23,243 results for Thesis

  • The Binding capacity of albumin and renal disease

    Dromgoole, Sydney Herbert (1973)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. The capacity of albumin to bind the anionic dye, methyl orange, was determined in normal volunteers, in patients with renal failure and in patients after kidney transplantation in an attempt to elucidate the cause of the observed decreased albumin binding capacity for various drug and dye molecules in these patients. Binding studies were determined at 25°C, in a physiological bicarbonate carbon dioxide buffer system, ionic strength 0.15, using ultrafiltration and gel filtration techniques. Patients with renal failure bad lower albumin binding capacities than the normal volunteers and this reduction was generally unrelated to the degree of renal failure. The order of binding capacity being: patients with acute and chronic renal failure > patients before haemodialysis > patients after kidney transplantation > patients after haemodialysis. This reduction in binding was reflected in the downward displacement of the binding curves of pooled sera of each of the above groups of patients compared to that of normal volunteers. Each binding curve was analysed in terms of three classes of binding sites, and the reduced binding appeared to be due to an alteration in the n and K binding parameters of the intermediate class of sites. The reduced binding after dialysis was shown to be caused by competition by the temporarily increased concentration of non-esterified fatty acids as a result of lipoprotein-lipase activation by heparin administered during haemodialysis. The cause of the decreased binding of the other sera was not apparent, but could have been due to drug or metabolic product competition for the dye binding sites or due to a conformational change in the albumin molecule. The significance of this decreased binding capacity in relation to drug therapy in these patients is discussed.

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  • Dynamic expression patterns of major lens membrane proteins

    Grey, Angus Cheverton (2006)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. Differentiation-dependent expression of membrane proteins is emerging as a common theme in a variety of protein expression studies conducted in the lens. Often however, the physiological relevance of, and cellular signalling mechanisms responsible for these expression patterns is not well understood. The lens microcirculation system, proposed to maintain lens homeostasis, is generated by spatial differences in lens membrane transport and structural proteins. To investigate the roles of major membrane transport and structural proteins in lens homeostasis, high resolution microscopy of lens tissue over large distances is required. This thesis presents the expression patterns of the two most abundant lens membrane proteins, Aquaporin-0 and MP20, which were both shown to change with lens fibre cell differentiation. While changes in the expression pattern of both membrane proteins has been shown previously, the application of a new lens sectioning and imaging protocol has enabled, for the first time, the changing expression patterns of both proteins to be placed in the context of the intrinsic differentiation and age gradient in the lens. Additionally, correlations between protein expression pattern and lens function have been made through immunolabelling of lens sections containing extracellular space markers. Finally, novel techniques have been developed to investigate the post-translational modifications responsible for the changing expression patterns. MP20 was initially found in a cytoplasmic pool which inserted into the lens fibre cell membrane upon degradation of cell nuclei. This membrane insertion event correlated to the formation of a barrier to extracellular diffusion. To investigate the cellular signals involved in MP20 membrane insertion, a biochemical protocol was developed to isolate a pool of MP20 derived from cytoplasmic vesicles, which was compared to membrane-bound MP20 using mass spectrometry. While MP20 was detected in both samples, differential post-translational modifications indicative of a membrane insertion signal were not observed. Initially localised to peripheral lens fibre cell membranes, Aquaporin-0 was found to aggregate predominantly on the broad sides of fibre cells, often in dome-like structures deeper into the lens. As cell nuclei degraded, the signal from an Aquaporin-0 C-terminal antibody was lost briefly, before returning in non-nucleated cells to be strong and membranous. In the lens core, signal was lost, which was shown by Western blotting and mass spectrometry to be due to cleavage of the Aquaporin-0 C-terminus. Conventional dissection techniques were unable to separate the fine zones of Aquaporin-0 labelling, necessitating the development of a novel laser microdissection/mass spectrometry approach to correlate Aquaporin-0 labelling to post-translational modifications. Additionally, MALDI tissue profiling has also been developed to investigate regional differences in the post-translational modification state of Aquaporin-0. Results from these experiments confirmed that loss of Aquaporin-0 C-terminal labelling was due to cleavage. These exciting techniques will be useful tools in the continuing investigation of changes in post-translational modifications of major lens membrane proteins. Knowledge of the high resolution expression patterns of the two most abundant lens membrane proteins has enhanced our understanding of their roles in lens homeostasis. The development of tools to investigate the cellular signals involved in the generation of lens membrane protein expression patterns is crucial if we are to advance our understanding of lens development and function.

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  • Calf Pregastric Lipase-A Kinetic Study

