14,551 results for Doctoral

  • A Study of Triton X Series Nonionic Surfactant Solutions

    Qiao, Lijun (1996)

    Doctoral thesis
    The University of Auckland Library

    This work contains some fundamental investigations on Triton X series nonionic surfactants from different aspects. Techniques, such as viscometry, densimetry, diffusion measurement, ultra-violet spectrophotometry, differential scanning calorimetry, surface tension measurement and optical microscopy were employed to acquire the information. Some theoretical analyses were given to the results of these measurements. Triton X surfactants show different properties when they dissolve in different solvents. Aggregation can occur in some solvents, depending on the interactions between solvent and solute. The addition of a surfactant to a solvent will give rise to a solute-solvent interaction and change the solute-solute and solvent-solvent interactions as well. From mass transport properties of the surfactant solutions, these interactions were studied and the contributions to them from each species of the solutions were calculated with a transition-state theory model which is usually used for small molecule systems. Under some reasonable assumptions, a new theoretical method was set up and was able to give a reasonable explanation for the experimental results. The surfactants can also associate with some dyes in both polar and apolar media. The ultra-violet spectra of the surfactant-dye solutions show that surfactant-dye complexes might be formed in the polar and apolar media where the surfactants form regular and reversed micelles respectively. The mechanism of the complexation reactions was studied with equilibrium theory and the charge-transfer nature of the association between the surfactant and dye revealed. The surface tension and. cloud point changes due to the addition of polyethylene glycol were determined to discover the interaction between the water-soluble polymer PEG and the surfactants at the air-solution interface and in the bulk solutions respectively. The mass distribution of the two materials between the two phases produced in the segregation (at the cloud point) of the solutions were determined by their ultra-violet adsorption spectra and densities. The analysis of the cloud point changes was given with the new concepts of polysoap and depletion flocculation. The results show that the size of the micelles, the length of the polymer chains, and the structures of the intra - chain micelles can change the mechanisms of polymer-surfactant interaction and influence the properties of the polymer/surfactant solutions. In a certain range of concentrations, the surfactants aqueous solutions can form liquid crystalline structures which can be observed under a cross-polarised microscope and determined by differential scanning calorimetry. The phase diagrams and their variations with additions of the third component, such as xylene, polyethylene glycol and BaCl2 2H2O have been determined. The effects of temperature and each of the additives on the ordered structures were analysed separately in the light of concepts of spontaneous mean curvature and "salting out" effect. Osmotic coefficients of the surfactant aqueous and methanol solutions were determined with a vapour pressure osmometer, and the activity coefficient of the solvent can be calculated with the osmotic coefficients. The change of the activity coefficient with increase of surfactant concentration shows the interactions of the surfactant with the solvent. In aqueous solution, the addition of surfactant frees the solvent molecules, leading to an activity coefficient larger than 1. In methanol solution, the surfactant addition reduces the fugacity of methanol molecules, resulting in an activity coefficient less than 1. Chemical shift changes of protons of the surfactant molecules in the lH NMR spectra show some information about the configuration of the chains, hydration, and phase structure of the solution system when the surfactant concentration changes over the whole concentration range. From 40% w/w the associated water molecules begin to be lost, and the association number ratio of water molecules and the ethylene oxide unit of the surfactant is 4:1. Electric conductance of electrolytes in the surfactant aqueous solutions are reduced by the addition of the surfactants. The reduction is more significant for large size cations, and the longer the EO chain of the surfactant, the larger the reducing effect on conductance.

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  • Glucose Transporters in Diabetic Complications of the Lens

    Merriman-Smith, B. Rachelle (2001)

    Doctoral thesis
    The University of Auckland Library

    Lens transparency is primarily maintained by the anaerobic metabolism of glucose. Glucose is transported from the aqueous humuor to the lens epithelial cells however, it has not yet been established how glucose penetrates to the inner part of the lens. The core of the lens is acidic, approximately pH 6.5, as an effect of the accumulation of lactate, the end-product of glycolysis. This confirms that glucose is drawn deep into the core of the lens. Until recently it was assumed that glucose was transported to the core via a gap junction-mediated route by cell-cell diffusion. However, passive diffusion is limited in capacity and is unlikely to be sufficient for nutrient transport especially for larger lenses. Instead, an active circulation system has been proposed that has the potential to transport glucose deep into the lens via an extracellular route. This would imply that fibre cells may have evolved their own glucose uptake system, yet no direct evidence to this effect has been available. My thesis describes new molecular evidence that both epithelial and fibre cells have evolved their own glucose uptake system. The rat lens expresses the facilitative glucose transporters GLUTI and GLUT3 differentially. GLUTI is predominantly expressed in the epithelium while GLUT3 is predominantly expressed in the fibre cells of the lens. In the normal lens, this makes good physiological sense. GLUTI has a high Km suitable for situations of high glucose concentrations, as is the case for the epithelium where the aqueous humour mirrors glucose concentrations found in blood. GLUT3 has a lower Km and is particularly suitable for the fibre cells, where the supply of glucose from the tortuous extracellular space is limited. The discovery of GLUT3 in the fibre cells lends strong support for the existence of an active circulation system in the lens and makes it seem unlikely that glucose is transported into the core via gap junction-mediated diffusion. In the diabetic state, sorbitol - a product of glucose metabolism, occurs at elevated levels of about 30 times more than that of the normal, suggesting a significant increase in glucose uptake. This imposes an osmotic stress on the lens, which can be countered by regulated cell volume decrease only in the outer but not in the inner cortex. As a consequence inner cortex tissue breaks down and opacities result. My studies of the diabetic rat lens shows that the situation is made worse by an apparent up-regulation of GLUT3 in the fibre cells. Quantitative RT-PCR shows that the GLUT3 transcript is up-regulated six-fold during the initial weeks of diabetic insult in the streptozotocin rat model. The up-regulated GLUT3 protein is detected in the region where maximum tissue damage occurs. These results suggest a new mechanism for the initial tissue damage in the diabetic lens, whereby increased uptake of glucose leads to an over-production of sorbitol which causes osmotic stress on the fibre cells that is beyond their defense capability of regulated cell volume decrease. While my results described above have revolutionized our view of nutrient transport in the lens and its potential role in the early stages of diabetic cataract, the picture is only complete when the functionality of GLUT3 can be demonstrated. For this purpose, vesicles were prepared from isolated lens fibre cells and subjected to quantitative uptake studies using a fluorescent glucose derivative. Uptake was greatly reduced using the GLUT-specific inhibitor phloretin demonstrating that GLUT3 of the rat lens fibre cells is indeed fully functional. In summary, my results add a new dimension to our understanding of how the lens maintains homeostasis and tissue transparency. The lens has evolved an ingenious system to supply, nutrients to the core region to compensate for the absence of a vasculature. However, by achieving this, it has rendered itself unable to defend itself against the adverse effects of high glucose. My results also contribute towards developing new strategies of rational drug design to prevent or delay cataract.

