning. There were significant differences in media coverage of men and women, but framing of political news did little to advance women's perspectives, suggesting election campaigns that ostensibly feature women are not necessarily of a different nature. Overall, these results suggest a blurring of the traditional "public/private" dichotomy, as an outcome of changes in the media (such as the contemporary trends toward personalisation and "celebrification") and women's campaigning. Gender remains a factor in the presentation and interpretation of political women, by the news media (which, for example, portrayed the female leaders as Xena princesses) and by the women themselves (for example, Shipley portrayed herself as a mother figure). To some extent, there appears to have been a maturing of political journalism about women but it is too soon to tell if the shift to MMP has resulted in any significant longterm change for female politicians. However, this unique study, in examining the media-politics-gender nexus in the 1999 General Election campaign, focuses attention on the two-fold promise of MMP for women, and explores the extent to which the new political system and the media have begun to deliver. On a practical level, the thesis concludes that it is important to encourage female politicians to work within, and use the current system to their advantage. However, it also urges researchers to take a critical approach to exploring the systemic socialisation and pervasive news structures, processes and values that contribute to women's ongoing political marginalisation. Finally, the thesis considers the wider implications for women, the news media, and the electoral system.

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  • Bacterial attachment to meat surfaces : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Palmerston North, New Zealand

    Narendran, Valarmathi (2003)

    Doctoral thesis
    Massey University

    The aim of this study was to optimise the hygienic efficiency of slaughter and dressing operations. Three strategic approaches, namely reducing and removing or killing the bacteria attached to meat surfaces, were considered. The second option of removal was selected for development, as current technology inevitably results in bacterial contamination, while killing bacteria on meat surfaces requires drastic treatments that may adversely affect quality parameters. The initial attachment mechanism between bacteria and the carcass surface (reversible attachment) was studied using the collagen film model system. Bacterial attachment to the collagen model was compared with attachment to cut beef muscle and uncut beef muscle using viable count procedure. Scanning electron microscopy and direct microscopic count procedure using an epifluorescence microscope was also developed using both collagen films mounted on microscope slides and collagen coated microscope slides. The collagen film viable count system was the method selected to model bacterial attachment to meat because of ease and consistency of quantification. There was no positive correlation between attachment and many bacterial cell surface factors such as charge, hydrophobicity, protein and polysaccharide surface molecules. Different eluents were used to identify the principal component interfering with single attachment mechanisms on electrostatic interaction and hydrophobic interaction chromatographic columns and on collagen film. Three components interfering with the isolated attachment mechanisms were identified. They were Tween, sodium chloride (NaCl) and mannose. Further column studies indicated that cell surface proteins play a more important role in cell surface negative charge and hydrophobicity than do surface polysaccharides. A wash solution was formulated using the components Tween, NaCl and mannose to reverse what were believed to be the major attachment mechanisms. Further trials with Tween, NaCl and mannose and increasing their concentrations and the application of increased vigorous rinsing also proved ineffective for washing the cells from meat surfaces. This result also supports the hypothesis that bacterial attachment to meat surface is very complex and multifactorial. Elution studies using 10 % Tri sodium orthophosphate pH 12.0 killed the cells rather than removing them and further work will be directed towards the killing.

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  • The self-perceived role of Christian chaplains in New Zealand state schools : a thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Religious Studies at Massey University

    Yapp, Maria Madelene (2003)

    Doctoral thesis
    Massey University

    State school chaplaincy is a recent phenomenon in New Zealand state schools. It was introduced in the 1980s by the Churches Education Commission (CEC), after the Bible in School programmes, as a voluntary service to care for children in state schools. Currently CEC promotes that a chaplain is a "confidential ear" and "a caring trusted friend" and states that chaplaincy "supports the pastoral care networks in New Zealand schools for students, staff, parents and care-givers and Boards of Trustees". However, definition of the key terms has not been provided and no research has determined what chaplains do. This thesis explores the work of state school chaplains, by participant observation, questionnaires, and interviews, examining who these chaplains are, the nature of Chaplaincy Assessing Resourcing Equipping (C.A.R.E.) courses, and how chaplains "support the pastoral networks of New Zealand schools". Results indicate that they, as a group, display an autonomy, independence, and freedom not clearly discernible in their job descriptions of "confidential listening ears" and "caring trusted friends". They seek the advantages of both remaining apart from and a part of the school establishment. They support state schools, by working under the guidance of the school staff and acting as independent workers and consultants. As "confidential listening ears", they have found their way from school playgrounds to staff meetings. The autonomy chaplains claim may have derived from CEC's failure to provide clear operational definitions of the chaplaincy role, lack of adequate assessing and equipping at chaplaincy courses, and/or lack of sufficient monitoring and supervision on the job. Their extensive involvement in helping and caring for state schools, including evangelization, may have stemmed from the fact that they, as Christian helpers, want to act like Jesus or 'be Jesus'. The meaning of 'being Jesus' is explored by examining the idea of loving one's neighbours as oneself, the example of Jesus, and Jesus' account of the parable of The Good Samaritan. It is suggested that acting like Jesus or "being Jesus' includes not only helping but also evangelization. However, evangelizing in state schools contravenes CEC's recommendations. It is recommended that CEC clarify its intention for state school chaplaincy and consider both the appropriateness and intent of the use of the title 'chaplain', as well as provide precise operational definitions for the key terms of the chaplaincy roles.

