8 results for Scholarly text, UC Research Repository

  • Project Management Internship in Post-Earthquake Christchurch: A review of experiences gained and lessons learned

    Helm, Benjamin (2013)

    Masters thesis
    University of Canterbury Library

    This report discusses the experiences gained and lessons learned during a project management internship in post-earthquake Christchurch as part of the construction industry and rebuild effort.

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  • The effect of the Canterbury earthquakes on alcohol consumption and motivations for drinking among psychologically resilient individuals

    Marie, Leila Michele Anastasia (2014)

    Masters thesis
    University of Canterbury Library

    Individual responses to natural disasters are highly variable. The psychological and behavioural response trajectories of those who manage to cope well with adverse life events are in need of further investigation. Increased alcohol use is often observed in communities exposed to mass traumas, particularly among those exposed to severe levels of trauma, with males drinking more than females. The current study examined patterns of alcohol use and motivations for drinking among a sample of psychologically resilient individuals with varying levels of exposure to the Canterbury earthquakes (N = 91) using structured and semi-structured interviews and self-report measures. As hypothesised, there was a significant increase in alcohol consumption since the earthquakes began, and males reported significantly higher levels of pre-earthquake and current alcohol consumption than females. Contrary to expectations, there was no association between traumatic exposure severity and alcohol consumption. While participants reported anxiety-based coping motives for drinking at levels comparable to those reported by other studies, depression-based coping motives were significantly lower, providing partial support for the hypothesis that participants would report coping motives for drinking at levels comparable to those found by other researchers. No gender differences in drinking motives were found. As expected, current alcohol consumption was positively correlated with anxiety and depression-based coping motives for drinking. Psychological resilience was not significantly associated with alcohol use, however resilience was negatively associated with depression-based coping motives for drinking. These findings have inter-generational and international implications for post-traumatic intervention.

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  • "Western thoughts, Eastern feelings": A study of filial piety and elder mistreatment among Korean immigrants in New Zealand

    Park, Hong-Jae (2011)

    Doctoral thesis
    University of Canterbury Library

    Thesis available in print.

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  • An Independent Review of Project Management Processes for CERA’s Port Hills Land Clearance Programme

    Patterson, Todd Keith (2014)

    Masters thesis
    University of Canterbury Library

    This report to RCP Ltd and University of Canterbury summarises the findings of a 5 month secondment to the CERA Port Hills Land Clearance Team. Improvement strategies were initiated and observed. The Port Hills Land Clearance Programme is the undertaking of the demolition of all built structures from the Crown’s compulsory acquired 714 residential red zoned properties. These properties are zoned red due to an elevated life risk as a result of geotechnical land uncertainty following the 2011 Canterbury Earthquakes.

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  • SYNTHESIS AND COMPLEXES OF BRIDGING HETEROCYCLIC LIGANDS

    Rajan, Siji (2014)

    Doctoral thesis
    University of Canterbury Library

    Ligand–mediated coupling between metal centres is of fundamental importance in inorganic and materials chemistry. Bridging ligands involving azo groups as coordinating π–acceptors can yield complexes with interesting properties. This thesis describes the synthesis of a series of N–heterocyclic compounds containing the azo functionality, designed for potential coordination to the metal through the azo nitrogen and a N–heterocyclic ring. The azo ligands are divided into four categories; ligands based on azobispyridines, ligands containing pyrimidine and fused aromatic azine groups and ligands capable of coordinating in a bis–tridentate fashion to the metal centre. Ligands containing flexible imine subunits connected directly, or through different spacers, are also discussed. Overall twenty one ligands were synthesised, six of which are new compounds. The coordination and metallosupramolecular chemistry of these ligands with ruthenium(II) and silver(I) metal atoms was investigated. A total of thirty five ruthenium(II) and eleven silver(I) complexes were prepared, of which thirty eight were characterised by X–ray crystallography. Mononuclear and dinuclear ruthenium(II) complexes were synthesised and characterised by a combination of spectroscopic and structural techniques. UV/Visible absorption studies and electrochemical methods were used to investigate the nature of metal–ligand and metal–metal interactions. In the mononuclear Ru(II) complexes, N–heterocyclic azo ligands act as chelating ligands forming five–membered chelate rings involving azo–N and heterocyclic–N atoms. The non–coordinated pyridine ring of the azo ligand is twisted with respect to the azo–N atom and is directed towards the adjacent bipyridine rings. Studies reveal that these azo ligands posses extremely low–lying π*–orbitals and are electron deficient. X–Ray structural analysis of the dinuclear complexes revealed short inter–metal separations of ca. 4.9 Å and electrochemical studies indicate that these ligands mediate very strong interactions between the metal centres , due to the excellent π*–acceptor properties of the azo functionality. Varying the pyridine ring of the azo ligand to pyrimidines and fused N–aromatic rings has a considerable effect on the electronic properties of these complexes. Incorporation of a pyrimidine ring facilitates the stabilisation of azo anion radicals and leads to the formation of diruthenium(II) species, bridged by radical species. The X–ray crystal structures of both these complexes were determined. The use of the hexadentate ligands coordinating in a bis–tridentate manner mediate even stronger communication between the two ruthenium centres. Ligands containing bis–pyridylimines result in weaker coupling between the metal centres in dinuclear ruthenium(II) species. A complete absence in the inter–metal communication was observed with increasing the distance and/or flexibility between the two pyridylimine units, contrary to a previous reported claim. Reaction with different silver(I) salts afforded an array of one–dimensional coordination polymers and a discrete dinuclear complex depending on the coordination strengths of the anions. The metallosupramolecular assemblies obtained were characterised mainly by X–ray crystallography, elemental analysis and mass spectrometry.