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  • First language attrition in a second language learning environment: the case of Korean-English late bilinguals

    Kim, Sun Hee (2007)

    Doctoral thesis
    The University of Auckland Library

    This thesis explores L1 attrition among young Korean-English late bilinguals. Thirty Korean immigrants to New Zealand, who had arrived at the age of 12-13 years and had spent at least 2 years in New Zealand, participated in the study. Ten monolingual Korean children aged 12 years served as a comparison group for L1 data. Linguistic data in both L1 and L2 were elicited by a standardised picture-naming test and a story-retelling task supplemented by a stimulated recall protocol. Information related to social variables and language use patterns was elicited through a questionnaire and interviews. Skehan (1996; 1998; 2001) proposes three dimensions of linguistic performance— accuracy, fluency, and complexity. The general findings suggest that accuracy and lexical diversity in L1 are most susceptible to attrition and that there is general positive transfer from L1 to L2 skills. While there is no direct negative interaction between L1 and L2 proficiency, analysis reveals that increasing L2 fluency and a decrease in L1 use have possible indirect effects on attrition in L1 accuracy but not in L1 lexical diversity. The data suggest that, while the frequency of return visits to the homeland is an important social variable, language use involving the father and siblings is also an important factor in attrition or maintenance of L1 proficiency of adolescent late bilinguals. Qualitative analysis conducted on five cases corroborates the quantitative findings. Analyses of speech samples reveal that synthetic structures with semantic ambiguity are most susceptible to L1 attrition. The qualitative analysis also highlights the role of L2 socialisation in L1 attrition in adolescent immigrant children who negotiate their language use and identities in an L2-dominant environment and show different patterns of attrition in their L1.

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  • Professional Expertise: A Model for Integration and Change

    Yielder, Jill (2001)

    Doctoral thesis
    The University of Auckland Library

    The nature of professional expertise has been widely debated in the literature. However it has been examined primarily from a dichotomy of perspectives - either from an experiential or a cognitive focus, without the attempt to integrate these, and other aspects of expertise, into an integrated and coherent model. This research is structured in two sections. The first part incorporates a philosophical discussion, which advances an integrated model of professional expertise. The second part uses a case study focused on the field of medical imaging to illustrate and refine the model. Ten professionals identified as experts in the various sub-specialties within medical imaging were guided through a sustained period of interviews and logging of critical incidents in order to elicit in-depth data in relation to the process of expertise. Findings showed that while expertise is situated in the context of practice, it incorporates several dimensions working together in an integrated, seamless fashion through the medium of the individual practitioner. The proposed model integrates five main aspects, namely: knowledge base; cognitive processes; internal integrative processes; interpersonal relationships; and professional practice. That is, it is a synthesis of a particular knowledge base, the cognitive processes, personality and internal processes of the practitioner. It manifests through, and builds on, interpersonal relationships with clients and other professionals, and is expressed through the actual doing of professional practice. It is through the reflexive examination of practice and management of change that professionals may transform these five integrated aspects into the qualitative state of expertise. One of the implications of these findings for higher education are that institutions providing professional education need to value all the dimensions of expertise and their effective integration in order to promote the learning required to advance professionals towards this level of practice.

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  • An investigation of giant Kerr nonlinearity

    Rebic, Stojan (2002)