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  • Antimicrobial activity of functional food ingredients focusing on manuka honey action against Escherichia coli : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering and Technology at Massey University, Auckland, New Zealand

    Rosendale, Douglas Ian (2009)

    Doctoral thesis
    Massey University

    The goal of this research was to identify functional food ingredients/ingredient combinations able to manage the growth of intestinal microorganisms, and to elucidate the mechanisms of action of the ingredient(s). By developing a high-throughput in vitro microbial growth assay, a variety of preselected ingredients were screened against a panel of bacteria. Manuka honey UMF(TM) 20+ and BroccoSprouts(R) were identified as the most effective at managing microbial growth, alone and in combination. Manuka honey was particularly effective at increasing probiotic growth and decreasing pathogen growth. Testing of these two ingredients progressed to an animal feeding trial. Here, contrary to the in vitro results, it was found that no significant in vivo effects were observed. All honeys are known to be antimicrobial by virtue of bee-derived hydrogen peroxide, honey sugar-derived osmotic effects, and the contribution of low pH and the other bioactive compounds present, hence their historical usage as an antiseptic wound dressing. The in vitro antimicrobial effect of manuka honey has currently been the subject of much investigation, primarily focusing on the Unique Manuka Factor (UMF), recently identified as methylglyoxal, a known antimicrobial agent. This work has taken the novel approach of examining the effects of all of the manuka honey antimicrobial constituents together against Escherichia coli, in order to fully establish the contribution of these factors to the observed in vitro antimicrobial effects. For the first time, it has been demonstrated that the in vitro antimicrobial activity of manuka honey is primarily due to a combination of osmotically active sugars and methylglyoxal, both in a dose-dependent manner, in a complex relationship with pH, aeration and other factors. Interestingly, the manuka honey was revealed to prevent the antimicrobial action of peroxide, and that whilst methylglyoxal prevented E. coli growth at the highest honey doses tested, at low concentrations the osmotically active sugars were the dominant growth-limiting factors. Contrary to the literature, it was discovered that methylglyoxal does not kill E. coli, but merely extended the lag phase of the organism. In conjunction with the lack of antimicrobial activity in vivo, this is a landmark discovery in the field of manuka honey research, as it implies that the value of manuka honey lies more towards wound dressing applications and gastric health than as a dietary supplement for intestinal health.

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  • The impact of traumatic and organizational stressors on New Zealand police recruits : a longitudinal investigation of psychological health and posttraumatic growth outcomes : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University Turitea Campus Aotearoa/New Zealand

    Huddleston, Lynne Mary (2002)

    Doctoral thesis
    Massey University

    Police officers face exposure to traumatic events due to the inherent nature of their profession. As well, as with the employees of any large organization, they are subjected to daily organizational events within their workplace (resource concerns, interactions with co-workers, administrative hassles). Very little is known as to the extent to which these organizational events moderate the development of traumatic stress outcomes. Investigations of police well-being have almost inevitably focused on negative work events and their pathogenic consequences. However, this study seeks to widen this pathogenic orientation by also considering the impact of positive daily work events (uplifts), and by evaluating a possible salutogenic outcome; the development of posttraumatic growth. A longitudinal methodology was utilized to establish baseline measures of traumatic event exposure (the TSS) and psychological well-being (the IES and the HSCL-21). All the 673 recruits who entered police college over one year were invited to participate in the study, and the 512 who completed the first questionnaire were reassessed one year later. The second questionnaire contained measures to assess the impact of the organizational environment (Uplifts and Hassles Scales), police traumatic events (a modified TSS), and posttraumatic growth outcomes (the PTGI). Parametric analyses and hierarchical multiple regression were used to evaluate the study hypotheses and post-hoc analyses investigated moderating effects. The recruits entered the police with high levels of prior traumatic event exposure, which, during the following year substantially increased. Psychological health remained in a robust condition, and psychological distress did not increase, although officers who experienced on-duty and multiple traumatic events had significantly higher traumatic stress than those who did not. Other important findings were that the organizational environment contributed to psychological distress outcomes, and post-hoc analyses indicated that this had an important interrelationship with traumatic stress outcomes as well. Organizational uplifts had a salutogenic effect upon physical health, and aided the development of posttraumatic growth following traumatic exposure. This study has supported the development of a synthesized research orientation that combines salutogenic as well as pathogenic research methodologies.

