91,047 results

  • Six months exclusive breastfeeding : a relational behaviour influenced by actual and virtual social networks : a thesis presented in fulfilment of the requirements for the degree Doctor of philosophy in Midwifery, Massey University, Manawatu, New Zealand

    Alianmoghaddam, Narges

    Thesis
    Massey University

    Six months exclusive breastfeeding:|ba relational behaviour influenced by actual and virtual social networks : a thesis presented in fulfilment of the requirements for the degree Doctor of philosophy in Midwifery, Massey University, Manawatu, New Zealand

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  • Emotion recognition and intellectual disability : development of the kinetic emotion recognition assessment and evaluation of the emotion specificity hypothesis : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Clinical Psychology at Massey University, Albany, New Zealand

    Godinovich, Zara Angela

    Thesis
    Massey University

    Deficits in social adaptive functioning are a defining criterion of intellectual disability (ID) (American Psychiatric Association, 2013), and a key predictor of social inclusion and subsequent quality of life (Kozma, Mansell, & Beadle-Brown, 2009). Impairment in facial emotion recognition is often cited as the component skill responsible for the social difficulties observed. This position has been formally conceptualised by the emotion specificity hypothesis (ESH; Rojahn, Rabold, & Schneider, 1995), which proposes that individuals with ID manifest a specific deficit in facial emotion recognition beyond that which can be explained by difficulties in general intellectual functioning. Despite apparent widespread acceptance, there is not yet sufficient evidence to substantiate these claims. Moore (2001) proposes that emotion perception capacities may be intact in people with ID, and that reported deficits are instead, due to emotion recognition tasks making extensive cognitive demands that disadvantage those with lesser cognitive abilities. The aim of the present study was to clarify the nature of facial emotion recognition abilities in adults with mild ID. To this end, the Kinetic Emotion Recognition Assessment (KERA), a video-based measure of facial emotion recognition, was developed and a pilot study completed. The measure was designed to assess emotion recognition abilities, while attempting to reduce information-processing demands beyond those required to perceive the emotional content of stimuli. The new instrument was assessed for its psychometric properties in individuals with ID and neurotypical control participants. Initial findings supported the interrater reliability and overarching construct validity of the measure, offering strong evidence in favour of content, convergent and predictive validity. Item difficulty and discrimination analysis confirmed that the KERA included items of an appropriate level of difficulty to capture the range of emotion recognition capacities expected of individuals with mild ID. The secondary focus of the study was to assess how subtle methodological changes in the assessment of emotion recognition ability may affect emotion recognition performance, and in turn provide insight into how we might reinterpret existing ESH literature. To this end, the KERA was also applied in an investigation of the potential moderating effects of dynamic cues and emotion intensity, in addition to the assessment of the ESH. The results offer strong evidence that individuals with ID experience relative impairment in emotion recognition abilities when compared with typically developing controls. However, it remains to be seen whether the observed difficulties are specific to emotional expression or associated with more generalised facial processing. Preliminary findings also suggest that like their typically developing peers, individuals with ID benefit from higher intensity emotional displays; while in contrast, they observe no advantage from the addition of movement cues. Finally, the overarching motivation for the reassessment and improved measurement of the ESH, was in the interests of improving real-world outcomes associated with emotion recognition capacities. Accordingly, emotion recognition data were also interpreted in the context of three measures of social functioning to explore the link between social competence and emotion recognition ability. Results indicated that emotion recognition abilities are linked to outcomes in social adaptive functioning, particularly for females.

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  • Explorations into the nature of insulin binding to oxidized dextran : this thesis was presented in partial fulfillment of the requirements for the degree of Master of Science in Chemistry at Massey University