    Doctoral thesis
    The University of Auckland Library

    This thesis investigates the properties of an atomic system exhibiting a giant Kerr nonlinearity. The atomic energy level scheme involves four energy levels. A three level A subsystem in the atom exhibits the effect of electromagnetically induced transparency (EIT), reducing the spontaneous emission noise. The fourth level leads to an ac-Stark shift of the ground state, which in turn leads to a giant, noiseless Kerr nonlinearity. Two different environments are explored. First, a system comprising of large number of atoms in an optical cavity is analysed. Detailed aspects of noise reduction in this system are investigated. In particular, strong squeezing in the quadrature in phase with the field driving the cavity mode is found, if the effective coupling of light to the atoms is strong. However, the linewidth of the predicted squeezing is found to be very narrow. This is attributed to a very steep linear susceptibility of the atomic medium. Since the widening of the squeezing window is possible only for weaker effective coupling, in turn reducing the squeezing level, a different environment is proposed. This involves a single four level atom, strongly coupled to the cavity mode. In such a strongly coupled system, the most appropriate approach is found to be that formulated in terms of polaritons – composite excitations of the 'atom-cavity molecule'. Adopting the polariton approach, nonclassical correlations in the field leaving the cavity are investigated. Strong photon antibunching is found and the effect of photon blockade predicted and described. The photon blockade effect can also be found in a system comprised of a two level atom coupled to the cavity mode, if the external driving is tuned to one of the vacuum Rabi resonances. A comparison between the two schemes is performed, and it is found that the four level scheme exhibits much better photon blockade. The reason for this is quantum interference between secondary transitions in the dressed states picture. Destructive interference cancels the transitions that would otherwise introduce a second photon into the system, hence producing a more robust photon blockade. All of these results are valid in the regime where external driving is weak. If the external driving strength is increased, the photon statistics (as measured by the zero-delay second order correlation function) changes from strong antibunching to strong bunching, over a relatively narrow range of driving strengths. The occurrence of this change can again be attributed to quantum interference. It is shown that the interference effect prevents the excitation of the composite system by a second photon, but not excitation by a two-photon transition (following the first excitation). Therefore, the third excitation manifold is excited, which then decays back to the first manifold in a two photon cascade. This two photon cascade is the source of correlated photon pairs causing an increase in the second order correlation function. The dynamics of forward scattering of light is presented, and nonclassical behaviour of the delay dependence of correlation function ('overshoots' and 'undershoots') is discussed. For the analytical treatment of this system, a method based on the polariton approach is devised, which includes the treatment of driving and damping. It is shown that this method is ideally suited to the analysis of strongly coupled systems, where only a few photons contribute to the dynamics.

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  • The hydrolysis of amides and ureas in acid solutions

    Giffney, Carolyn Janet (1974)

    Doctoral thesis
    The University of Auckland Library

    Despite the vast amount of research reported on the acid-catalysed hydrolysis of amides, the mechanism of reaction has remained a source of controversy. The various literature results have been summarised in the introduction. Two series of amides have been studied in this investigation, one a series of N-substituted, 4-chlorobenzamides, the other a series of substituted acetanilides. Their basicity (or acid-dissociation) constants have been evaluated in sulphuric acid, and the rates of hydrolysis measured over a wide range of acid concentrations. Within each series, variation of the substituent causes the rate constant to vary in a way which is typical of a bimolecular reaction involving rate-determining nucleophilic attack of water on the protonated intermediate. By drawing a comparison between the two series of amides, (i.e. the difference in basicities and rates of hydrolysis) it becomes apparent that the 0-protonated amide, which is thermodynamically favoured, is not the kinetically active species, A new rate equation is proposed, the equation being based on a mechanism in which water attacks the carbonyl carbon in the rate-determining step. The equation confidently predicts the experimental rate-profiles for the acid-hydrolysis of simple amides. It has been applied, in two forms, to the experimental rate data; the first form allows for the involvement of three water molecules in the slow step of hydrolysis, and the second form allows for the involvement of only two water molecules. The rate equation, in these two forms, has also been applied to much of the hydrolysis data reported in the literature and again it has proved to be very successful. In contrast to the amides, ureas have not been subjected to extensive research. In this investigation, the basicity constants of a series of substituted phenylureas have been measured, (if not already available) and the hydrolysis reactions carried out over a wide range of sulphuric acid concentrations, as well as in water. The 4-methyl and 4-chloro-phenylureas have also been hydrolysed in a range of hydrochloric and perchloric acid solutions; the effects of added salt were studied and the solvent isotope effects on the rate were evaluated. All these results, together with information obtained from application of the Hammett equation to the rate data, were in agreement with a mechanism involving a pre-equilibrium protonation to form the minor, N-protonated conjugate acid. This is followed by a slow transfer of the proton attached to the alternate nitrogen atom to form the appropriately substituted phenylisocyanate, and rapid reaction of this intermediate to form products. The substituent effects on the n.m.r. spectra of the substituted acetanilides and phenylureas have also been reported.

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  • CHESS: Chief Executive Stress Survival: a study of occupational stress in New Zealand top management

    Robinson, Paul F. (1991)

    Doctoral thesis
    The University of Auckland Library

    Whole document restricted, but available by request, use the feedback form to request access. This study develops and used a CHESS (chief Executive Stress Survival) model developed from the occupational stress literature to predict variations in the psychological and physical stress experience and health risk of chief Executives of New Zealand organisations. The model proposes that stress is a sequential process with identifiable phases and that variation are mainly due to the frequency of environmental experiences and stressor factors which are both “chronic” and “episodic”, “at work” and “outside work”. The model also assumes, however, that the impact of the environmental variables and stressor factors are moderated by individual personality differences, coping mechanisms and stress management practices. The model was tested on a sample of 107 male chief Executive officers and General Managers. It was found that the majority of the sample (80%) were relatively stress resistant and healthy. Stepwise multiple regression was used to test the model, and some evidence derived suggests that the frequency of environmental problems does predict various stress symptoms and that environmental stressors ultimately predict health risk profiles. Individual differences are shown as being largely independent variables predicting stress, rather that being moderating variables as suggested by the model. Coping and stress management variables are also shown to play a significant moderating role in the stress - outcome relationship. Some evidence derived suggests that there may be individual manager profiles, provisionally labelled “stress immune” vs “vulnerable” and “ill - health preventers” vs “non-preventers”. Due to the depth of the cross-sectional data obtained on this rarely studied management level, some comparison with published information on other researched groups are explored. A number of limitations of the study are noted. The practical implications for this senior management group of the findings of this study are also examined.