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  • Field and modelling studies of the effects of herbage allowance and maize grain feeding on animal performance in beef cattle finishing systems : a thesis in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand

    Machado, Claudio Fabián (2004)

    Doctoral thesis
    Massey University

    The objetive [sic] of the work described in this thesis was to develop a mathematical model designed as a tool for research intended to improve the efficiency of finishing systems for 1-2 year old beef cattle under intensive grazing mangement [sic] on sown pastures in Argentina. The work involved a) three experiments in Argentina carried out to define the effects of herbage allowance and maize grain supplementation on herbage intake and animal performance, b) one experiment in Argentina following a preliminary study in New Zealand of seasonal variation in the composition and nutritive value of intensively managed beef pastures, and c) an exercise to develop a model of beef cattle production incorporating modules dealing with aspects of pasture production and utiisation [sic], herbage intake and animal performance. The results from the series of short-term grazing studies showed consistency in the comparison of the effects of increasing herbage allowance and supplementation on herbage intake and animal LWG (Chapter 4). A method combining the use of n-alkane and 13C method proved to be accurate for quantitative estimates of herbage and maize grain intake, and allowed estimates of a substantial variation in individual maize grain intake (between 31 to 41 % CV) when animals are supplemented in groups. The substitution rate (SR) measured in these studies varied little across experiments or level of grain at a herbage DM allowance of 2.5 % LW d-1 (0.36 and 0.38 kg herbage DM per kg grain DM for Chapters 3 and 4 respectively). Increasing level of herbage DM allowance increased quadratically the SR from 0.38 to 0.83 and 0.87 kg herbage DM per kg grain DM. The n-alkane method was effective in providing estimates of diet digestibility. Different methods for estimating diet composition, such as microhistological evaluation of faeces, differences in nutrient and component selection indexes and n-alkanes were used in the initial grazing trial (Chapter 2) but they were not considered to be reliable and they were too laborious for continued use under field conditions. The outcome of the studies on seasonal variation in herbage quality initially was useful in establishing a database of the range of values observed, and in demonstrating their relative robustness, at least under conditions of good pasture management. In these studies, herbage nutritive value did not seem to be a limiting factor for growing beef cattle, at least in terms of the minimum observed content of metabolisable energy (10.8 MJ ME kg DM) or crude protein (17.3 % DM). Additionally, significant relationships were established between morphological and maturity estimates and herbage nutritional variables in a pasture under grazing conditions. These relationships showed promise for future use in the prediction of herbage nutritive value, but require further work. The model developed ("BeefSim"), represents the main biological dynamic processes of the target system of this thesis, together with additional management decision and financial estimates. It was shown that the model presents adequate flexibility and can be interrogated in terms of its response to different management conditions, scenarios and timeframes. Pasture management and grain feeding were controlled in an interactive management module responding to deviations in pasture conditions and animal liveweight from pre-determined targets. Two key outcomes of the model, liveweight gain and herbage intake were accurately predicted when compared against experimental information under different levels of herbage allowance and maize feeding. System comparisons developed with the model showed agreement with the literature, and maize grain feeding associated with the monitoring procedure demonstrated an effective use of grain in the system. The model provides a good biological basis for a holistic appraisal of the effects of "process technologies" such as grain feeding in beef cattle finishing systems, and will be developed further.