    Manuel, Robyn Desma (1999)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. A commercially available pregastric lipase extract from calf has been partially purified by dialysis, anion-exchange chromatography and gel filtration. The protein fraction of interest, that with the greatest activity against tributyrylglycerol (TBG) was prepared as an emulsion with L-α-lecithin and casein and eluted off an anion-exchange column, after binding strongly to the column at lowered pH and subsequent removal with a high concentration of NaCl (l M). The enzyme thus obtained was named calf pregastric lipase (CPGL) and showed preferential activity against TBG (a short-chain homoacid triacylglycerol), with respect to high values of Vs in combination with diminished KM, in contrast to the values obtained with the water miscible ester, 4-nitrophenyl acetate (4-NPA). Values of VS, the limiting rate of hydrolysis at the lipid / water interface, for the CPGL catalysed hydrolysis of TBG and V, the limiting rate of hydrolysis in a homogeneous solution, for the CPGL catalysed hydrolysis of 4-NPA at pH 6.0 and 35 oc were 8.36 ± 0.44 U mg-1 and 3.60 ± 0.16 U mg-1, respectively. The respective values of KM under the same conditions of pH and temperature were 0.10 ± 0.02 mM for TBG as substrate, and 0.53 ± 0.09 mM for 4-NPA. Sodium dodecyl sulfate polyacrylamide electrophoresis (SDS-PAGE) of the partially purified CPGL indicated the presence of three proteins with molecular weights (MW) corresponding to 44, 62 and 66 kDa. Comparison with literature MW values of pregastric lipases from other well-studied species (human, lamb, kid, goat and rat) identified the protein of interest at 44 KDa. This band was excised and subjected to five Edman degradation cycles. Although the MW of the partially purified CPGL is somewhat lower than the reported MWs of other ruminant PGLs, the resultant N-terminal sequence was in complete agreement with those previously reported for kid, goat, lamb and calf pregastric lipases (F, L, G, K, I). The lower MW lipase isolated in this study may have been partially deglycosylated or undergone uncontrolled proteolysis during the purification procedure. The activity of partially purified CPGL against the short-chain homoacid triacylglycerol, TBG, was further studied over a range of pH values (5.5 to 7.5) and temperature conditions (30 ºC to 50 ºC) and, in the presence of possible inhibitors. The maximum rate of TBG hydrolysis catalysed by CPGL was at pH 6.5 and 40 ºC, and under these conditions the value of Vs, the limiting rate at the interface, was equal to 14.3 ± 0.7 U mg-1. The stoichiometry of the CPGL catalysed hydrolysis of TBG was determined as 'one to one', and CPGL was observed at this early stage of investigations to exhibit substrate specificity for TBG compared with the initial product of hydrolysis, 1,2-(2,3)-dibutyrylglycerol (DBG). The approximate rate ratio for the catalysed hydrolysis of TBG:DBG by CPGL was 30:1. Thermal inactivation of CPGL was evident at high temperatures and especially so in combination with high pH. The enzyme showed a degree of thermal resistance at the lower pH scale and also in the presence of the following proteins: bovine serum albumin, more casein, lactoglobulin and transferrin. The greatest stabilising effect was exerted by the milk proteins lactoglobulin and casein. CPGL was found to be relatively resistant to the gastric protease, pepsin, retaining approximately 70% activity in the presence of 2% w/v pepsin for 1 hour. Proteins added to the TBG emulsion decreased the observed activity of CPGL by either aligning at the lipid / water interface or acting as fatty acid receptors, or both. Short-chain fatty acids (4:0, 6:0 and 8:0), as opposed to the longer chain (10:0 and l2:0) fatty acids, in the TBG emulsion, seriously inhibited CPGL activity, suggesting that the hydrolysis of TBG is more dominant in the aqueous phase than at the interface. The hydrolysis of 4-nitrophenyl acetate catalysed by CPGL was also examined over a range of pH values (6.0 to 8.0) and temperature (30 ºC and 50 ºC) values. Preliminary studies of the reaction milieu established that addition of up to 1.6% v/v acetonitrile, the solvent for the substrate, had very little effect on the measured pseudo first-order rate constant of hydrolysis. Michaelis-Menten parameters were determined in the presence of increasing concentrations of acetonitrile (0.66 - 6.6% v/v). As the concentration of acetonitrile increased, the limiting rate, V, decreased and the value of KM was unchanged. Hence the solvent behaved as a non-competitive inhibitor. Values of initial rate and Kψ were found to be buffer dependent, with relatively greater values being reported in bis tris buffer. Thus all studies were confined to the useful pH range of only one buffer, the choice of which was determined by the pH range under investigation. The maximum limiting rate, V, for the CPGL catalysed hydrolysis of 4-NPA occurred at pH ≤ 6.0 and across a broad temperature range of 35 ºC - 50 ºC. The onset of thermal inactivation of CPGL appeared under noticeably milder conditions than with TBG as substrate, due to less favourable binding of 4-NPA to CPGL. A pK2 value of 5.7 for the CPGL-4-NPA complex was obtained by fitting pH and Kψ data to the Dixon equation. Arrhenius plots of log Kψ against I/T for the CPGL catalysed hydrolysis of 4-NPA was linear up to 42 ºC allowing for calculation of the following thermodynamic parameters: Ea = 37 ± 2 kJ mol-1; A = 4600 ± 200 s-l; ∆H* = 35 ± 2 kJ mol-1; and ∆S* = -O.17 ± 0.02 kJ K-l mol-1. Studies of increasing acyl chain length of 4-nitrophenyl esters and homoacid triacylglycerols showed that CPGL preferentially hydrolyses 4-nitrophenyl decanoate and TBG, respectively. Gas chromatography was used to analyse the hydrolytic products of bovine milkfat catalysed by CPGL. CPGL preferentially hydrolyses the short-chain fatty acids (C4:0 and C6:0) which are dominant at the sn-3 position of bovine milk. Thus, CPGL is both typoselective for short-chain fatty acids and stereoselective for the sn-3 position. A study of the activity of CPGL in the presence of conjugated bile salts and egg phosphatidylcholine (PC) liposomes was undertaken to elucidate the viability of CPGL activity in the duodenum. All the conjugated bile salts studied, whether in the presence or absence of L-α-lecithin, diminished the initial rate of CPGL catalysed hydrolysis of the medium-chain ester, 4-nitrophenyl decanoate. With respect to the conjugated bile salt, the nature of the headgroup and the number and position of the hydroxyl substituents on the steroidal nucleus affect the degree of inhibition. The results indicated that CPGL is unlikely to contribute much, if at all, to fat digestion beyond the stomach (abomasum). Intercalation of 4-NPDe into egg PC liposomes and egg PC:cholesterol liposomes decreases the limiting rate of CPGL catalysed hydrolysis by effectively removing the substrate from CPGL. Phenyl boronic acid (BBA) and diethyl 4-nitrophenyl phosphate (E600) are known inhibitors of serine hydrolases. Both of these inhibited CPGL catalysed hydrolysis of 4-NPA. BBA inhibited CPGL activity in a competitive way and a plot of KM against BBA concentration gave a value of 1.9 mM for the competitive enzyme-inhibitor constant, Ki. This value is similar to that of KM in the absence of BBA and implies that BBA and 4-NPA have a similar affinity for CPGL. In the presence of E600, an irreversible serine specific inhibitor, the activity of CPGL decreased to l8% of the activity in the absence of E600, after 2-hours incubation. This suggests that an essential serine resides at the active site of CPGL.