    Li, Yuming

    Thesis
    Massey University

    The results reported in this thesis comprise an investigation into the conjugation of insulin to oxidized dextran, various release studies from the conjugates, and an attempt to interpret the binding nature of the conjugates. A model system involving the sustained release from insulin-dextran conjugates has been employed in this study. For insulin, up to 3 potential sites only (A1-Gly. B1-Phe and B29-Lys) were expected to bind to oxidized dextran. The rate of release and the maintenance of activity of the released protein are vital to such systems. Success in the interpretation of the binding nature of the conjugate will allow us to investigate its relationship to the rate of release. The desired rate of release for the sustained release of protein could then be achieved, once the projected binding could be obtained. Activation of dextran was achieved by periodate oxidation to give levels of 8%, 16% and 27% oxidized dextran. Insulin was chosen for its relatively 'uncomplicated' structure and few possible sites available for binding with activated dextran. Insulin was bound to the dextran through imine bonds. Complex formation was examined under a wide range of conditions. Initial studies were begun with the determination of a desirable basic molar ratio. A molar ratio of insulin to 8% activated dextran of 10 : 1 arose from this set of experiments. Insulin was bound to 27% activated dextran at pH 7.4, pH 9 and pH 10. In the cases of pH 9 and pH 10, many more lower MW complexes were formed than at pH 7.4. It seemed that the higher the pH of formation, the more crosslinks occurred between an insulin molecule and dextran molecules in the lower MW range. Approximate physiological pHs (pH 7.1-7.8) were used for complex formation in all subsequent experiments. Release studies were carried out under approximate physiological conditions (pH 7.4, 37°C). Immediate release was observed upon isolation by size exclusion chromatography. The greatest release occurred in the first 24 hours for all three activation levels. The higher the activation level of dextran, the lower the level of release. An equilibrium was established after several days' release and studies at 37°C produced the expected result: greater release relative to ambient. A number of studies were carried out with complex after sodium cyanoborohydride had been used to reduce the imine bonds. The first set of experiments on the reduced complexes was enzymatic cleavage studies, which employed trypsin and α-chvmotrypsin. The results for trypsin digestion of the reduced insulin-27% oxidized dextran complex indicated partial binding had occurred at B29-Lys, in combination with full binding at B1 and/or Al. Amino acid analysis results of the isolated complex after trypsin digestion indicated about 90% binding occurred at B29-Lys for the complex, which formed at pH 7.1. The results of α-chymotrypsin digestion study were shown questionable due to its incomplete cleavage. The reduced complexes were analyzed by amino acid analysis. The insulin-27% activated dextran complexes formed at pH 7.4, pH 9 and pH 10 showed similar extents of binding at B1-Phe, indicating B1 might be the prime binding site. There was more binding at B29 and A1 for the pH 9 than at pH 7.4 case. At pH 10 abnormal values arose. The studies for the complexes of insulin with 16% and 27% activated dextran indicated the more highly activated the dextran, the greater the binding at B29 and A1. Trials with the 2, 4-dinitrophenyl-derivativatization method proved to be a useful way to examine the degree of B1 and B29 binding from the amino acid analysis results of complex. The insulin-16% activated dextran complex formed at pH 7.1 was found to be about 100% binding at B1, 60% at A1 and 50% at B29. Oxidative and reductive cleavage studies of A and B chains of insulin and the complex were carried out to investigate the level of A1 binding. After chemical cleavage of the three disulfide bonds in insulin and subsequent chromatography, the amino acid analysis results for the treated complexes indicated a significant proportion of A chain had bound to dextran, i.e. at A1. An estimation of 60-70% of A1 binding was achieved for this study. This exploratory study has shown that varied complex formation conditions such as the level of activation of dextran, pH, and temperature could alter the extent of binding between insulin and dextran molecules. Amino acid analysis of the reduced complex was a useful method to interpret the binding.

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  • "Presumed straight until demonstrated otherwise" : the relationships between sexual identity, heteronormativity, sexual identity development and psychological well-being : a thesis in partial fulfilment of the requirements for the degree of Doctorate in Clinical Psychology at Massey University, Palmerston North, New Zealand

    Bejakovich, Tamara

    Thesis
    Massey University

    The conceptualisation and development of a sexual identity has been debated in the literature. Whether identity is conceptualised as categorical or on a continuum, people with same sex experiences, such as those identifying as lesbian, gay, bisexual, questioning and other (LGBQ+), demonstrate lower psychological well-being than their heterosexuallyidentified counterparts. Some have argued this is a result of the stress associated with minority status; others comment on the influence of the development of a sexual identity divergent of the heterosexist norm. Literature supports both claims, yet inconsistencies exist in the study of the psychological outcomes of those with LGBQ+ identities. The current research intended to alleviate some of these debates with three foundational aims: to explore the placement of the sexual identity categories along the continuum, and incorporate more sexual identity categories in sexual identity assessment, demonstrating respect for diversity; to examine the differences in psychological well-being between people with different sexual identities and in different phases of development; and to investigate how dimensions associated with sexual identity, such as identity disclosure, influence these differences. To do this, the study utilized an online survey incorporating a number of measures. People with different sexual identities were significantly different along the sexual identity continuum. In addition, as suspected, non-binary identities (defined in this research as people not ascribing to either heterosexual or lesbian/gay identities) reported lower levels of well-being. When accounting for differences in identityrelated factors, such as identity uncertainty and disclosure, several of the significant differences were eliminated, and all but one of the remaining significant findings demonstrated reduced effect sizes. Those in the Synthesis phase of individual and group identity development generally reported greater levels of psychological well-being. Once again, when controlling for identity-related factors these differences were reduced or eliminated. Future research should investigate a universal model of sexual identity formation, and should assess identity dimensions in those identifying as heterosexual. Gaining greater understandings in the experiences of people with LGBQ+ identities demonstrates areas to target for interventions in order to decrease the disparities which exist between people with these and heterosexual identities.