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  • Behaviour of fat globules and membrane proteins under different processing environments as related to milk powder manufacture : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology

    Ye, Aiqian (2003)

    Doctoral thesis
    Massey University

    The objective of the first part in this study was to gain a better understanding of the protein components of the milk fat globule membrane (MFGM). In the second part, the influence of processing factors on the fat globules and the MFGM during the manufacture of whole milk powder were examined. Relationships between the state of the MFGM in whole milk powders and their reconstitutions properties were also explored. The MFGM proteins, isolated from early-, mid- and late-season fresh whole milks, were characterized using one- and two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under reducing and non-reducing conditions. SDS-PAGE under reducing conditions showed the presence of about 40 protein bands, ranging in molecular weight from 15 to 200 kDa. The major MFGM proteins e.g., xanthan oxidase, butyrophilin, PAS 6 and PAS 7 constituted 60-70% of total MFGM proteins while 20-30% were minor proteins. Two-dimensional SDS-PAGE indicated that xanthine oxidase and butyrophilin might be complexed via intermolecular disulfide bonds in the natural MFGM. The examination of MFGM proteins heated at > 60 °C in the absence of skim milk proteins (caseins and whey proteins) showed that xanthine oxidase and butyrophilin interacted further to form very high molecular weight protein complexes, whereas PAS 6 and PAS 7 were relatively heat stable and did not form complexes. Heat treatment of fresh whole milk in the temperature range 65-95 °C caused incorporation of β-lactoglobulin (β-1g) into the MFGM. Small amounts of α- lactalbumin (α-la) and κ-casein were also observed in the MFGM material of heated milk. The amounts of β-lg and α-la that associated with the MFGM increased with an increase in temperature up to 80 °C, and then remained almost constant. The maximum values for β-lg and α-la association with the MFGM were ~1.0 mg/g fat and ~0.2 mg/g fat, respectively. Association of β-lg and α-la with the MFGM was described by a first-order reaction (65-85 °C for β-lg and 70-80 °C for α-la) in the low temperature range and by a second-order reaction in the high temperature range (85-95 °C for β-lg and 80-95 °C for α-la). Arrhenius plots showed an abrupt change in temperature dependence of the rate constants at 85 °C for β-lg and 80 °C for α-la. Of the major original MFGM proteins, xanthine oxidase and butyrophilin were not affected by the heat treatment of whole milk, whereas PAS 6 and PAS 7 decreased during heating. Interestingly, this behaviour is in contrast to that shown by these proteins in systems containing no skim milk proteins. The changes in fat globule size and MFGM proteins during the manufacture of whole milk powder were determined using light scattering, SDS-PAGE, confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM). Heat treatment of whole milk by direct stream injection (DSI) prior to evaporation caused a decrease in the fat globule size and an increase in the MFGM protein, through the association of caseins and whey proteins with the MFGM material. Evaporation of milk by a multiple-effect falling film evaporator caused a gradual decrease in the fat globule size and an increase in the MFGM protein after each effect. Caseins dominated the total MFGM protein, indicating the adsorption of casein micelles to the newly formed surface of the fat globules during evaporation. When whole milk was preheated (95 °C for 20 s) before evaporation, the amounts of total MFGM protein were higher (~6 mg/m2 compared to ~4 mg/m2 for the non-preheated whole milk) because of association of whey proteins with the native MFGM proteins and casein micelles. The average fat globule size decreased further upon homogenisation of the concentrated milk. The amount of MFGM protein (mg/m2) of concentrated milk also increased after homogenisation, the extent of the increase being dependent upon the temperature and pressure of homogenisation. Furthermore, heat treatment of concentrated milk to 79 °C either before or after homogenisation also increased the amount of MFGM protein. However, at the same homogenisation temperature and pressure, the amounts of whey proteins in the MFGM of the concentrated milk that was heated after homogenisation were higher than the concentrated milk that was heated followed by homogenisation. The amounts of the major native MFGM proteins did not change during homogenisation, indicating that the skim milk proteins did not displace the native MFGM proteins but adsorbed onto the newly formed surface. The fat globule size of homogenized concentrated milk decreased after spray drying, while the amount of MFGM protein (mg/m2) decreased slightly. Some "uncovered fat" was observed on the surface of powder particles. It is possible that the proteins do not adsorb to all newly formed fat surfaces during spray drying. The reconstitution properties of whole milk powders produced using different processing treatments were determined. High homogenization pressure and temperature used before spray drying resulted in poor reconstitution properties of the powder, particularly when the heat treatment was carried out after homogenization. It is suggested that the proteins adsorbed at the fat globule surfaces during homogenisation of the concentrated milk and their subsequent aggregation during heat treatment play a key role in determining the reconstitution properties of whole milk powders.

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

    Inglis, Raelene (2007)

    Doctoral thesis
    University of Otago

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

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  • Dissolved organic matter in New Zealand natural waters

    Gonsior, Michael (2008)

    Doctoral thesis
    University of Otago

    xi, 186 leaves :ill. (some col.), col. maps ; 30 cm. Includes bibliographical references. "1st of April 2008". University of Otago department: Chemistry.