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  • Sulfur Compounds in the Environment

    Li, Kwong Chi (2003)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. A new analysis method for sulfur compounds using solid phase microextraction (SPME), gas chromatography (GC) and pulse flame photometric detector (PFPD) has been developed in this study. In the method, air samples were collected with Tedlar air sampling bags, Carboxen-Polydimethylsiloxane (Carboxen-PDMS) coated fibers were then used to extract analytes from the samples and introduce them into the injector of a GC by thermal desorption. The analytes were separated using a GS-GasPro column and detected with the PFPD. Using a SPME-GC-PFPD method the retention times of 28 sulfur compound standards were determined for the identification of sulfur compounds in air samples. A method was also developed for the quantification of H2S. The reproducibility (<14%),lowest quantitation limit (4 ppb for H2S) and detection limit (0.4 ppb for H2S) were determined for this method. Emissions from geothermal sources, wetlands and wastewater treatment works are the sources of atmospheric sulfur compounds. Rotorua (New Zealand),a beach near Point England (Auckland, New Zealand) and a wastewater treatment plant were selected for sampling. With the SPME-GC-PFPD method COS, H2S, CS2, SO2, (CH3)2S were identified in the air in residential areas in Rotorua. COS, H2S, CS2, SO2, CH3SH, (CH3)2S and CH3(CH2)2CH2SH were identified in the air around geothermal sources in Rotorua, three additional compounds, C2H5SH, CH3CH2CH2SH and CH3CH2SCH3 were identified in a fumarole emission. It was observed that the H2S concentrations in residential areas were well below the air quality standard for geothermal areas (0.05 ppm) at the time of collection, but the H2S concentrations in the vicinity of geothermal areas were above the standard. COS, H2S, CS2, CH3SH, (CH3)2S, (CH3)2S2, and SO2 were identified in the air in a wastewater treatment plant. As low concentrations of sulfur compounds were detected in the open air they did not cause any odour problems to the workers or the public. It was observed that the H2S concentrations in the open air were below the air quality standard (0.005 ppm) for non-geothermal areas. PM10 samples collected from Hunua, Hamilton and Christchurch in New Zealand, were analysed using a modified SPME-GC-PFPD method. H2S, SO2, CH3SH, (CH3)2S, (CH3)2S2, thiophene and ethyl methyl sulfide were identified in the particulate samples. The concentration of each sulfur compound identified in the samples varied between the three locations, which might have been caused by different emission sources. The newly developed SPME-GC-PFPD trace level analysis method for sulfur compounds and H2S is fast, easily operated, cost effective and reliable. In this study, the applications of this method have been used to demonstrate its versatility for the analysis of sulfur containing samples in various matrices.

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  • Reading readings: some current critical debates about New Zealand literature and culture

    Paul, Mary (1995)

    Doctoral thesis
    The University of Auckland Library

    Whole document restricted. Thesis is now published as a book. Paul M. (1999) Her Side of the Story: readings of Mander, Mansfield and Hyde. Dunedin: Otago University Press. http://www.otago.ac.nz/press/ for more information. This thesis examines contemporary interpretations of a selection of important texts written by New Zealand women between 1910 and 1940, and also a film and film script written more recently (which are considered as re-readings of a novel by Mander). The thesis argues that, though reading or meaning-making is always an activity of construction there will, at any given moment, always be reasons for preferring one way of reading over another-a reading most appropriate to a situation or circumstances. This study is motivated by a desire to understand how literary criticism has changed in recent years, particularly under the influence of feminism, and how a reader today can make a choice among competing methods of interpretation. Comparisons are drawn between various possible readings of the texts in order to classify methods of reading, particularly nationalist and feminist reading strategies. The over-all tendency of the argument is to propose a more self-critical and self-conscious approach to reading, and to develop a materialist and historical approach which I see as particularly important to the New Zealand context in the 1990s.

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  • A privileged moment: 'dialogue' in the language of the Second Vatican Council 1962-65

    Nolan, Ann Michele, 1946- (2003)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. The style of language at Vatican II made a break with the then-current scholastic language of Catholic theology. Less concerned to define, in scholastic mode, the language of Vatican II was more concerned to persuade, in a rhetorical mode that was identified as 'pastoral' at the time. This book takes the central word 'dialogue' as the important interface between these two modes of language, because 'dialogue' had a history in scholastic theology as the finding-the-end-result dialectic of Thomism, yet 'dialogue' in twentieth-century philosophical thought had acquired the Buberian sense of an ongoing relationship that did not lend itself to once-and-for-all definitions. Some of the difficulties that have arisen in implementing the teaching of Vatican II are shown to result from these two different understandings of dialogue, compounded for English-speaking readers by the fact that two different Latin words in the original documents were commonly translated as 'dialogue' in the five major English translations.

