9,792 results for Massey Research Online

  • Systemic Mycobacterium avium subspecies paratuberculosis infection in sheep : a thesis presented in the fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Palmerston North, New Zealand

    Smith

    Thesis
    Massey University

    Publications removed from thesis due to copyright reasons: Smith, S. L., West, D. M., Wilson, P. R., de Lisle, G. W., Collett, M. G., Heuer, C., & Chambers, J. P. (2011). Detection of Mycobacterium avium subsp. paratuberculosis in skeletal muscle and blood of ewes from a sheep farm in New Zealand. New Zealand Veterinary Journal, 59(5), 240-243. doi:10.1080/00480169.2011.596257. Smith, S. L., West, D. M., Wilson, P. R., de Lisle, G. W., Collett, M. G., Heuer, C., & Chambers, J. P. (2013). The prevalence of disseminated Mycobacterium avium subsp. paratuberculosis infection in tissues of healthy ewes from a New Zealand farm with Johne's disease present. New Zealand Veterinary Journal, 61(1), 41-44. doi:10.1080/00480169.2012.704627. Smith, S. L., Wilson, P. R., Collett, M. G., Heuer, C., West, D. M., Stevenson, M., & Chambers, J. P. (2014). Liver biopsy histopathology for diagnosis of Johne's disease in sheep. Veterinary Pathology, 51(5), 915-918. doi:10.1177/0300985813516644. Smith, S. L., Singh, P., Harding, D., Lun, D., & Chambers, J. P. (2016). Thalidomide pharmacokinetics in sheep. New Zealand Veterinary Journal, 64(4), 238-242. doi: 10.1080/00480169.2015.1130663

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  • Development of a mathematical model for 'Hayward' kiwifruit softening in the supply chain : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, New Zealand

    Zhao, Junyu Matthew

    Thesis
    Massey University

    Fruit loss is a major concern to the kiwifruit industry as it incurs a high cost to monitor and remove over soft or rotten fruit to meet export standards. Kiwifruit is exposed to various temperature scenarios due to different packhouse cooling practices, and temperature control is difficult to maintain throughout the supply chain. Fruit pallet temperatures are wirelessly monitored in the supply chain. This time temperature data provides valuable rich information which could be used to predict kiwifruit quality. In the laboratory, green ‘Hayward’ kiwifruit were exposed to industry coolchain scenarios to investigate their influence on fruit firmness in subsequent storage. Cooling rate and storage temperature were identified to affect fruit firmness and chilling injury development significantly, where accelerated softening and increased chilling injury development was observed in late storage (> 100 d) when fruit were cooled directly to 0 °C. However, when fast cooled fruit were stored at 2 °C instead of 0 °C, low incidence of chilling injury was observed. The influence of cooling rate and storage temperature on kiwifruit quality suggests that industry should focus on the management practices adopted by packhouses in order to maintain acceptable quality after long term storage. A proportion of the firmness data results were used to develop a mechanistic style mathematical model of kiwifruit softening. Kiwifruit softening was mathematically described based on the correlation with starch degradation, breakdown of cell wall structure, and a description of the incidence of chilling injury development during storage. The model inputs consist of solely commonly collected at-harvest attributes: firmness, dry matter and soluble solids content and time-temperature data. Applying at-harvest attributes as model inputs enabled a capability to predict different softening curves as influenced by fruit maturity, and grower line differences. The developed model demonstrated promising softening prediction with mean absolute errors (MAE) between 0.8 to 2.1 N when fruit were exposed to fluctuating temperatures and cooling profiles. A logistic model was used to estimate the proportion of chilling injured fruit. Based on the given time temperature information, the logistic model was able to predict the proportion of chilling injured fruit reasonably well (R2 = 0.735). This chilling injury prediction was subsequently used to adjust the softening prediction during the late storage period (>100 d). Model validation was performed using the remaining data, identifying a lack of fit in both the rapid (MAE of 20.8 N) and gradual (MAE of 8.0 N) softening phase. The lack of fit in the rapid softening phase is proposed to be explained by the presence of an initial lag phase in softening which the developed model is unable to predict. The magnitude of firmness associated with starch content and cell wall integrity heavily influenced the lack of fit in the gradual softening phase. Fixing the initial amount of firmness associated to cell wall integrity to be constant for all maturities and grower lines improved the softening prediction. Overall, this thesis contributes to the challenge of predictively modelling kiwifruit quality in the supply chain. However, there are still many opportunities for improvement including introducing the influence of: variation within the same batch; fruit maturity on chilling injury development; ethylene in the environment; pre-harvest management practices and extending the model to have more focus on high temperature conditions such as those experienced in the marketplace. Conducting studies on: the effect of curing on kiwifruit; using non-destructive techniques to provide information to help define model parameters for prediction; effect of high temperature exposure on kiwifruit softening are possible opportunities that may contribute to enable better prediction of kiwifruit quality in the supply chain in the future.