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  • Inhibitory dimensional and inhibitory stimulus control in pigeons with forebrain lesions

    Wild, John Martin (1974)

    Doctoral thesis
    The University of Auckland Library

    Lesions were placed in several areas of the telencephalon and diencephalon of the brain of the pigeon and the effects on the acquisition of inhibitory dimensional and inhibitory stimulus control were observed. The experimental tasks consisted of both visual and auditory interdimensional discriminations each of which had two components: In the first the stimuli were presented successively on the one response key (the main key) according to a multiple variable-interval extinction schedule. In the second the multiple schedule still obtained but a changeover key was added which, when pecked, changed the main-key stimulus, together with its associated schedule of reinforcement, to the next in a randomly ordered series. The use of these two components allowed the separation of two aspects of inhibitory control in learning: response reduction and stimulus reduction thereby permitting the assessment of discriminative ability in the absence of the confounding factor of response reduction. Inhibitory dimensional and inhibitory stimulus control were assessed by post-discrimination generalization tests and combined-cue tests, respectively. It was found that lesions to areas considered limbic - hippocampus, septum, anterior dorsomedial thalamus - had no effect on the learning of a visual discrimination. Lesions to the dorsolateral thalamus produced a complete inability to learn this discrimination, presumably due to disruption of visual fibres en route to the telecephalon. Lesions to the Wulst produced a visual discrimination learning deficit in some birds but not in others, an inconsistency not accounted for by differences in lesion size. Wulst lesions also produced an auditory discrimination learning deficit and in this case the larger the lesion, the larger the deficit. Lesions to ectostriatum produced a deficit in the visual task and lesions to Field L, an auditory projection area, produced a deficit in the auditory task, but not in the visual task. However, in most cases the discrimination learning deficit which was produced was confined to the multiple schedule where the animal had no control over the presentation or duration of the stimuli. Once the changeover key was introduced most birds obtained the learning criterion very quickly by "switching out" of the negative stimulus. This effective changeover responding, together with unimpaired inhibitory dimensional or inhibitory stimulus control, suggested that although the initial learning deficit might be described in terms of an inability to withhold responding in the presence of stimuli previously correlated with reinforcement, this inability could not readily be explained in terms of a lesion-induced impairment in an inhibitory process.

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  • Identification of Hordeum vulgare-H bulbosum recombinants using cytological and molecular methods

    Zhang, Liangtao (2000)

    Doctoral thesis
    The University of Auckland Library

    Barley (Hordeum vulgare L. subsp. vulgare) is an important crop and ranks fourth in overall production of the major cereal crops in the world. Like other cereal crops, barley suffers from a narrowing of its genetic base and susceptibility to diseases, pests and environmental stresses. H. bulbosum is a possible source of desirable genes for introgressing into barley to restore genetic diversity and improve current cultivars. Sexual hybridisation between barley and H. bulbosum is the main method for interspecific gene transfer in barley breeding but there are several barriers to overcome. Two of these are reduced recombination and the ability to identify recombinants quickly and efficiently. The aim in this thesis was to gain a better understanding of meiotic chromosomal behaviour in the two species and their hybrids and to improve the characterisation of recombinants from the hybrids. To study the events during meiosis, synaptonemal complex (SC) analysis was carried out on the two species and two H. vulgare - H. bulbosum hybrids. The results indicated that there were interspecific and intraspecific variations in SC length. Mean SC length was positively correlated with recombination frequency but not related to genome size. This suggests that the ratios of mean SC length to genome size (SC/DNA) show divergence among these Hordeum examples. An hypothesis based on the conformation of chromatin associated with axial element, which is dependent on SC/DNA ratio, was presented to explain the relationship between SC length and recombination frequency. Chromosome pairing in the two hybrids was determined by observation at pachytene and metaphase I (MI). Mean percentages of synapses were similar but there were different frequencies of MI pairing between these two hybrids, indicating that different mechanisms may regulate synapsis and MI pairing in the hybrids. To investigate meiotic recombination, genomic in situ hybridisation (GISH) was performed on the two hybrids at MI and anaphase I (AI). It was observed that intergenomic pairing and recombination events occur in distal chromosome segments. A great discrepancy between mean pairing and recombination frequencies was observed in both hybrids and several possible reasons for this discrepancy were discussed. Hybrid 102C2 with high MI pairing had a significantly higher recombination frequency than the low pairing 103K5, suggesting that high MI pairing appears to be associated with high recombination in the hybrids. An interesting finding is that the ratio of recombination to MI pairing in 103K5 (l:8.9) is twice as high compared with 102C2 (l:17). However, the mechanism for this difference in the ratio between the two hybrids remains unknown. Sequential fluorescence in situ hybridisation (FISH) and GISH were used successfully to localise the introgressions in selfed progeny from a tetraploid hybrid derived from chromosome-doubled 102C2 (102C2/colch). This procedure is fast, cheap and can efficiently detect and locate introgressions. Several disease-resistant recombinants were analysed in more details and leaf rust and powdery mildew resistance was associated with distal introgressions on chromosomes 2HS and 2HL (leaf rust) and 2HS (powdery mildew). It is possible that the leaf rust and powdery mildew resistances were closely linked in the distal region of 2HS. A considerable variation in introgression size was observed at similar chromosomal sites among the different recombinants, which will provide useful information for map-based cloning of genes.