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  • Microbial co-existence and stable equilibria in a mechanistic model of enteric methane production : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Mathematics at Massey University, Manawatū Campus, New Zealand

    Wang, Yuancheng

    Thesis
    Massey University

    Globally, 14.5% of all anthropogenic greenhouse gases come from ruminants. One of these is methane, which is produced in the rumen of ruminant animals. Feed is degraded by microbes to produce volatile fatty acids (which are absorbed by the animal) and hydrogen (which is metabolized by methanogens to form methane). The dynamics of hydrogen production and metabolism are subject to thermodynamic control imposed by the hydrogen concentration. Existing models to estimate methane production are based on calculation of hydrogen balances without considering the presence of methanogens and do not include thermodynamic control. In this project, a model is developed based on glucose-hydrogenmethanogen dynamics to estimate methane production and illustrates a co-existence of microbes that employs different fermentation pathways competing for the same food source in the rumen. Glucose was chosen as an example of a fermentable feed component. A thermodynamic term was integrated into a Monod-type model to represent the thermodynamic control of hydrogen concentration on the rates of hydrogen generation and hydrogen metabolism. Results of this model suggest that the microbial community composition and the combination of the different pathways are determined by the rumen environment, biological parameters of the microbes and the feedback imposed by substrate and product concentrations. The mathematical enunciation of this model is therefore consistent with biological expectations. This model could be expanded to include plant polymer degradation rate, feeding level and feeding frequency to explore their effects on methane production. This model could also be integrated into models of whole rumen function to address more complex questions. It would also support experimentation with animals for understanding factors that control methane formation and to explore methane mitigation strategies.

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  • An investigation of some correlates of mature moral judgement : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Education at Massey University

    Whalley, David George

    Thesis
    Massey University

    From Kohlberg's cognitive developmental perspective, moral judgement has been viewed as an aspect of ego development which is related to other aspects of ego development. The purpose of this research was to investigate some possible correlates of mature moral judgement: although some research had been conducted with children practically no research into correlates in adult populations has been reported. A sample of 50 male and 32 female first year teachers' college volunteer subjects was used. Of these, a random subsample of 10 males was used to test the congruent validity of the written questionnaire form of 4 of Kohlberg's (1958) moral dilemma situations devised for this research, with the original interview technique. Using a design counterbalanced for order of presentation with one week retest interval the difference between the measuring devices was found to be non-significant (t = -0.13, p>.55) . The remaining subjects wore randomly assigned to one of two testing orders - 20 males and 16 females to each group. In three testing sessions at 3-4 day intervals both groups were administered the: Kohlberg Moral Judgement Scale (written form). Study of Ethical Attitudes, C.P.I., P.O.I., Study of Values, E.P.I., Californian F-test and Mill Hill Vocabulary Scales. The order of presentation was counterbalanced. Two-way ANOVAs were performed on the data to test for sex or order effects. In the majority of cases no significant effects wore found and so the data was contained to provide a sample n of 72. On scales on which significant differences were found separate analysis of the subgroups was performed. A measure of Piagetian cognitive level was obtained 2 months later by individual testing. Analysis of the Kohlberg scale revealed a high level of stage mixture: only 5.5 percent of subjects had a range as low as 4 stages. Evidence was put forward that indicates that high levels of stage mixture have also been found by others and the conflict between this finding and Kohlberg's theory was discussed. A factor analysis of the item scores revealed 6 factors with eigen values greater than one. Five of these could be interpreted meaningfully in terms of Kohlberg's theory but the second factor was difficult to interpret; it seemed because of its correlations with other measures to be concerned with general sensitivity to ethical issues. The factors were identified as: factor 1 (conflict between obedience to the law and the value of human life), factor 3 (duty vs contractual obligation), factor 4 (spirit of the law), factor 5 (property rights) and factor 6 (power rights vs moral rights). Contrary to Kohlberg's finding but in line with a number of other studies no major moral judgement factor emerged. Correlations between Moral maturity scores and other personality measures were largely non-significant. A correlation of -.30 (p

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  • Further characterization of Dothistromin genes in the fungal forest pathogen Dothistroma septosporum : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Molecular Genetics at Massey University, Palmerston North, New Zealand

    Jin, Hong Ping

    Thesis
    Massey University

    Dothistroma septosporum is a forest pathogen that causes a disease called Dothistroma needle blight. The symptoms are thought to be due to the accumulation of dothistromin toxin produced by D. septosporum. Dothistromin is characterized as a difuranoanthraquinone and shows remarkable similarity to the aflatoxin (AF) and sterigmatocystin (ST) precursor versicolorin B. The similar structure to AF/ST suggests that dothistromin biosynthesis shares biosynthetic steps with the AF/ST pathway. The AF gene cluster in Aspergillus parasiticus and ST gene cluster in A. nidulans have been well characterized. Nine putative dothistromin biosynthetic genes have been identified. One of them, dotA was previously characterized by gene disruption and shown to have a similar function to homologous genes in AF/ST biosynthesis. Two additional putative dothistromin biosynthetic genes, pksA and epoA, were characterized by gene disruption in this study. The inability of the pksA mutants to produce dothistromin indicated that the pksA is a key gene in dothistromin biosynthesis. The feeding of intermediates confirmed that pksA gene product is required for a very early step of dothistromin biosynthesis. The pksA mutants also showed reduced sporulation compared to wildtype, suggesting a relationship between dothistromin production and sporulation. The epoA gene replacements were also obtained successfully by homologous recombination. Both Southern blot and northern hybridization confirmed that the epoA gene was disrupted. However, the epoA mutants did not show any difference to the wild type in three analyses (growth rate, sporulation rate, dothistromin biosynthesis). However it was not possible to rule out a role for EpoA at a very late stage of dothistromin biosynthesis. RACE analysis of the nine identified dothistromin genes characterized the transcription start and stop sites of the genes. Analyzing the putative regulatory protein binding motifs in the untranscribed region of the genes provided clues about the regulation of dothistromin biosynthesis and suggested there might be an aflR-like gene that governs dothistromin biosynthesis. Both the pksA gene disruption and the RACE results suggested that the dothistromin biosynthetic pathway is homologous to that of AF/ST biosynthesis. Further work on the dothistromin gene cluster will help us to understand the evolution of fungal toxin gene clusters.