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  • More than wives?: a study of four Church Missionary Society wives in nineteenth century New Zealand

    Ross, Catherine R. (2003)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. This is a study of four Church Missionary Society (CMS) wives in New Zealand in the nineteenth century. The women are Charlotte Brown (nde Arnett), Anne Wilson (nee Hawker), Elizabeth Colenso (n6e Fairburn) and Catherine Hadfield (nde Williams). My thesis is that these women who were regarded by the CMS as adjuncts to their husbands were in fact "more than wives." Until recently women, especially wiveso have been virtually invisible in the history of mission. If we train a camera lens back through history we find that the women have been shadowy figures, blurred at the edges so this thesis is an attempt to refocus the camera and to train the lens on these women It brings their lives and experiences into focus and asks certain questions of and about them. A narrative approach is used in collating the lives and stories of these four women. The work begins by surveying the range of literature available on Protestant women in mission in the nineteenth century. This introductory chapter also examines and discusses Dana Robertos framework of the model Christian home as a conscious and intentional paradigm for mission. The next chapter considers and reflects on the British evangelical context which shaped the background and worldview of these women. The chapters on each of the women bring their lives into focus and out of invisibility by asking new analytical questions. These chapters examine whether these women had their own vocation for missionary service and whether they could fulfil this as a missionary wife. They look at how these women understood their role and calling and what kind of work they were involved in and consider to what extent each woman served as an active missionary in her own right and not just as an adjunct to her husband. These chapters also reflect on what we learn from their daily lives and routines that provides a more holistic understandlng of missionary life and service during this period. The thesis concludes by considering how far the model Christian home was a rationale for mission service for these four women and to what extent they were "more than wives."

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  • Daz sint noch ungelogeniu wort: a literary and linguistic commentary on the Gurnemanz episode in Book iii of Wolfram’s Parzival (161,9-179,12)

    Gilmour, Simon Julian (1997)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. The present work is a detailed study of the Gurnemanz Episode in Wolfram von Eschenbach’s Parzival. Its main body encompasses a commentary on the Gurnemanz episode of Wolfram’s work. The intention of the commentary is o provide exact and comprehensive information and discussion on aspects of the text that could cause the reader difficulty, or to enhance his/ her appreciation of the text and the context in which it had its genesis. The commentary follows the principle of analysing from large to small. The largest section encompasses a chapter of the thesis, the smallest an individual word. Each of the five chapters is introduced by a literary interpretation which encompasses, among other aspects such as themes, motifs, plot and character development, structure, and a comparison between Wolfram’s text and that of his source, Chrétien de Troyes’s Perceval. Then a closer examination of smaller units of the text takes place. This includes principally the analysis of Wolfram's use of language and his style. The commentary is introduced by a discussion of the commentary form and the theoretical basis which this work follows, and concluded by a short evaluation. All important secondary literature which appeared before 1997 and was available to the author has been considered for this work. Furthermore, this thesis is appended with an article in German that deals with the possibility of reading Parzival 652,10 and 173,3 with the less favoured MS G readings. This article bears the fruit of the discussion needed to comment on the MS G reading at 173,3, and is soon to be published in the periodical Euphorion. A fold-out copy of the Parzival text for each chapter is found inside the back cover.

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  • Status epilepticus: mechanisms of generation and associated neuropathology

    Young, Deborah (1996)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. Status epilepticus (SE) is a prolonged and dangerous epileptic condition that can cause brain damage and may be one of the predisposing factors for the subsequent development of temporal lobe epilepsy. In this thesis, I investigate causes of SE as well as the receptors maintaining seizures and the associated neuropathological changes (cell death, sprouting) that occur in SE brain. An unequivocal role for a defect in either excitatory and inhibitory systems in SE generation has not been established. An alternative approach to unravelling the causes of SE may be to investigate whether an impairment of endogenous seizure termination mechanisms, likely to be mediated by adenosine may lead to SE development. The findings that specific A1-adenosine receptor antagonists with a central site of action were able to transform brief electrically-induced seizures into SE, while co-administration of specific A1-adenosine receptor agonists blocked this effect supports this hypothesis. Pertussis toxin-treated animals also developed SE after elicitation of a seizure suggesting inactivation of Gi-protein linked receptors are involved in SE development. Although GABAB and 5HT1A receptors are also coupled to the same subset of anticonvulsant K+ channels as the A1-adenosine receptor, antagonists at these receptors could not transform brief seizures into SE following seizure elicitation, although a GABAB, agonist had anticonvulsant effects. While chemically-induced SE models suggest that glutamatergic and cholinergic mechanisms are involved in SE initiation and maintenance, whether similar receptor mechanisms operate to initiate and maintain electrically-induced SE are unclear. Using specific antagonists of muscarinic and glutamate receptors, I have shown that NMDA receptors and possibly AMPA/kainate receptors are involved in the initiation of electrically-induced SE. AMPA/kainate receptors may be predominantly involved in maintaining SE, although NMDA receptors may sustain seizures in neocortical regions. Muscarinic and metabotropic glutamate receptors do not appear to have a role in initiation and maintenance of electrically-induced SE. Distinct neuropathological features associated with SE including cell loss and morphological changes in the hippocampus were observed. As early as six days after SE, selective damage to hippocampal neurons in the hilus, CA1 and CA3 pyramidal regions and interneurons immunoreactive for parvalbumin and somatostatin were observed after SE in the absence and presence of the A1-adenosine receptor antagonist 8-cyclopentyl-l, 3-dimethylxanthine (8-CPT). Seizure severity generated in the presence of 8-CPT is likely to account for the increased neuronal damage found in this model. Other changes included increases in selected GABAA receptor subunit (α1, α2, β2/β3 and γ2) immunoreactivity in the dentate granule cell and molecular layer of the hippocampus suggesting the possible increased formation of GABAA receptors with the subunit configurations α1,β2,γ2 and α1,β3,γ2. Neuronal injury was also accompanied by reactive gliosis and microglial proliferation and astrocytic expression of the growth factors basic fibroblast growth factor (bFGF) and insulin-like growth factor 1 (IGF-1). Long-term sequelae of SE-induced hippocampal damage such as the appearance of spontaneous seizures in the animals and synaptic reorganisation in the supragranular layer of the dentate gyrus were found 1-2 months after SE. The sprouting response was associated with an increase in brain-derived neurotrophic factor (BDNF) immunoreactivity in dentate granule cells and mossy fibre axons 1 and 2 months after SE. A BDNF and clusterin-immunoreactive band was also present in the supragranular layer at 2 months, suggesting these molecules may be involved in mediating the sprouting response. BDNF immunoreactivity was also present in mossy fibre axons in normal and epileptic human hippocampi but was only present in the inner molecular layer in epileptic tissue. In conclusion, the results in this thesis provide some new insights into possible mechanisms of SE development and associated neuropathological changes, which may be applicable to that found in humans.