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  • Class and occupational mobility among farm employees

    Loveridge, Alison, 1955- (1991)

    Doctoral thesis
    The University of Auckland Library

    Class mobility in farming works both ways, some farmer's children are unable to afford a farm, while others from non-farm families do succeed in farm ownership. The literature reviewed in this thesis suggests this situation is related to New Zealand's economic history. In the past small family farms have benefited from both secure markets and governments whose interests have been closely bound up with high productivity. This has led the state to offer cheap credit to prospective farmers with little cap1al of their own. Upward mobility has been possible, but at the same time state support has enabled relatively small farms to remain viable, and many of these are unable to secure farm ownership for all family members. In this thesis I explore class mobility and career patterns among farm employees and consider their wider implications. There are many ambiguities in farm employment in New Zealand which stem from the predominance of petty bourgeois farm owners. Such farmers must deal with the capitalist markets of other sectors when they purchase inputs or sell their product but family workers may act as a bulwark against commercial pressures by accepting lower incomes. Similar conditions may be forced on working class farm employees with no chance of ownership. The high number of people leaving farm employment offers indirect confirmation of such problems and this thesis investigates the context in which departures occurred. Farm employees consist of three groups, those without interest in farm ownership, those with an interest and little chance of success, and those whose family background ensures farm ownership. Many farms only have one employee and take on non-family labour for short periods when the family labour which would otherwise do the task is unavailable. Some of the people they employ are offspring of neighbouring farm owners. This variation in class interests has exacerbated the disinclination of farm employees to lake collective action in the face of poor wages and conditions. By tracing a sample of farm employees through the electoral rolls over a period of ten years, I have been able to contact three groups of farm employees: those who have left for non-farm work in the intervening period; those who have been farm workers for at least ten years; and those who have since become farm owners. This has given me an insight into the proportion of farm employees who take up farming hoping to own their own farm, and the problems involved in succeeding. People who have left farming also provide an important perspective on farm employment. I have correlated outcome of career by various background factors, principally father's occupation, aspiration, and education. Job history is also important to my analysis. All these factors influence class mobility, and may either increase or mask the action of each other in different circumstances. By looking at mobility I will demonstrate the way class relationships impinge on individual lives.

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  • Migration and settlement in Indian, Korean and Chinese immigrant communities in Auckland: a perspective from the political ecology of health

    Anderson, Anneka (2008)

    Doctoral thesis
    The University of Auckland Library

    This research used tuberculosis (TB) as a lens to elucidate how migration, settlement, local agency and support networks influence migrants’ health in New Zealand. The study also examined specific characteristics of TB such as delays in diagnosis and the stigma attached to the disease to gain a broader understanding of TB experience for migrants in New Zealand. The research addressed these aims through the analytical framework of political ecology and incorporation of interviews, participant observation and media analysis. Participants in the research included immigrants from Mainland China, South Korea, and India, and New Zealand health care professionals. The study found that immigration policies, social discrimination and isolation have created structural inequalities between dominant host populations and Asian migrants in New Zealand. These inequalities compounded settlement problems such as language difficulties and limited employment opportunities, resulting in low income levels and perceived stress for Indian, Korean and Chinese people, which has affected their health and well being. Transnational policies and experiences of health care systems in immigrants’ countries of origin and in New Zealand strongly influenced health seeking behaviour of migrants, along with structural barriers such as lack of Asian health care professionals and interpreting services. Local cultural and biological factors including health cultures and physical symptoms also affected these practices. In relation to TB, structural processes along with clinic doctor-patient relationships and social stigmas created barriers to diagnosis and treatment. Factors that facilitated access to health care in general, and TB diagnosis and treatment in particular, included the use of support networks, particularly local General Practitioners from countries of origin, and Public Health Nurses, along with flexible TB treatment programmes. This study shows that the incidence and experience of TB is shaped by migration and settlement processes. It also builds upon other medical anthropological studies that have employed political ecology by demonstrating its usefulness in application to developed as well as developing countries. In addition, the study contributes to the growing area of Asian migration research in New Zealand, illustrating that migration and settlement processes are complex and need to be understood as multidimensional, thus demonstrating advantages in approaching them from a political ecological framework.

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  • PulA, a thermostable pullulanase from an extreme thermophile Caldocellum saccharolyticum

    Albertson, Gregory David (1992)

    Doctoral thesis
    The University of Auckland Library

    The pullulanase gene from Caldocellum saccharolyticum, an obligate thermophilic anaerobe, was sequenced and expressed in E. coli. Expression and substrate induction studies in E. coli showed that while gene expression was substrate inducible and the enzyme was exported into the growth medium in C. saccharolyticum, expression was non-inducible in E. coli and the enzyme remained in the cytoplasm. The nucleotide sequence of the pulA gene was shown to be 2478 basepairs (bp) in length, coding for a protein of 96 kDa. The proposed promoter sequences showed homology to both the standard E. coli sequences and the consensus sequences obtained from other C. saccharolyticum genes. The enzyme from the native organism was purified from the growth medium and shown to have a molecular mass of approximately 120 kDa. Periodic acid-Schiffs staining showed that this enzyme was glycosylated and substrate characterisation revealed that the enzyme debranched pullulan to produce only maltotriose, but hydrolysed amylopectin, amylose and β-limit dextran to produce a number of smaller oligosaccharides. The enzyme was expressed in E. coli from its own promoters and was purified from the cytoplasmic fraction. Substrate characterisation revealed that the enzyme debranched pullulan to produce only maltotriose, but had only limited activity on β-limit dextran and amylopectin, and no activity on amylose. The pullulanase gene was also expressed under the control of a heat-inducible overexpression system in E. coli and a copper-inducible expression system in yeast. Amino acid homology comparisons of the pullulanase to other pullulanase sequences and related enzymes revealed a high degree of homology, particularly around three highly conserved regions. In α-amylases amino acids in these regions are involved in catalytic activity, substrate binding and metal ion binding.