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  • Fundamentals of Riemannian geometry and its evolution : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Mathematics at Massey University, Palmerston North, New Zealand

    Senarath, Padma

    Thesis
    Massey University

    In this thesis we study the theory of Riemannian manifolds: these are smooth manifolds equipped with Riemannian metrics, which allow one to measure geometric quantities such as distances and angles. The main objectives are: (i) to introduce some of the main ideas of Riemannian geometry, the geometry of curved spaces. (ii) to present the basic concepts of Riemannian geometry such as Riemannian connections, geodesics, curvature (which describes the most important geometric features of universes) and Jacobi fields (which provide the relationship between geodesics and curvature). (iii) to show how we can generalize the notion of Gaussian curvature for surfaces to the notion of sectional curvature for Riemannian manifolds using the second fundamental form associated with an isometric immersion. Finally we compute the sectional curvatures of our model Riemannian manifolds - Euclidean spaces, spheres and hyperbolic spaces.

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  • An investigation of the relationships between social contact (telework) and job satisfaction : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University

    Leung, Jade

    Thesis
    Massey University

    The present study aimed to examine the relationship between the social contact and job satisfaction of teleworkers. Telecommunications and computer technology has enabled the development of work arrangements that allow employees to perform their work at home. This is the basic premise of telework, that work can be conducted away from the office using computers and telecommunications technology to transmit and receive work. Although surveys and anecdotal evidence indicate that social isolation is one of the major reported drawbacks of telework especially for women, there have been no in-depth studies investigating this. It has also been speculated that personality, especially introversion, may be related to workers being satisfied with telework and that having a mentor reduces the social isolation of teleworkers but again, no investigation has been carried out to examine these claims. Seventy-six subjects (35 males and 41 females) answered a self-report questionnaire. Correlational analyses were carried out and findings suggest that the first hypothesis that telework involves low social contact and is not satisfying, was only partially supported. Results indicate that there is only a moderate relationship between job satisfaction and the quality of social contact. The second hypothesis that females would not be satisfied with telework because females have a greater affiliative need was not supported. In fact, it was reverse was found the relationship between social contact and job satisfaction was stronger for male teleworkers. The third hypothesis that extroverts will not be satisfied with telework was supported, the relationship between the quantity of all social contact and job satisfaction was stronger for extroverts than introverts. The fourth hypothesis that telework will be satisfying for those with a mentor could not be investigated due to lack of data. It was concluded that the relationship between social contact and job satisfaction was not as strong for teleworkers as speculated which means that social isolation may not be as great a problem as suggested. However, the small sample size limits the ability to generalise the results to the population and further research needs to be done to develop more sensitive measures for social contact and telework.

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  • An evaluation of the effectiveness of castellated laryngofissure and bilateral arytenoid lateralisation for the relief of laryngeal paralysis in dogs : a thesis presented for the degree of Master of Veterinary Science at Massey University