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  • Curiosity and self-concept of school adjustment : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Education at Massey University

    Doyle, Michael Dennis

    Thesis
    Massey University

    This study, as a piece of descriptive research, is an extension of a similar one done by Maw and Maw (1970) concerning the relationship between curiosity and the self-concept. Whereas they hypothesised that children high in curiosity are also those who have successfully interacted with their environments, the general hypothesis for this study was that children who have positive self-concepts of themselves in the school environment will also be ones who exhibit curiosity in that situation. This hypothesis was formulated as a consequence of the writer's adherence to a theory of active intelligence, and view of self-concept as a highly task-specific construct. Measures of curiosity, global self-concept, and self-concept of school adjustment were taken. In general terms curiosity was defined as a preferred cognitive strategy which is utilized to cope with challenging stimuli and manifested in the way in which the individual is predisposed to achieve and resolve conceptual conflicts. Global self-concept was defined as an individual's perception of his innate capacity to cope effectively with his environment. Similarly self-concept of school adjustment was defined as a student's perception of his innate capacity to cope effectively in the specific environment of the classroom. Each of these three variables was operationally defined in terms of the instruments used to measure them. Where possible, the same instruments as used by Maw and Maw in their study were used in this research. No new instruments were constructed for this study. Measures of curiosity were taken from Maw and Maw: (1) Teacher's Rating Scale of Curiosity, (2) Self-appraisal of curiosity, (3) The Which to Discuss Test. Measures of global self-concept were obtained from the following instruments: (1) Parts of the California Test of Personality (C.T.P.), (2) Parts of the Children's Personality Questionnaire (C.P.Q.). A measure of self-concept of school adjustment was obtained from subjects recorded responses to factor 2 E : School Relations, of the California Test of Personality (C.T.P.) and from the tester's recorded observation on the Bristol Social Adjustment Scale: factor U (Unforthcomingess). P.A.T. results for reading comprehension and maths were taken from school records. The subjects were 20 children from the senior room of a local two-teacher school. There were ten boys and ten girls. It is felt that they are representative of New Zealand rural children. Administration and scoring of the tests was done by the writer, who at the time of testing was also the children's teacher. The results of the study did not support the general hypothesis, and only partly supported Maw and Maw's (1970) findings. However, some relationship between the variables curiosity, self-concept and self-concept of school adjustment was shown to exist. Also a highly significant relationship was recorded between curiosity and school achievement. A lack of significant relationship recorded between the teacher's rating of curiosity and the C.T.P. measure of Total Personal Adjustment was taken to suggest that either the tests in fact measure different things than curiosity and personal adjustment or, that there was error in administration or scoring of at least one of the tests. Both of these factors, as measured on the same tests, correlated significantly in the Maw and Maw study. Unfortunately the lack of correlation mentioned above also affected the recorded relationship between the teacher's rating and the school adjustment measure from the C.T.P. One implication of these results is that curiosity as a task-specific concept is merely one aspect of cognition. The possibility of marker bias was discussed, but if this can be discounted then the significant correlations which existed between curiosity, school adjustment and school performance can all be taken as evidence that curiosity is in fact connected with intelligence. Consequently, it would seem that better school adjustment is more readily found in higher achievers.

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  • Design and development of a hybrid flexible manufacturing system : a thesis presented in fulfilment of the requirements for the degree of Master of Technology at Massey University

    Jolly, Matthew J

    Thesis
    Massey University

    Volumes 1 and 2 merged.

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  • Electromagnetic propagation through non-dissipative and dissipative barriers : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Physics at Massey University, Palmerston North, New Zealand

    Shalav, Avi

    Thesis
    Massey University

    COMPUTER DISK UNREADABLE.

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  • Design and development of a competitive wire splicing system for the automotive wire harness industry : a thesis presented in partial fulfilment of the requirements for the Master of Technology in Manufacturing and Industrial Technology at Massey University, Palmerston North, New Zealand

    Potharaju, Venkata Subbarao

    Thesis
    Massey University

    The work presented in this thesis is aimed at developing a very comprehensive system of manufacturing wire splices for automobile wire harnesses. Ultrasonic welding is increasingly being used in various industrial applications. Lack of a scientific data-base of its properties when applied to wire splicing is a major reason for lack of proper usage by the wiring harness industry and its subsequent acceptance by the end user. This thesis presents various experiments conducted to develop tensile strengths and electrical resistances of various types of ultrasonically welded wire splices. Crimping technology was evaluated for its mechanical strengths and electrical properties by conducting various experiments to make it possible for the industry to compare it with other alternative splicing technologies. The results are then compared with ultrasonic welding. The next stage of this thesis discusses the economic feasibility of ultrasonic wire splicing. In order to find the number of ultrasonic welding machines required to meet a particular level of demand, which is a prerequisite for establishing the economic feasibility, a virtual model of the process and the manufacturing cell has been prepared and this model was used to study the dynamics of demand and the number of required machines. Simulation in manufacturing-problem-solving is being used very widely by researchers. Proper understanding and visualisation of the future of the factory and understanding and answering various questions related to the adoption of new technology, is another major reason why companies shy away from adopting ultrasonic welding systems. An advanced simulation tool namely QUEST was used to model the wire splice manufacturing cell of Alcatel and simulation studies were conducted to foresee how the production dynamics would be if ultrasonic welding machines were incorporated in place of crimping machines and various what if scenarios were developed and some vital production related questions were answered. Material handling is a major bottleneck in any wiring harness manufacturing environment. Some conceptual designs are presented on automating the task of feeding wires to ultrasonic welding machines and transferring the wire assemblies from welding stations to different work stations, currently being done manually. A wire palletising system was designed to improve the productivity. This thesis concludes that ultrasonic welding could be very effectively used for wire splicing and could be safely used in the manufacture of wiring harnesses for the automobile industry.