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  • Teaching and learning with technology as enabler: a case study on flexible learning for postgraduate nurses

    Honey, Michelle Lorraine Lewis (2007)

    Doctoral thesis
    The University of Auckland Library

    The aim of this study was to explore the practice of flexible learning for postgraduate nurses. Flexible learning is a contemporary approach to learning that utilises the benefits of technology. Flexible learning can be understood as a continuum, from fully on-line or web-based courses, to those that are on-campus and supported by technology. Internationally, the rise of flexible learning has been influenced by increased demand for higher education and competition among providers within the context of reduced education funding. The study population, New Zealand postgraduate nurses are accessing higher education in increasing numbers to advance their practice and to position themselves for new roles and opportunities. These are often experienced nurses yet inexperienced in higher university education, who combine study, work and other commitments. The study employed a qualitative case study design because it enabled multiple perspectives to be gained. Data included documentation, participant observation, survey, students’ assessed work and interviews with key stakeholders: student, teacher and the organisation. Data collection and analysis occurred simultaneously as an iterative process. Thematic analysis was conducted on reviewed documentation, participant observation and interviews. The survey was analysed using descriptive statistical analysis techniques. Finally, a rubric was constructed as a matrix for analysing assessed work. The study identifies the elements that contribute to flexible learning and the interconnectedness between the elements within the dynamic context of a university to illustrate that effective flexible learning can be provided by using a student centred approach to ensure the learning needs of postgraduate nurses are met. Flexible learning was found to improve access, choice, and provide an emphasis on the student as central to learning. In response to these findings the weighting of recommendations are toward the organisation as it is at this level where greater change can be made to improve support for flexible learning provision.

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  • Uttar Pradesh - lagging state of India: economic development and role of banks

    Arora, Rashmi Umesh (2007)

    Doctoral thesis
    The University of Auckland Library

    The present study challenges the negative and static stance of the recent literature on Uttar Pradesh, the most populous state of India, and espouses a balanced and moderate approach. The existing literature focuses only on human development and ignores the underlying social, political and economic changes taking place in the state. It ignores the decline in credit to the state. The present study synthesises and amalgamates various streams of literature on the state to fill the gap. It uses bank credit and its role in UP’s economic development as a tool to explore the changes and structural and regional shifts in the state. It examines bank credit to various regions, districts, occupations, rural and urban populations, large and small borrowers and gender in UP. This study explores credit in a multi-dimensional framework as a route to growth, development, inequality, globalisation, urbanisation, and empowerment. The study further explores the relationship between bank credit and the state’s human development. As a critique of the existing literature, the study examines whether UP is really lagging behind other states of India. Through a twin indicator approach, broadly grouped into income and non-income, the study shows that the state does lag on income front. The non-income indicators analysis, however, shows that a number of other states including high-income states are lagging. The study eschews the watertight categorisation of east and west UP as pursued in the existing literature, and adopts a broader regional classification. This showed that, although gradual, change has occurred in UP. The overall findings of the study suggest that structural and non-structural constraints characterise the development of the state. The multiple roles of credit have generated growth, helped in poverty reduction, but also influenced regional inequality and rural-urban inequalities, and widened the gap between small and large borrowers in the state. The empowerment of women through credit from commercial banks remains a distant goal as women receive less than 20 per cent of the total credit. Another significant finding of the study is that the income and non-income factors are strongly correlated, for instance, the strong negative relationship between income and the Human Poverty Index. The study, therefore, underlines the need for increased economic growth to achieve better economic and human development outcomes.

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  • Factors associated with cognitive ability in middle childhood

    Withdrawn - Theodore, Reremoana Farquharson (2008)

    Doctoral thesis
    The University of Auckland Library

    There has been considerable debate among cognitive psychologists and epidemiologists regarding which determinants of children’s intelligence are most important. Factors such as children’s diet, maternal stress and social support are important for general health and wellbeing, but have received little research attention in longitudinal studies involving cognitive outcomes. Few studies have examined the determinants of intelligence in children born small-for-gestational age (SGA) at term even though these children may be particularly vulnerable to poorer postnatal environments. The aim of this study was to identify factors associated with cognitive ability in middle childhood in New Zealand (NZ) European children and children born SGA. The present research was conducted as part of the Auckland Birthweight Collaborative (ABC) study. Approximately half of the children in this study were born SGA (birthweight10th percentile). Information was collected from mothers and children on pregnancy, obstetric, socio-demographic, postnatal and dietary factors when the children were born (n=871), at one year (n=744), 3.5 years (n=550), and 7 years of age (n=591). Cognitive ability was assessed at 7 years using the Wechsler Intelligence Scale for Children – Third Edition. For the total sample, the analyses utilised weighting to allow for the disproportionate sampling of children born SGA. Results showed that SGA and AGA children did not differ in intelligence at 7 years. Factors associated with intelligence included maternal pregnancy factors (e.g. hypertension), socio-demographic factors (e.g. paternal education), and postnatal factors (e.g. maternal social support). In general, the effects of environmental factors did not differ significantly for SGA children compared with AGA children. A number of dietary factors were also found to be significantly and positively associated with intelligence measures including higher intakes of breads and cereals and weekly fish consumption. In contrast, daily margarine consumption was associated with significantly lower intelligence scores, particularly in SGA children, and this is the first study to report this association. iii Dietary and “environmental” factors were stronger predictors of children’s intelligence in middle childhood than “biological” factors, such as infant’s birthweight. Importantly, most of the factors associated with intelligence that were identified in this study are potentially modifiable. Further research is needed to examine whether these factors continue to be associated with cognitive ability in later childhood.