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  • Mating strategies and sperm competition in New Zealand geckos (Family Gekkonidae).

    Todd, Amanda Claire (2003)

    Doctoral thesis
    University of Canterbury Library

    Most species of reptile studied to date have polygynandrous mating systems and possess specialised sperm storage regions. Consequently, there is a high potential for sperm competition in this group. Using comparative analyses, I examined the level of sperm competition in New Zealand geckos and how this has influenced the evolution of their reproductive morphology. Across lizards and snakes, there was more than a 40-fold variation in relative testis size. New Zealand geckos fell in the middle of this range and lacked sexual dimorphism in head size, suggesting that most species have polygynandrous mating systems. I confirmed this for one species, Hoplodactylus maculatus, which is gregarious, lacks territoriality and has a courtship pattern that suggests a high level of promiscuity for both sexes. I found that hemipenis size in New Zealand geckos was positively correlated with relative testis size, suggesting that sperm competition has resulted in the evolution of larger intromittent organs. However, the surface features of the hemipenis were relatively conservative across species. Although there was no relationship between sperm length or putative sperm storage site (SST) morphology and relative testis size, species with fewer SSTs, and thus more intense sperm competition, had longer sperm. H maculatus males produced two types of sperm which differed not only in length but also in fertilising capacity, the short morph lacking DNA. This is the first known example of such sperm polymorphism in a vertebrate and may have evolved in response to sperm competition, the non-fertilising morph potentially helping to block the sperm of rival males or filling sperm storage sites. The motility of these short sperm was positively correlated with temperature; however, at higher temperatures motility declined with time, suggesting a trade-off between motility and longevity. Such temperature influences on male reproductive physiology have important implications for males of ectothermic species under sperm competition.

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  • Characterisation and Control of 3-Deoxy-D-arabino-heptulosonate 7-phosphate Synthase from Geobacillus sp

    Othman, Mohamad (2014)