    Burbidge, Hilary

    Thesis
    Massey University

    In recent years, laryngeal paralysis in dogs, has become a frequently recognised disorder. Various surgical procedures have been advocated to relieve the consequential laryngeal obstruction, but few critical examinations of the effectiveness of these procedures have been attempted. The aim of this study was to determine and compare the efficacy of two of the more commonly used surgical methods (i) castellated laryngofissure with vocal fold resection and (ii) bilateral arytenoid lateralisation in providing an adequate laryngeal airway in dogs after surgically Induced laryngeal paralysis. The laryngeal function of ten adult healthy experimental dogs was assessed by clinical examination, laryngoscopy, blood gas and tidal breathing flow-volume loop analyses prior to and after bilateral recurrent laryngeal nerve resection. Five dogs then underwent a castellated laryngofissure with vocal fold resection and the remaining five, bilateral arytenoid lateralisation. Six weeks later, the laryngeal function of the ten dogs was reassessed using the same investigative techniques. Radiographs of the chest were taken at the start and completion of the experiment on the live dogs to help detect the presence of any co-existent lower respiratory tract disease. An autopsy was performed on each dog. six weeks after surgery, and details of visible changes in the laryngeal structure recorded. After neurectomy, all of the dogs had inspiratory stridor, a hoarse bark and reduced exercise tolerance. Medial displacement of the arytenoid cartilages and vocal cords caused narrowing of the rima glottidis. No abduction of these structures occurred during inspiration. There was a significant fall in arterial oxygen tension and inspiratory airflow recorded on blood gas analyses and tidal breathing flow-volume loop studies, respectively. The degree of relief from the laryngeal obstruction in the neurectomised dogs after castellated laryngofissure with vocal fold resection was variable. Some of the animals still had signs of respiratory embarrassment. The size of the rima glolhdis achieved was either slightly narrower or similar to that seen in the non-abducted. pre-neurectomised larynx of the experimental dogs. No significant improvement in blood gas or tidal breathing flow-volume loop analyses were recorded following the surgical technique. In contrast, bilateral arytenoid lateralisation consistently alleviated the clinical signs of bilateral recurrent laryngeal neurectomy. The rima glottidis width was increased to either the non-abducted, pre-neurectomised size or greater, depending on the position of the lateralisation suture. Furthermore, blood gas and tidal breathing flow-volume analyses recorded a significant increase in arterial oxygen tension and inspiratory airflow, respectively. Although bilaterial arytenoid lateralisation was more efficient than castellated laryngofissure with vocal fold resection in alleviating the laryngeal obstruction caused by bilateral recurrent laryngeal neurectomy, it did have some inadequacies. The fixed abduction of the arytenoid cartilages destroyed the expiratory braking mechanism of the larynx. Furthermore, execution of the surgical technique requires intimate knowledge of the anatomy of the larynx and the surrounding structures and, since the position of the lateralisation suture is imporlant,best results are likely to bo achieved by surgeons experienced with the procedure.

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  • An investigation of cerebral asymmetry, echoic memory, and the stimulus suffix effect : a thesis ... for the degree of Master of Arts in Psychology at Massey University

    Blazina-Young, Elizabeth

    Thesis
    Massey University

    Echoic memory and hemispheric processing of two semantic categories of words were investigated utilizing a stimulus suffix paradigm under four delay conditions. The magnitude of the stimulus suffix effect was evaluated when combinations of concrete and abstract word lists and suffixes were monoaurally presented to the left and right ears. The results showed that the stimulus suffix effect occured for all information presented to both ears but was less pronounced when information was presented to the right ear. A right ear advantage for all information as well as a right ear advantage for abstract information was found. In addition, the right ear showed superior recall of abstract stimulus list and suffix combinations over other list and suffix combinations. Increasing delays between list and suffix presentation led to an increase in recall frequencies for terminal positions in the lists, but this increase was not systematic with delay. Results suggest that the right ear advantage often reported is due to right ear advantage for abstract information, and that echoic memory persists for at least 8 secs. These findings support the dual-trace processing model of hemispheric function and suggest that echoic memory may persist longer than the 2 secs implied by earlier researchers.

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  • Functional analysis of plant Mei2-like proteins : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University, Palmerston North, New Zealand

    Leung, Susanna Chui-Shan

    Thesis
    Massey University

    Molecular techniques were used to analyse the function of a novel class of RNA-bindmg proteins in plants, termed Mei2-like. The biochemical function of this class of proteins is unclear Although the conserved presence of three RNA recognition motifs (RRMs) in all members of the family suggests the importance of an RNA binding activity, the precise biochemical mechanism by which these proteins act is unknown. Genetic and molecular analyses of the founding member of the family. Schizosaccharomyces pombe Mei2p, provide of a conceptual framework for the studies of the plant Mei2-like proteins presented here. Therefore, the aims of this thesis were to 1) study the cellular localisation of Mei2p in plant cells, and 2) deduce the functions of plant Mei2-like genes by identifying the protein(s) that physically interact(s) with Mei2-like proteins. Transient expression of GFP-fused Mei2p in onion epidermal cells was performed to show that Mei2p localised into the nucleus in the presence of meiRNA, a non-coding mRNA. Thus plants seem to share the capacity with S. pombe for meiRNA-dependent nuclear localisation of Mei2p. Moreover, intracellular localisation of one of the plant Mei2-like proteins, TERMINAL EAR-Like 2 (TEL2), was studied in onion epidermal cells. The GFP-fused TEL2 localised into the nucleus without co-expression of any special RNA, suggesting that either some RNA species that assist nuclear localisation of TEL2 are already present in onion epidermal cells, or the mechanism of intracellular localisation of TEL2 is different from Mei2p. The yeast two-hybrid system was utilised to identify protein interactors with TEL2. Six proteins were identified, including the well-studied KORRIGAN (KOR) protein. Based on the proteins identified, speculation is offered on how these proteins interact with TEL2. Since TEL genes are expressed in the central zone (CZ) of meristems, and mitotic activity of cells in the CZ is low, TEL2 may be involved in controlling cell division in the CZ via interactions with these proteins.