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  • Feeding the frontiers: logistical limitations of Roman imperialism in the West

    Thomas, Christopher Felstead (2004)

    Doctoral thesis
    The University of Auckland Library

    This thesis is an examination of the importance of army supply in deciding the success and failure of the frontiers of the Roman Empire with particular emphasis on those frontiers in the Rhine-Danube provinces. It will look at logistics as the reason for the end of expansion of the Roman Empire and the frontiers forming where they did. It will also argue that the failure of logistics was a major factor in the collapse of those same frontier defences and the ultimate fall of the western part of the empire. The need to feed and supply large numbers of troops and their dependents dictated where they could be based. Because of the impossibility of supplying the whole army with imported goods, the suitability of local land for food production was also paramount. The need to have reliable sources of supply locally was met by placing veterans on retirement in villae rusticae in frontier zones. This had the effect of controlling those local sources of supply and also satisfying the increasingly expensive needs of the army praemia militiae. The increased warfare and periodic invasions from the reign of Marcus Aurelius especially on the upper Rhine and upper Danube made supply more difficult. The army placed an increasing number of beneficiarii consularis on important points on the transport network to control and direct the flow of army supplies. The more frequent invasions across the frontiers from the third century caused greater dislocation to the agricultural infrastructure not only on the frontiers but deeper into the more settled and richer provinces. This destroyed the sources of local supply and also often the source of imported supply, forcing Roman armies to stay well inside the imperial boundaries more often than before. The loss of their logistic superiority spelt the loss of their military advantage, and the loss of empire.

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  • Discovery of the novel mouFSnrp gene and the characterisation of its in situ expression profile during mouse neurogenesis

    Bradoo, Privahini (2007)

    Doctoral thesis
    The University of Auckland Library

    Recently, a novel protein family, named as neural regeneration peptides (NRPs), was predicted across the rat, human and mouse genomes by one of my supervisors, Dr. Sieg. Synthetic forms of these proteins have been previously shown to act as potent neuronal chemoattractants and have a major role in neural regeneration. In light of these properties, these peptides are key candidates for drug development against an array of neurodegenerative disorders. The aim of this PhD project was to provide confirmation of the existence of a member of the NRP coding gene family, annotated in the mouse genome. This gene, called mouse frameshift nrp (mouFSnrp), was hypothesised exist as a -1bp frameshift to another predicted gene AlkB. This project involved the identification of the mouFSnrp gene, and the characterisation of its expression pattern and ontogeny during mouse neural development. Through the work described in this thesis, the mouFSnrp gene was identified in mouse embryonic cortical cultures and its protein coding gene sequence was verified. mouFSnrp expression was shown to be present in neural as well as non-neural tissues, via RT-PCR. Using non-radioactive in situ hybridisation and immunohistochemical colocalisation studies, interesting insights into the lineage and ontogeny of mouFSnrp expression during brain development were revealed. These results indicate that mouFSnrp expression originates in neural stem cells of the developing cortex, and appears to be preferentially continued via the radial glial lineage. mouFSnrp expression is carried forward via the neurogenic radial glia into their daughter neuronal progeny as well as postnatal astrocyte. In the postnatal brain, mouFSnrp gene transcripts were also observed in the olfactory bulb and the hippocampus, both of which are known to have high neurogenic potential. In general, the radial glial related nature of mouFSnrp expression appears to be a hallmark of the mouFSnrp expression pattern through out neural development. This thesis provides the first confirmation of the existence of a completely novel gene, mouFSnrp, and its putative -1 translational frameshifting structure. Further, preliminary data presented in this thesis regarding the mouFSnrp in situ expression pattern during mouse brain development may suggest a key role of the gene in neuronal migration and neurogenesis in mice.

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  • Biological studies on turnip yellow mosaic virus in Brassica pekinensis

    Fraser, Lena (1982)

    Doctoral thesis
    The University of Auckland Library

    Whole document restricted due to copyright restrictions but available by request use the feedback form to request access 1. When purified turnip ye1low mosaic virus was inoculated mechanically on to Chinese cabbage leaves, using known numbers of virus particles in 0.1 to 1.0 µ1 volumes of inoculum, as few as 10 to 30 particles were required to produce a single local lesion.2. Inoculation of a cotyledon leaf of Chinese cabbage seedlings with turnip yellow mosaic virus produced a rapid transient inhibition in the rate of leaf initiation, so that infected plants developed 0.5 to 1.0 leaf less than healthy plants. 3. The factor that initiated the inhibitory response a t the apical. meristem began moving out of the inoculated cotyledon within 1to 6 hours after inoculation, thus preceding the movement out of the inoculated cotyledon of infectious virus or RNA which was not detectable until about day 5. 4. The transient inhibition of leaf initiation occurred following inoculation with any one of three unrelated viruses, or with infectious turnip ye1low mosaic virus RNA. 5. A factor eluted in an active form from the cut petioles of inoculated 1eaves. 6. It is necessary to inoculate with infectious virus or RNA to initiate the production of the inhibitory factor. 7. No differences were seen in the magnitude or timing of the reduced rate of 1eaf initiation, when the concentration of turnip yellow mosaic virus in the inoculum was varied between 1 µ g/ml and 100 µg/ml. 8. Inoculation of the cotyledons of Chinese cabbage seed1ings with turnip ye1low mosaic virus caused a marked disturbance in the mitotic index a t the apical meristem between 6 and 48 hours. 9. A reduction in the accumulation of starch in the chloroplasts of cell s in the apical meristem occurred at 6 t o 24 hours after inoculation of the cotyledon 1eaf. 10. Abscisic acid applied to the cotyledon in a single 20 µ1 dose, elicited a response that closely paralleled the events that took place when Chinese cabbage seedlings were inoculated with turnip yellow mosaic virus. A decrease in the rate of leaf initiation began 1 t o 2 days after application and the inhibition of leaf initiation was preceded by a disturbance in the mitotic index in the apical meristem. 11. Gibberellic acid applied with the eluate from virus-inoculated leaves, was able to overcome the inhibition of leaf initiation. 12. The leaf inhibition assay in Chinese cabbage seedlings is a sensitive bioassay for abscisic acid. The minimum detectable concentration of 3 x M is comparable to those reported for the Commelina stomata1 closure bioassay which could detect 10 -10 abscisic acid (Ogunkanmi et a1 . 1973).