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  • Computer modelling of reinjection in geothermal fields

    Kaya, Eylem (2010)

    Doctoral thesis
    The University of Auckland Library

    This thesis describes a computer modelling study of reinjection into geothermal systems. The aim of this work was to decide on optimum reinjection strategies for various types of geothermal systems. First an idealized 3D closed model used by Sigurdsson et al. (1995) is extended to examine the effect of the natural recharge from groundwater, from the basement and laterally from the boundaries of the system. The results show that injection increases steam flow if recharge is small because the reservoir is acting as a closed system, or if the caprock is permeable and allows groundwater recharge. Otherwise injection may cause a decrease in steam production by suppressing hot recharge from depth or replacing lateral recharge by colder injected water. For hot-water reservoirs the effect of different well configurations on the production performance is examined with a model of the East Mesa field and the results show that deep far-infield reinjection provides an optimum strategy that supports reservoir pressures without causing an early thermal breakthrough. The impacts of different rates of infield and outfield reinjection on two-phase liquid-dominated reservoirs are investigated by using a model of Wairakei- Tauhara. The results show that outfield reinjection is a safe method for disposing of water. A high rate of infield reinjection prevents boiling in the reservoir and causes a drop in the production enthalpies. A significant decline occurs in the surface features which are close to the injection zones. Reinjection infield of 25% of the separated geothermal water appears to be a good strategy since it does not cause a significant pressure or temperature decrease. For two-phase vapour-dominated reservoirs reinjection impacts on steam production are investigated by using a model of Darajat. Investigation of various production/reinjection schemes show that; reinjecting 50% of the condensate above the production zones increases steam production significantly. However for higher reinjection rates, the steam production rate may decline owing to the breakthrough of cold reinjected water. If the production zones are deeper, reinjection is much more beneficial. Introducing a larger number of production and reinjection wells scattered throughout the field increases the reservoir life.

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  • Human Determinants of Motor Vehicle Driver Injury in a New Zealand Cohort Study Involving 108 741 Person-Years of Follow-Up

    Whitlock, Gary (2000)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. Background Motor vehicle driver injury is a leading cause of injury, disability and premature death in New Zealand, but only limited data are available about the risks associated with several potentially important human determinants of driver injury. Objective The objective of this research was to investigate associations of driver injury with socioeconomic status (as indicated by educational level, occupational status and neighbourhood income), marital status, handedness, body weight and snoring status. Design A cohort study with prospective and retrospective outcomes Participants 10 525 participants were recruited from two sources: a nationwide multiindustry workforce (n = 8008) and a random sample of the Auckland metropolitan electoral rolls (n = 2517). Twenty eight percent of the study participants were females, 10% were Maori, 5% were Pacific Islands people, and 85% were European or other ethnicity. The ages at baseline ranged from 16 to 88 years (mean 44 years). Data Collection and Analysis Driver injury was defined as an injury received while driving a motor vehicle (e.g. a car or motorcycle) and severe enough to cause death or hospitalisation. Outcome data for the period from January 1988 to June 1998 were obtained from the New Zealand Health Information Service. Baseline data on exposures and confounders were collected in 1992-93. Data on educational level, occupation (coded using the International Socioeconomic Index), domicile address (used to identify median neighbourhood income), social marital status, handedness and snoring status were obtained at baseline by questionnaire. Body weight was measured at baseline by research assistants. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox proportion hazards regression. The HRs reported below were all adjusted for age and gender, except those for body weight, which were adjusted for gender and alcohol intake (there was little evidence of confounding by age). Results 139 driver injury cases were observed during 108 741 person-years of follow-up. Increased relative risks of driver injury were observed among participants in the lowest approximate quartile of occupational status (HR: 4.17; 95% CI: 2.31-7.55), participants who had attended secondary school for two to three years (HR: 2.15; 95% CI: 1.37-3.37) or for less than two years (HR: 2.26; 95% CI: 1.34-3.81), never-married participants (HR: 1.97; 95% CI: 1.29-3.01), participants who weighed less than 70 kilograms (HR: 2.24; 95% CI: 1.34-3.77), and participants who weighed more than 110 kilograms (HR: 2.18; 95% CI: 0.99-4.83). There was little evidence that driver mJury risk was associated with neighbourhood mcome, handedness or snoring status. Conclusions Occupational status, educational level and marital status appear to be determinants of driver injury. Body weight may also be a determinant of driver injury, but further research is required to corroborate or refute this hypothesis. This study did not have sufficient statistical power to exclude the possibility of weak associations with neighbourhood income, handedness or snoring status. The absence of an association with snoring status may have been partly or totally accounted for by misclassification of that variable. These findings identify high-risk groups to which driver injury countermeasures could potentially be targeted.

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  • Roles for Cation-Chloride Cotransporters in Maintenance of Lens Volume & Transparency