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  • The impacts of harvesting and the sustainability of a New Zealand Littleneck Clam (Austrovenus stutchburyi) fishery in Papanui and Waitati inlets, New Zealand

    Irwin, Craig Robert (2004)

    Doctoral thesis
    University of Otago

    xxiii, 344 leaves :ill. (some col.), maps ; 30 cm. Includes bibliographical references. "June 2004". University of Otago department: Marine Science.

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  • Transforming Folk: Innovation and Tradition in English Folk–Rock Music

    Burns, Robert G. H. (2008)

    Doctoral thesis
    University of Otago

    From a mixed methodology perspective that includes ethnology, musicology and cultural anthropology, I argue that, despite initial detachment from folk revivalism, English folk–rock has moved closer to aspects of tradition and historical status and has embraced a revivalist stance similar to that of the folk revivals that occurred earlier in the twentieth century. Whereas revivalism often rejects manifestations of mass culture and modernity, I also argue that the early combinations of folk music and rock music demonstrated that aspects of preservation and commercialisation have always co–existed within this hybrid musical style. English folk–rock, a former progressive rock music style, has emerged in the post–punk era as a world music style that appeals to a broad spectrum of music fans and this audience does not regard issues such as maintenance of authenticity and tradition as key factors in the preservation process. Rock music has remained a stimulus for further change in folk music and has enabled English folk–rock to become regarded as popular music by a new audience with diverse musical tastes. When folk music was adapted into rock settings, the result represented a particular identity for folk music at that time. In a similar way, as folk music continues to be amalgamated with rock and other popular music styles, or is performed in musical settings representing new cultures and ethnicities now present in the United Kingdom, it becomes updated and relevant to new audiences. From this perspective, I propose that growth in the popularity of British folk music since the early 1970s can be linked to its performance as English folk–rock, to its connections with culture and music industry marketing and promotion techniques, and to its inclusion as a 1990s festival component presented to audiences as part of what is promoted as world music. Popularity of folk music presented at world music festivals has stimulated significant growth in folk music audiences since the mid–1990s and consequently the UK is experiencing a new phase of revivalism – the third folk revival.

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  • Evolving connectionist systems: Characterisation, simplification, formalisation, explanation and optimisation

    Watts, Michael John (2004-09-06)

    Doctoral thesis
    University of Otago

    There are several well-known problems with conventional artificial neural networks (ANN), such as difficulties with selecting the structure of the network, and problems with forgetting previously-learned knowledge after further training. Constructive neural network algorithms attempt to solve these problems, but in turn have problems of their own. The Evolving Connectionist System (ECoS) is a class of open architecture artificial neural networks that are similar in the way in which neurons are added to their structures, and in the way in which their connection weights are modified. The ECoS algorithm is intended to address the problems with constructive neural networks. Several problems with ECoS are identified and discussed in this thesis. These problems are: the lack of comparison of ECoS with constructive neural networks; the excessive complexity of the Evolving Fuzzy Neural Network (EFuNN), which is the seminal ECoS network: the lack of a testable formalisation of ECoS; the dependence on fuzzy logic elements embedded within the network for fuzzy rule extraction; and the lack of methods for optimising ECoS networks. The research in this thesis addresses these problems. The overall theme of the research can be summarised as the characterisation, simplification, formalisation, explanation and optimisation of ECoS. Characterisation in this thesis means the comparison of ECoS with existing constructive ANN. Simplification means reducing the network to a minimalist implementation. Formalisation means the creation of a testable predictive model of ECoS training. Explanation means explaining ECoS networks via the extraction of fuzzy rules. Finally, optimisation means creating ECoS networks that have a minimum number of neurons with maximum accuracy. Each of these themes is approached in ways that build upon, and are complementary to, the basic ECoS network and ECoS training algorithm. The basic ECoS structure and algorithm is left unchanged, and the problems are addressed by extending that structure, rather than altering it as has been done in other work on EcoS. The principal contributions of this thesis are: a qualitative comparison of ECoS to constructive neural network algorithms; a proposed simplified version of EFuNN called SECoS; an experimentally tested formalisation of ECoS: novel algorithms for explicating SECoS via the extraction of fuzzy rules; and several novel algorithms for the optimisation of ECoS networks. The formalisation of ECoS and the proposed algorithms are evaluated on data from a set of standard benchmarking problems. Further experiments are performed with a data set with real-world applications, namely the recognition of isolated New Zealand English phonemes. The analyses of the experimental results show that the proposed algorithms are effective across both the benchmark data sets and the case study data set.

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