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  • Growth and shear loss characteristics of an aerobic biofilm : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Technology in Biotechnology at Massey University

    See, Tiam Teng

    Thesis
    Massey University

    The application of biofilms in fermentation and waste treatment processes has been increasingly considered in recent years due to several inherent advantages over suspended growth systems. For example, they enable higher biomass hold-up providing larger quantity of cell per unit reactor volume which allows high loading rates. The biofilm systems, with fixed or immobilised cells, avoid washout conditions. The often difficult problems of sludge thickening, separation, recycle, and wasting associated with suspended growth systems are eliminated for biofilm systems. However, the major drawback lies in the control of film thickness in order to maintain high reactor productivities. The attached film thickness depends on both the biological parameters such as growth rate, and physical parameters such as hydrodynamic shear. The understanding of the growth and shear loss characteristics is a prerequisite for effective film thickness control. The main objective of this work therefore is to investigate the growth and shear loss characteristics of an aerobic biofilm utilizing phenol in a concentric cylindrical bioreactor. The growth and detachment of the biofilm was studied at different shear stresses, and their relationships were established. Detachment by shear was studied under two different conditions. One was examined simultaneously with growth under a constant shear stress where the biofilm detachment and growth occurred at the same time in the bioreactor. The other was examined via a separate shear test performed on the biofilm initially grown at a shear stress lower than that applied during the test. A method for measuring the torque exerted on the biofilm surface was first developed to enable computation of the related shear stress necessary for the study. The effect of film thickness on torque at film surface for a constant rotational speed was not significant. Shear stress can be conveniently determined from a quadratic relationship between torque and rotational speed for the range of film thickness studied. The substrate consumption is directly proportional to film thickness up to about 0.050 to 0.100 mm only, and beyond that it becomes independent of film thickness. The mass transfer resistance in the liquid phase appears to reach a minimum at shear stress greater than 3.44 N/m2 coinciding with the maximum steady-state substrate removal rate. The shear loss resistance of the biofilm increases with increasing shear stress during growth. The ultimate shear loss rate and shear stress relationship follows approximately: Rs = (40.82 – 2.750+0.1502 – 31.83e-0.610 ) × 10-2 The net growth rate varies with shear stress according to a parabolic function which predicts a shear stress of 19 N/m2 is required to achieve zero net growth. The biofilm-support adhesion must remain stronger than the film layer adhesion, otherwise, detachment will occur at the film-support interface rendering it impossible to control the film thickness.

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  • Fructan biosynthesis in Lolium perenne : tissue, cultivar and temperature effects on gene expression and protein accumulation profiles : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology at Massey University, Palmerston North, New Zealand

    Xue, Hong

    Thesis
    Massey University

    Cultivars of Lolium perenne with high concentrations of water soluble carbohydrates (WSCs) offer opportunities to mitigate greenhouse gas emissions (nitrous oxides) from grazed pastures and improve meat and milk production in livestock. Our previous studies demonstrated that fructan accumulation in the blades of high W SC grasses involves a strong gene x environment interaction. To identify the temperature effects on the expression of high sugar trait in the high sugar cultivars. we conducted a pot trial in climate chambers with temperature regimes set at10/10, 20/10 and 20/20°C (day/night), respectively. Water soluble carbohydrate concentrations, the expression of the key genes and proteins: l-SST (sucrose: sucrose l-fructosyltransferase), l-FFT (fructan: fructan l-fruclosyltransferase), 6G-FFT (fructan: fructan 6G-fructosyltransferase) and l-FEH l-fructan exohydrolases) involved in the fructan biosynthetic pathway of L. perenne were compared in blades and sheaths of three selected high sugar cultivars (P, A and H) and a common cultivar (F) grown under the three temperature regimes. We found that amongst the selected 3 high sugar cultivars, high molecular weight (HMW) WSC content was significantly higher in P and A cultivars, regardless of the temperature regimes. As expected, sheaths contained significantly higher concentrations of HMW WSCs (fructans) compared to leaf blades. The highest WSC contents in both leaf and sheath tissues accumulated at 10/10°C while the lowest accumulated at 20/20°C. Gene expression profiles demonstrated that all four genes studied were more significantly expressed in sheaths compared to blades, and the expression levels were highly correlated with fructan accumulation in this tissue. Low temperature resulted in significant up-regulation of l-SST in sheaths, but not in blades. l-FFT was highly expressed in blades of A and P cultivars. Unexpectedly. 6G-FFT was expressed more significantly in the control F cultivar. but not in the high sugar cultivar P. Protein expression profiles showed that l -SST protein accumulated to high levels in sheaths, whereas protein levels of l-FFT and l-FEH were higher in blades. l-SST protein levels in both blades and sheaths generally increased in plants grown at low temperatures, whereas l-FFT protein was not affected by low temperatures in blades and sheaths, furthermore, in both tissues there was no consistent effect observed between the different cultivars and temperature regimes on l-FEH protein levels.