    Chee, Kaa-Sandra Nardia (2006)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. Visual acuity is reliant on lens transparency. In diabetic cataract it is well known that the ability of the lens to effectively regulate its volume is disrupted. This results in a localised zone of cellular damage, which distorts the precise tissue architecture of the lens producing light scattering, loss of transparency, and eventually blindness. The volume regulatory mechanisms disrupted in cataract formation are unknown. Therefore the major goal of my thesis is to provide a better understanding of transport systems responsible for controlling the volume of the normal lens. This information is urgently required if we are to understand the processes that initiate diabetic lens cataract. My thesis classifies for the first time the presence and involvement of members of the cation-chloride cotransporter superfamily (CCC) in the maintenance of lens volume and transparency. The potassium-dependent chloride cotransporters (KCCl, 3, 4), the sodium-dependent potassium chloride cotransporters (NKCCl), and the sodium-dependent chloride cotransporters (NCC) were identified in the lens at the transcript and protein levels using RT-PCR and Western analysis respectively. Immunocytochemistry was performed to map the spatial distributions of the different transporters. This analysis showed that each isoform had distinctive spatial distributions. KCC1,3 and 4 were differentially expressed in the cortex but only KCC4 was found in the core. NKCC1 and NCC were also present in the cortex but only NCC was located in the core. To assess the functional activity of these different transporters organ cultured lenses were exposed to specific inhibitors. DIOA mediated inhibition of KCC's resulted in peripheral cell swelling suggesting a role in ion efflux. In contrast, bumetanide inhibition produced a deeper zone of extracellular space dilations suggesting that NKCC mediates ion influx in differentiating fibre cells. The inhibition of NCC with thiazide produced inconclusive results. Taken together this molecular and functional data indicates that the above members of the CCC family mediate spatially distinct chloride influx and efflux pathways in the lens. This information was used to develop an integrative model of the transport processes in the lens. The complex and dynamic nature of these transport systems are illustrated and highlight, the integrated functions of these spatially distinct transporters to maintain the volume set point of the fibre cells. These transport processes are involved not only in steady state volume maintenance, but have roles in cell growth and elongation, and activation under hypotonic stress conditions are elucidated. As well as contributing to a more comprehensive understanding of normal lens volume maintenance, my results have provided a novel theory into the combination of both osmotic and oxidative stresses imposed on the lens under hyperglycaemic trauma. Along with the cotransporters isolated in this thesis, the mechanisms for their control can also be marked as potential targets for innovative anti-cataract therapies.

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  • Influences on Midwifery Practice for the Management of Women in Labour

    Freeman, Lesa Maree (2004)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. The research comprises a series of three studies to explore the practice of midwives ascertain what factors influenced midwives' decision making during the management of labour, and the partnership relationship between the midwife and the woman. A cross sectional design was employed using the predominant methods of interview, questionnaires and thinking aloud tape recordings as triangulation of data. Sample size comprised 104 independent, team and hospital based midwives who were providing labour care to 100 low obstetric risk nulliparous women in the Auckland metropolitan area, New Zealand. Results of this research identified that numerous factors both intrinsically and extrinsically had the potential to influence midwifery practice. The practice of the midwives in providing the labour care was found to be relatively homogenous despite the style of care provided (independent, team, or hospital based). On the other hand, the setting in which the majority of midwives practised (mainly large obstetric hospitals) identified practice influenced by the medical model of care. The influence of technology and the medical model of care, however, did not impact on the women working in partnership with the midwives. This was found to have occurred because the midwives adopted a humanistic approach to care, utilising technology alongside relationship-centred care. In determining what influenced midwives working in partnership with women, it was found that little emphasis was placed on the need for the midwives and the women to have equal status in decision making. Also, it was not deemed essential to have continuity of carer to achieve a relationship of partnership. Birth plans were found to be a beneficial tool for the sharing of information and structuring discussion. However, to assist women to express their preferences and be involved in the decision making process it is proposed that this could be achieved through a conceptual model of shared decision making. This shared decision making model meets the core objectives outlined in Changing Childbirth of continuity, choice, and control, and provides a partnership framework for midwives and women to recognise and utilise differences in their experience and knowledge to achieve their aims.

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  • Dynamics of benthic invertebrate communities in a northern New Zealand kauri forest stream ecosystem

    Towns, D. R. (1976)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. The structure and function of benthic invertebrate communities in the Waitakere River, a kauri forest stream ecosystem, was studied in association with physicochemical parameters from May 1973 until March 1976. Emphasis was placed upon life histories of the dominant species, so that changes in community structure along the stream could be characterised. Analysis of vegetation along the forested watercourse showed a predominance of podocarps and kauri (Agathis australis) in the canopy, with tree ferns dominating in the subcanopy. As the stream flowed into open farmed areas, algal blooms, which were mainly present in summer in some forested sites, became more widespread and persistant. These appeared to influence the composition of the invertebrate communities. Physicochemical analyses of water from several sites in the Waitakere River and its tributaries (from January to December 1974, and in July 1975 and February 1976) provided no evidence that algal blooms could be associated with nutrients derived from agriculture. In the classification of Williams (1964) the waters were "calcium poor" (generally species), life history patterns and the presence of spatial and temporal overlap of related species (members of the genus Deleatidium). It is suggested that most of these characteristics occur throughout New Zealand, and are related to the types of detritus entering New Zealand streams, and the effects of long geological isolation.

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  • Sponge lipids

    Lawson, Mishelle Patrice (1984)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. The fatty acid content of 30 species of Porifera, including samples of Hexactinellida and Lithistida for which no fatty acid data previously existed, have been examined. Sponges are unique among animal phyla in diversity of fatty acids with generally high levels of LCFAs (C24-30), high unsaturation (mainly polyunsaturation), and high incidence of branched and odd chain fatty acids. Further, peculiarities in the proportions of individual acids of particular chain lengths distinguish the phylum. Hexactinellid fatty acid traits corresponded closely to those of Demospongiae while the calcareous species was atypical in exhibiting comparatively low levels of LCFAs and unsaturation. Seasonal and geographical influences on components of the fatty acid profile limit the extent to which this information can be utilised in a chemotaxonomic sense. The major trends in seasonal variation of fatty acid content were in an increase in the levels of unsaturated fatty acids and a decrease in the levels of LCFAs during winter. The effects were less pronounced in a subtidal than intertidal species and are considered to be related to environmental temperature. LCFAs predominated in the phospholipids but also were present in high amounts in neutral lipids. The major changes in fatty acid content of the total lipid with season were reflected in the fatty acids of the phospholipids. Also, LCFAs were concentrated in cellular membranes of the sponge. Temperature-induced seasonal changes in LCFA and UFA composition could be explained as an attempt to maintain .the membranes from which these acids originate, in an optimal state of physico-chemical function across the environmental temperature range. This interpretation is supported by observation of an increased content of higher melting point lipids in the sponge in summer. The sensitivity of sponge membranes to temperature was demonstrated by thermal-induction of phase separations in membrane lipids. A major phase separation in both isolated lipids and membranes occurred within a ca. 8 °C of the normal growth temperature range of the sponge. It indicated that membrane lipids exist in a fluid state in the living sponge so that any variation in environmental temperature would affect the lipid fluidity of the membrane and hence physiological membrane processes. This also lends support for some control being exerted on the lipid fluidity of sponge membranes. Any such control must be non-behavioural since sponges are poikilotherms. Minor changes in the proportions of different phospholipids with season were indicated and are also likely to affect the physical properties of membranes which contain them. In general, the lipid yield from sponges as a proportion of the total dry weight is highly dependent on the skeletal composition, specifically the ratio of the structural to living tissue. Therefore lipid yield is not a reliable parameter for classifying sponges. The occurrence of terpenoid metabolites has proved more informative taxonomically and characterised those groups with a low sterol content, e.g. Dictyoceratida. A coincidence of occurrence of terpenoids and high levels of C25 of fatty acids was noted.