    Masters thesis
    University of Canterbury Library

    3-Deoxy-D-arabino heptulosonate 7-phosphate synthase (DAH7PS) catalyses the first step of the shikimate pathway, responsible for the biosynthesis of aromatic amino acids. This pathway is found in microorganisms, plants and apicomplexan parasites and its absence in mammals makes it a viable target for antimicrobial drug design. DAH7PS enzymes differ in the regulatory machinery that decorates the catalytic (β/α)8 barrel. Some DAH7PS enzymes are fused to chorismate mutase (CM), another enzyme in the shikimate pathway. This fusion protein is allosterically regulated by chorismate (CA) or prephenate (PA), the precursor of tyrosine and phenylalanine. It has been suggested that DAH7PS enzymes evolved these extensions to the core barrel for the sole purpose of regulation. Geobacillus sp DAH7PS (GspDAH7PSWT) is a thermophilic type Iβ DAH7PS enzyme with an N-terminal CM domain fused through a linker region. This thesis describes the functional characterisation work carried out on GspDAH7PSWT, in attempt to help determine how DAH7PS enzymes evolved such diverse methods of regulation. Chapter 2 describes the functional characterisation work carried out on the catalytic and regulatory domains of GspDAH7PSWT. The enzyme demonstrated both DAH7PS and CM activities with the DAH7PS domain determined to be metal dependent and most activated by Cd2+. PA completely inhibited the catalytic activity of GspDAH7PSWT, and AUC demonstrated an equilibrium exists between the dimeric and tetrameric quaternary states of the enzyme in solution. Chapter 3 describes the domain truncation of GspDAH7PSWT carried out at the linker region in order to obtain two separate protein domains, the catalytic domain lacking the N-terminal domain (GspDAH7PSDAH7PS) and the regulatory domain without the catalytic domain (GspDAH7PSCM). Both variants were fully characterised, and information obtained from each domain was compared to the respective catalytic and regulatory domains of the wild-type enzyme, which was also characterised. Like GspDAH7PSWT, GspDAH7PSDAH7PS showed greatest activation in the presence of Cd2+, with other metals having varying effects on activation rates and stability of the enzyme. Both truncated variants followed Michaelis-Menten kinetics where GspDAH7PSDAH7PS was found to be more active than GspDAH7PSWT and unaffected by PA, whereas GspDAH7PSCM was a less efficient catalyst than the CM domain of GspDAH7PSWT. AUC demonstrated that in solution an equilibrium occurs between the monomeric and tetrameric oligomeric states of GspDAH7PSDAH7PS. Chapter 4 summarises the findings of the thesis along with future directions of this research, combining the results obtained and expanding upon them. It is concluded that the catalytic regulatory CM domain supports both protein structure and allosteric regulation of GspDAH7PSWT

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  • Novel biomarkers for diabetic patients at risk of developing secondary complications.

    Orban, Thomas (2015)

    Masters thesis
    University of Canterbury Library

    Diabetes is a chronic, incurable disease characterized by chronic hyperglycemia. Patients who control their diabetes poorly are at risk of developing long-term complications, such as cardiovascular diseases, renal failure and retina damage. Glycated hemoglobin (HbA1c), formed by the reaction of glucose with hemoglobin, is considered the gold standard for the monitoring of glycemic control, but it does not discriminate between the different types of secondary complications associated with diabetes. Diabetes and its complications are linked to oxidative stress and the resulting lipid peroxidation produce reactive aldehydes including acrolein. Acrolein forms adducts with nucleophilic residues of proteins, which can be used as biomarkers of oxidative stress. It is hypothesized in the present study that specific adducts of acrolein with hemoglobin could be used as reliable biomarkers for secondary complications linked with diabetes. In this context, reactions of acrolein with the two nucleophilic amino acids cysteine and lysine have been studied. The formation of adducts was confirmed for both of these amino acids, and lead to the discovery of the novel compound FTT-cysteine. Studies on hemoglobin itself were conducted in order to understand how acrolein influences the structure and function of this protein and where the preferential sites of modification were located. It was concluded that acrolein does not significantly alter the structure of hemoglobin and actually tends to stabilize it due to the formation of internal cross-links. MS studies revealed that both the single addition of acrolein and the formation of the aromatic compound MP-lysine, arising from reaction with two molecules of acrolein, occur in hemoglobin samples. ELISA tests were developed that could successfully determine the presence of naturally forming hemoglobinacrolein adducts in vivo. X-ray crystallography could show the presence of extra electron density in the vicinity of Cys 93 on the β subunit. A proteomics search determined the sites of preferential reaction on hemoglobin, one of which is Cys 93. These results paved the way for the design of two novel synthetic hexapeptides, Ser-Ala-Gln-Val-Lys-Gly and Leu-His-Cys-Asp-Lys-Leu,whose reactivity towards acrolein was then studied. Both peptides were successfully modified by reaction with acrolein: MS studies revealed the formation of MP-lysine for Ser-Ala-Gln-Val-Lys-Gly and of a single cysteine Michael adduct for Leu-His-Cys-Asp-Lys-Leu. Future work will include the synthesis of 16-residue peptide chains as determined by the results from the proteomics search, against which antibodies will be raised. The antibodies will be used to develop highly specific ELISA assays that will hopefully correlate with secondary complications of diabetes. The outcome of this research could lead to the development of a convenient product that could be used to evaluate the risks that diabetic patients have of developing specific secondary complications.

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