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  • Explaining the cross-country variation in fiscal multipliers : a Bayesian approach : a thesis presented in partial fulfillment of the requirements for the degree of Master of Business Studies in Financial Economics at Massey University, Albany, New Zealand

    Purushothman, Nanda Kishora

    Thesis
    Massey University

    The effectiveness of fiscal policy is subject to crowding out. For nearly thirty years of annual economic data, we find that the crowding out of fiscal policy occurs through interest rate and exchange rate channels. The three most important determinants affecting the size and sign of fiscal multipliers during recessions worldwide are: (i) exchange rate regime, (ii) monetary policy, and (iii) current account balance. We find statistically significant results that these accompanying policies are the most influential sources of the cross-country variation in fiscal multipliers. Similarly, using an OECD dataset examining both economic expansions and recessions, we find that the three most statistically significant variables affecting fiscal multipliers in this case are: (i) exchange rate stance, (ii) private investment, and (iii) monetary policy. We find that the coefficient of the private investment variable is significantly negative, which is in line with the theoretical predictions. This finding is consistent with the hypothesis that expansionary government spending financed by debt crowds out private investment through rising interest rates.

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  • The effects of drying methods and storage conditions on pea seed (Pisum sativum L.) quality and the relationship between high temperature drying and maize seed (Zea mays L.) stress cracks : this thesis presented in fulfilment of the requirements for the degree of Master of Applied Science (Agricultural Engineering) in the Institute of Technology and Engineering, Massey University, New Zealand

    Thuy, Nguyen Xuan

    Thesis
    Massey University

    High temperature and high relative humidity adversely affect the quality of seeds, and are features of tropical climate. Seed drying and storage are being used increasingly in developing countries to improve seed storage and quality. This study was undertaken to evaluate a range of seed drying methods and storage conditions with the view to selecting an appropriate method(s) for use in tropical countries. Pea (Pisum sativum L.) seeds at three initial seed moisture content (m.c.) of 23.8, 18.0 and 14.5% were dried to 10% seed m.c. before storage. The performances of four different drying methods: artificial dryer (Kiwi Mini) set at 30°C or 45°C, natural sun drying, and in-bin natural ventilation drying were evaluated. Natural sun drying, and in-bin natural ventilation drying were conducted from March to May, 1997, when mean temperature and relative humidity during sunny days were 17°C and 60% respectively. The dried seeds were stored under two conditions: open storage at 20.5°0 and 55% relative humidity (r.h.), and closed storage at 25°C and 90% r.h. for 20, 40, and 60 days. Time and energy consumed for drying by the different methods were determined to compare the drying efficiency when combined with quality of the seed. Deterioration of the seed due to storage conditions and drying methods used was determined by assessing their effects on seed germination, abnormal seedlings, dead seed, hollow heart percentages, and conductivity. Seed samples dried by the Kiwi Mini dryer set at 45°C took 7 hours and those set at 30°C took 17 hours. It took 54 hours with natural in-bin ventilation drying, while sun drying took 37 hours. However, energy consumed when drying seeds at 30°C was 17 kWh, which was more than twice that at 45°C. Seed germination was not significantly different between drying methods, but averaged only 75% because of sprouting damage of the crop prior to harvest. Germinations after open and closed storage for 20 days did not differ, although some differences appeared after 40 days of storage. However, open and closed storage for 60 days significantly reduced seed germination to 54 and 33% respectively. Because seeds are heat-sensitive, drying air temperature and drying rate are particularly important to avoid internal seed breakage, cracking and splitting, fungal growth, and loss of germination and vigour. Selected studies have shown that seed can be dried at high temperature for a short time, followed by tempering to re-distribute moisture and temperature inside the seed, thus reducing the percentage of cracking. Thus, a second experiment was conducted with maize (Zea mays L) to study the impact on seed viability of high temperature drying followed by tempering. Maize at 28.5% initial seed m.c. was dried at 60°C for short periods of 5, 10, 15, 20, or 25 minutes, followed by tempering for 45 minutes at either 30°C or 21°C. This cycle was repeated until maize seeds were dried to 13.0% m.c.. The percentage of cracked seeds, germination immediately after drying, and after an accelerated ageing test, did not differ between 30°C and 21°C tempering. Drying exposure times of up to 10 minutes per cycle at 60°C caused vertical cracks in up to 50% of seeds, but seed germination remained over 90% and seed vigour was also maintained. The percentage of seeds with stress cracks due to high temperature drying (5 - 25 minute cycles) at 60°C followed by tempering had polynomial relationships with seed germination and vigour. Seeds dried at the same temperature without tempering had their germination reduced from 99 to 20%.