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  • Ecology and Conservation of The Ouvea Parakeet, Eunymphicus cornutus uvaeensis (Loyalty Islands, New Caledonia)

    Robinet, Olivier Louis (1997)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. The Ouvea Parakeet Eunymphicus cornutus uvaeensis, is an endangered bird endemic to Ouvea, Loyalty Islands, in the New Caledonian archipelago. Its population is estimated to be 300-600 birds, mainly in patches of forest in the north, with few parakeets in the centre and the south of the island. Its main habitat is high forest mixed with Melanesian fields. Within habitat distribution is very patchy, with an apparent site attachment during the breeding season. Radio tracking revealed that the home range of juveniles was small, and no dispersal was observed. The diet of the parakeets comprises the seeds and fruits of more than 23 plant species, including Ficus spp., Carica papaya and Rhamnella vitiensis. These plants have a long and asynchronous fruiting season, leading to an apparent abundance of food during the year. The number of breeding pairs was correlated with the density of potential nest sites in the three study areas, suggesting a nest site limitation. The length of the breeding season (August until January) allows the occurrence of double clutches. The parakeets nest in secondary cavities of only five species of trees (90% n Syzygium pseudopinnatum and Mimusops elengii). The clutch size is 2.9 eggs (range 2-4), of which on average 2.6 chicks hatch, 1.65 fledge, but only 0.75 per breeding pair is still alive 30 days after fledging. The main causes of loss are starvation of the third sibling due to hatching asynchrony, human harvest, and raptor predation after fledging. Ouvea is free of Ship Rat Rattus rattus and Norway Rat R. norvegicus. Kiore R. exulans, the rat present, is responsible for only a few predations at nests. The main predators are the Brown Goshawk Accipiter fasciatus, and humans that capture chicks to sell them as pets. 15-30 chicks are still captured every year and sold outside Ouvea. A population viability analysis of the Ouvea Parakeet shows that, with the current carrying capacity, this harvest is not sustainable and would eventually lead to extinction. Long-term survival would be best secured by establishing another population of 4-500 birds in the south of Ouvea, by increasing carrying capacity through habitat protection, nest site provision and restoration, decreasing the harvest and preventing the introduction of Ship Rat in Ouvea.

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  • A spore atlas of New Zealand ferns and fern allies

    Large, M. F. (1989)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. This work constitutes a detailed study of the spores, of the ferns and fern allies, both native and adventive, which grow in New Zealand, from the Kermadec Islands in the North, to the Chatham Islands in the East and the Subantarctic Islands in the South. Twenty live families with sixty five genera, two hundred and eleven species (of which c.20 are introduced) and three subspecies are included. Seven species are heterosporous the remainder are homosporous. Trilete spores are found in c.104 species representing c.30 genera. Perine is present in most taxa (with the exception of Gleichenia) and ranges from the large and sac-like form as seen in Cyathea smithii, to the thin and reduced form seen in Adiantum. Monolete spores are found in c.109 species representing c.37 genera (two genera are included twice, Isoetes which has trilete megaspores and monolete microspores and Lindsaea which has both monolete and trilete species). Perine is present in most taxa (except Sticherus spp.) and ranges from a fine deposit as seen in the Psilotaceae, to an enlarged form, heavily winged, as seen in the Aspleniaceae. Sculpture in all taxa (with the exception of the Lycopodiaceae and some members of the Ophioglossaceae, which may have ornamentation distributed distally), is present on both distal and proximal faces. One adventive taxon Equisetum arvense L. has an unusual circular laesura and elaborate elaters. Light micrographs of acetolysed and fresh spores along with scanning electron micrographs, are included for each taxon. Keys presented, are based on gross spore morphology and are applicable to fresh and acetolysed material. Descriptions include a list of synonymous species, details of spore shape, laesura/ae details, perine/exine sculpture and thickness (where sections allow), size (measured from n=50 spores per population), for samples treated with cotton blue (lactophenol aniline blue formula), mounted in glycerine jelly and acetolysed samples, mounted in silicone oil. Percentage size differences for acetolysed material mounted in glycerine jelly are also noted, along with previous spore dimensions recorded in the literature. Descriptions also contain chromosome number, where known, a list of previously recorded descriptions, a brief indication of geographic location and a list of vouchers for each sample. Experiments on the size and morphology of fern spores in reaction to different preparation techniques are discussed. Fresh spores of seven species, four trilete (Adiantum fulvum, Cyathea smithii, Hymenophyllum flabellatum and Lycopodium volubile) and three monolete (Blechnum chambersii, Paesia scaberula and Tmesipteris elongata), were assessed wth regard to the effect of three standard pretreatments (lactophenol aniline blue, 10% KOH, acetolysis) and two mounting media (glycerine jelly and silicone oil). Changes in morphology and size of the various wall layers were noted in comparison to spores observed fresh in water. Results indicate that variation includes shrinkage e.g. silicone oil and expansion of both exine and perine in glycerine jelly. Both effects are modified by previous treatments.