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  • Characterization of calpain 3 transcripts in mammalian cells : expression of alternatively-spliced variants in non-muscle cell types

    Dickson, James Michael Jeremy (2008)

    Doctoral thesis
    The University of Auckland Library

    An investigation of the expression profile of mRNA encoding Calpain 3, the causative agent in the inherited human muscular disease Limb Girdle Muscular Dystrophy Type 2A, was conducted in two representative mammalian species, human and mouse. Transcripts encoding Calpain 3 were identified from mammalian tissues other than skeletal muscle. In human Peripheral Blood Mononuclear Cells (PBMCs) these transcripts were identified in both the T-cell and B-cell compartments and in a number of human blood cell lines representing different haematopoietic lineages. Calpain 3 transcripts encoding the murine homologue were also described from mouse PBMCs and from murine tissues involved in haematopoiesis. In addition to the confirmation of Calpain 3 expression in non-skeletal muscle tissues in both these species, transcripts were identified with precise and defined deletions, which mapped to known exon-exon boundaries in the Calpain 3 gene from both species. These deletions constituted the removal by alternative splicing of skeletal muscle-specific components of the Calpain 3 protein known to regulate its function in this tissue. Monoclonal antibodies to the Calpain 3 protein were used to confirm the presence of Calpain 3 protein in non-skeletal muscle tissues of both human and mouse. In humans the expression of Calpain 3 protein was confirmed in PBMCs and in the mouse, Calpain 3 expression was confirmed in tissues of the haematopoietic compartment. In both species the Calpain 3 protein expressed correlated with translation from a transcript lacking the skeletal muscle-specific components generated by alternative splicing. An attempt was made using a Yeast Two Hybrid assay to identify potential regulatory molecules of Calpain 3 in human PBMCs, but without a definitive candidate molecule being found. A developmental model of muscle differentiation (murine C2C12 myoblast cells) was used to ascertain the expression profile of Calpain 3 in the early stages of myofibrillogenesis. Using Quantitative Real Time PCR the expression profile of Calpain 3 was assessed in differentiating C2C12 cells. These results showed that the absolute levels of Calpain 3 transcription were elevated during differentiation and that a temporal Calpain 3 isoform shift occurred during this process. This temporal shift in expression was from transcripts having identical deletions to those seen in the haematopoietic tissues, to full length transcripts representative of skeletal muscle-specific Calpain 3. The identification of Calpain 3 expression outside skeletal muscle tissue is novel and the isoforms expressed in these tissues are structurally more analogous to the ubiquitously expressed calpains. This has implications for LGMD2A where a loss of function of Calpain 3 in non-skeletal muscle tissue could be compensated for by the ubiquitous calpains, thus explaining the lack of any non-muscle tissue pathology in LGMD2A patients.

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  • Analysis of trends and reasons for rising acute medical admissions in Auckland's public hospitals

    Benipal, Jagpal Singh (2008)

    Doctoral thesis
    The University of Auckland Library

    The main purpose of this study was to examine empirically the trends and reasons for rising acute adult medical admissions at two major public hospitals in Auckland from 1997 to 2004. According to recent national and international literature published on the topic, there has been unsustainable growth in the adult medical admissions both in NZ and most of the other developed countries. Overall, the causes of this increase have not been explored sufficiently in the literature reviewed. The NZ research has largely focused on the macro-analysis of hospital throughput data from health policy points of view. Methodology: A mixed methodology research design was applied to address the problem. Phase 1 quantitatively analysed adult medical hospital admission data (N = 277,416) obtained from the two hospitals (Middlemore and Auckland Public Hospitals), and phase 2 qualitatively explored the responses and views of the health professional expert panel (n = 16) in relation to the findings of phase 1 of the study. Findings: Overall, the crude number of admissions and age-standardised admission rates at both hospitals increased more rapidly than actual population increases. Approximately 1/3 of the patients accounted for 2/3 of the total admissions. Five major diagnostic categories accounted for 70%-80% of total acute admissions, with circulatory and respiratory system disorders being the leading causes of medical admissions. There was a strong relationship between age and increased admissions. MMH hospital overall, and its ethnic groups separately, had significantly higher admission rates than APH. Comparison of ethnic groups highlighted significant variations in the admission rates at the two hospitals despite adjusting for age, morbidity and deprivation. Conclusions: Overall the increase and variation in admission rates between the hospitals and ethnic groups was dependent on factors such as the characteristics of the population and patients, hospital admission and administration processes, availability of hospital beds, medical management at the hospital, and availability of primary and community care services. By making changes to those factors in the control of hospitals and District Health Boards, hospitals can potentially influence the trajectory of rising medical admissions. These factors include systems for managing patients with chronic illness, and pathways from community services to hospital. Finally, a number of future research areas, such as a large-scale study to explore the health service utilisation of the 55+ age groups, have been proposed.

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