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  • A historical study of the search for oil in the Poverty Bay-East Coast district from 1874 to 1912 : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in History at Massey University

    Sharp, Ronald Murray

    Thesis
    Massey University

    This thesis deals with oil exploration in the Poverty Bay East Coast district between the years 1874 and 1912. The Geology of the district is outlined and a brief chronology of events is given. The achievements and problems of boring are related in Chapter I. Chapters III and IV unfold the story of exploration examining company promotion, share holding, public criticism and company expenditure. Chapter V gives brief biographies of most of the men of the district who promoted the companies. The occupations of the promoters are analysed. Public attitudes to the exploration are examined under three themes: the confidence that oil would be found, the question of local or foreign capital; and the benefits Poverty Bay would have received.[FROM INTRODUCTION]

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  • The exploitation of children as soldiers in the Philippines : an analysis of issues and challenges in social work practice : a thesis submitted in partial fulfillment of the requirements for the degree of Master of Social Work at Massey University, Albany, New Zealand

    De Ocampo, Ma. Irene Ordoña

    Thesis
    Massey University

    This study aims to explore and analyze how social workers directly working with child soldiers perceive the child soldier phenomenon in the Philippines. Specifically, it aims to come up with a picture of the child soldier phenomenon in the country, analyze the various factors or conditions contributory to the participation of children in armed conflict, explore the issues and challenges the child soldier phenomenon poses in social work practice and draw lessons or insights that can contribute to the improvement of current social work practice. This qualitative study used personal interview and instrumental case study methods in data gathering. Selected regional social workers of the government's welfare department, who have handled cases of children involved in armed conflict, served as the main source of information. They were selected through purposive sampling. Likewise, instrumental case study method was used to strengthen and enrich the data gathered using 31 selected case files of child soldiers. The information was analyzed using an ecological and structural framework. This research has shown that the child soldier phenomenon in the country is multidimensional and connected with various factors internal and external to the child. The existence of the phenomenon could not be attributed solely to a single factor but rather to combination of factors in the child's environment, which serve as a cumulative force that pushes the child to participate in the armed group. This study put forth the need for a multifaceted approach in social work practice with child soldier where all systems - micro, meso, exo, macro - in the child's immediate and distant environment are considered in the entire helping process. Likewise, it stressed the need for social work actions that provides not only immediate relief to individual child and her/his family, but also longer-term solutions that targets oppressive and unjust institutional and structural order in the society. It affirmed the importance of transformative social work practice where interventions go beyond mere palliative care and the importance of reflective practice where reflection-in-action is integral to the performance of social work profession.

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  • Gene expression in the precocious germination of late maturation Phaseolus vulgaris L. seeds: a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology at Massey University

    Smith, Howard Russell

    Thesis
    Massey University

    Ethylene induces precocious germination in late maturation embryos (32-40 days after anthesis) of Phaseolus vulgaris L. cv. Seminole, thus overriding the endogenous controls which normally maintain quiescence. The possibility that ethylene exerts its effects at the gene expression level was investigated by in vitro translation of RNA extracted from embryo axis tissue of seeds induced to germinate precociously by incubation with ethylene. 35 S-labelled products so produced were analyzed by electrophoresis, fluorography, and scanning densitometry. Results were compared with normally germinating seeds and with embryos incubated in the absence of ethylene. Ethylene was found to induce a qualitative and quantitative change in gene expression in late maturation embryos detectable within 6 hours of ethylene exposure. Two products (37-38kD and 27kD) were up-regulated within 24 hours in both ethylene-induced precocious germination and normal germination. Four products (71kD, 67-68kD, 65-66kD, and 41-42kD) which appeared in normal germination were evidently not required for ethylene-induced precocious germination. In contrast with the findings of Misra & Bewley (1985;1986) for maize(Zea mays L.) no products could be identified as being unique to the developmental phase, however two products (38-39kD and 28kD) were strongly present in development but disappeared shortly after germination. A product of 22-23kD was apparently unique to the ethylene-induced precocious germination treatment and may represent a gene regulated by ethylene. This product was not seen until 24 hours after ethylene introduction. An attempt was made using SDS-PAGE to identify the major storage proteins of P.vulgaris to use as markers of the developmental phase, however this was only partially successful. Suggestions are made as to approaches and methods for future research.

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  • Improved mass cultivation of the marine diatom Chaetoceros calcitrans for shellfish hatcheries : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Biotechnology at Massey University, Palmerston North, New Zealand

    Tannock, Simon John Charles

    Thesis
    Massey University

    A medium for the optimal growth of Chaetoceros calcitrans in batch and continuous culture systems was developed. A method was developed for continuous culture of C. calcitrans that was free from detrimental infection by bacteria. The concentration of tested nutrients in the developed medium were sodium nitrate, 160 mg/L; sodium dihydrogen orthophosphate, 40 mg/L; and the molar Si:N ratio was 0.25 (99.9 mg/L sodium metasilicate). Isolated bacterial strains were shown to be detrimental to the growth of C. calcitrans in batch and continuous culture. Electrolytically treated water was suitable for the growth of C. calcitrans, but a subsequent flourish of bacterial growth at the late exponential phase reduced the quality of the algal cells and made the culture unsuitable for feeding to shellfish larvae. Heat treated water (95°C for ten and a half minutes) gave stable growth for the continuous culture of C. calcitrans in 38 L plastic bioreactor bags for at least 38 days. The superficial gas velocity in the culture bags was 0.09 L/min. Higher superficial gas velocities (e.g. 0.40 L/min were detrimental to C. calcitrans.

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