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  • Aspects of the structure of the Ùa Pou dialect of the Marquesan language

    Mutu, Margaret (1990)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. Thesis now published as a book. Margaret Mutu with Ben Teʻikitutoua (2002). Ùa Pou : aspects of a Marquesan dialect. Canberra, ACT: Research School of Pacific and Asian Studies. ISBN 0858835266. This thesis is made up of three parts; the first is an outline and discussion of the various approaches taken in the description of Polynesian languages in the last 30 years. It provides background discussion of the model of description used in the rest of the thesis. The second deals with the phonology of the 'Ua Pou dialect, concentrating in particular on two areas; the phonetics of the glottal stop phoneme, and penultimate vowel extension. The latter is a feature which has received no mention in any literature to date but is the most noticeable suprasegmental phonetic difference between the Marquesan dialects and the other Eastern Polynesian languages. The last four chapters describe the structure of phrases in the 'Ua Pou dialect. The first two of these deals with the centripetal particles of the noun and verb phrase respectively, that is, the particles within phrases which modify the base of that phrase. Particles which relate phrases to other phrases, that is, the prepositions and ai, are dealt with separately in the last two chapters since their description requires some comments on the syntax of the language.

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  • The Management of Senior Managers: How Firms in New Zealand Acquire, Defend and Extract Value from their Senior Managerial Resources

    Gilbert, John (2006)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. The main aim of this study was to develop an understanding of current practice in New Zealand firms with regard to the management of managers, in particular the senior management team consisting of the CEO and direct reports. Although theory drawn from organizational economics, human resource development and strategic human resource management do provide useful perspectives, there is not, as yet, a well developed or coordinated theory on the management of managers. In this study a theoretical framework is developed, which identifies three broad goal domains for the management of managers and the key strategic tensions that firms may have to deal with in order to achieve their goals within these domains. The theoretical framework also proposes a taxonomy of company styles that describes different patterns of practice that might be expected in firms at various stages of development or in different contexts. The empirical research is centred on case studies of practice in four mid-sized New Zealand firms selected to represent a cross-section of established companies in different sectors and with some variation in patterns of ownership. The main findings are that current practice is largely consistent with the predictions of the theoretical framework and that the firms in the study face pronounced challenges with regard to the recruitment and retention of managers. In particular, the difficulties are compounded by the relatively shallow pool of talent available in a small economy, which makes it difficult for firms to establish robust managerial internal labour markets capable of supplying the bulk of the firms' senior managerial needs. Other findings of note are that there is little evidence of clearly perceived agency issues of the kind raised by the organizational economics literature and that processes and systems for identifying managerial talent in general, and for developing managers at the senior level, are not well developed. The broad conclusions are that firms in a small economy face particular difficulties in making the transition from an emergent stage to having fully evolved internal capabilities to bring managers with superior talent through to senior positions.

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  • Productivity improvement in the New Zealand heavy engineering industry

    Seidel, R. H. A. (Rainer H. A.) (1988)

    Doctoral thesis
    The University of Auckland Library

    Restricted Item. Print thesis available in the University of Auckland Library or may be available through Interlibrary Loan. An analysis of the industrial productivity of New Zealand heavy engineering companies is presented, and methods for improving the overall productivity of the heavy engineering industry and similar industries with job-shop type production are developed. The industry's productivity problems had been obvious for years. However, due to the lack of data and inadequacy of existing productivity improvement approaches, it had never been possible to quantify the extent of these problems, to analyse their causes and to develop methodologies for long-term improvement. The present investigation consists of two major aspects. The scientific element is concerned with the development of a methodology for productivity improvement appropriate to the situation of heavy engineering in New Zealand. This is supported by practice-oriented work in the industry, consisting of data acquisition activities in general, and of pilot studies in selected companies in order to assemble, analyse and evaluate specific data on productivity problems, and to apply and test the results thereof. The development of a methodology for productivity improvement is based on an extensive survey of literature on productivity measurement and improvement methods. The results of this survey, which was performed in parallel with the collection of industrial data, indicate that existing methods are not adequate to satisfy the requirements of productivity improvement in the local heavy engineering industry. On this basis, in-depth pilot studies in ten heavy engineering companies were performed. The objectives and methodology of these pilot studies are described in detail, as their results have a sizeable impact on the overall methodology chosen for this research. One of the most important conclusions drawn from the pilot studies is that productivity problems in the New Zealand heavy engineering industry cannot be solved by concentrating solely on workshop fabrication and technological factors. Generally these problems have complex cause-and-effect structures, and a multitude of non-technological factors from outside the workshop are involved. In order to account for these interrelated factors, a systems engineering approach was used, which offers a suitable basis for a productivity improvement methodology applicable to the situation as identified in the pilot studies. A main step in the system engineering approach is the development of a systems model which is used for structuring the complex inter-relationships found in practice. On the basis of this systems model of heavy engineering productivity a Productivity Assurance Programme is developed. This programme combines elements of quality assurance methods and the 'productivity cycle' principle of continuing improvement. The main elements of the Productivity Assurance Programme are matrices developed for the evaluation of the requirements of productive heavy engineering operation, and for the analysis of the productivity levels of the company where they are applied. The combination of these aspects provides a decision base on which organisational improvements can be founded. Due to its modular structure and the flexibility in defining specific productivity requirements, the applicability of the Productivity Assurance Programme is not limited to New Zealand heavy engineering companies, but also covers other job shop type industries with similar productivity problems. I case study illustrates the application of the Productivity Assurance Programme in practice.

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