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  • Dental fluorosis caused by volcanic degassing in West Ambrym, Vanuatu : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Earth Science at Massey University, Palmerston North, New Zealand

    Crimp, Rachel Janice

    Thesis
    Massey University

    Fluorosis, both dental and skeletal, is a disease afflicting millions of people worldwide and is caused primarily by the ingestion of fluoride-rich drinking water. Usually, this is groundwater that has leached fluoride from underlying rock deposits. In West Ambrym. Vanuatu, however, the indigenous people live in close proximity to a degassing volcano and harvest rainwater for their potable water needs. The current project investigated two hypotheses; firstly, that dental fluorosis existed in West Ambrym and secondly, that it was caused by the ingestion of rainwater contaminated by the degassing volcanic plume. A dental survey was undertaken of children ayed 6 to 18 years using the Dean's Index of Fluorosis. A total of 835 children participated; 253 of whom came from the target area of West Ambrym. For comparative analysis and a more regional perspective, the remaining 582 surveyed were from other nearby locations. Drinking water, non-drinking water and food samples were collected for fluoride analyses. Dental fluorosis prevalence was found to be 96% in West Ambrym, 85% in Malakula, 71% in North Ambrym, 61% in Southeast Ambrym, 36% in Tongoa, 43% in an 'incidental islands' group, and 100% on Tanna. Drinking water samples from West Ambrym ranged from 0.7 to 9.5 ppm F (average 4.2 ppm F). Groundwater sources ranged from 1.8 to 2.8 ppm F (average 2.2 ppm F). Of the 158 drinking water samples, 99% were over the World Health Organisation recommended concentration of 1.0 ppm F. It was found that pH was not a suitable proxy for fluoride concentration. That painted and/or rusted corrugated iron roofing may play a role in lowering fluoride concentration of stored rainwater was a tentative finding. Coconut juice was a rich source of fluoride. Food samples ranged from <6 ppm F to over 100 ppm F. The current research has shown that the semi-continuously degassing of Ambrym volcano is introducing significant levels of fluoride into the drinking water of the local Ni-vanuatu. This geo-meteorological process has resulted in the development of widespread dental fluorosis in West Ambrym. The pathway of fluoride-enriched rainwater identified in this study has not previously been recognised in the aetiology of fluorosis. Defluoridation, or accessing an alternative water source, accompanied by modified rainwater harvesting practices, are means by which the prevalence of the disease can be markedly reduced.

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  • Comprehensive investigation of mechanical properties of fused deposition modelling : a dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering at Massey University, Albany, New Zealand

    Ferreira, Arno

    Conference item
    Massey University

    Fused depositing modelling (FDM) is a layer wise manufacturing method whereby parts are printed from the bottom up through the extrusion and deposition of a filament onto a print base. Various test methods exist for the determination of part mechanical properties. These include tensile, flexural, and impact testing and are conducted using a variety of standards including those of ASTM and ISO. Many researchers have investigated the effects of factors such as road width, raster orientation, layer height, and air gap on the mechanical properties of FDM parts. However, there are many unexplored factors that also impact on the properties of printed parts. For example, the printers used in characterisation studies are mostly commercially available or consumer market printers which allow only limited control over the print parameters and print with a limited set of materials. Similarly, the life of the printer can also affect the print quality but this has not been studied before. Control over machines could be achieved by purchasing additional print profiles from the manufacturers or by open-sourcing legacy hardware through retrofitment with new electronics and software. The latter option is more economically viable as there are a large number of decommissioned legacy machines that have superior hardware cheaply/freely available. A retrofitted commercial 3D printer would allow control over print parameters and printing with materials outside the ones sold by the manufacturers. This can open new avenues to study the properties of the printed parts. In this work, a Stratasys Vantage X 3D printer has been retrofitted and made open-source through a combination of hardware, software, and firmware modifications. These modifications result in complete control by the user over all print variables along with the ability to use any feedstock including custom made feed stocks and ones that are locked by the manufacturer. The printing accuracy of the machine is evaluated by optical imaging of the printed samples and destructive testing in accordance with the ASTM D638 standard. . To study the effect of the machine’s life on the properties, a longitudinal study is designed in which two groups of parts (with 0° and 90° orientations) are printed at two different times during the course of this research. The temporal spacing between the parts is eighteen months. The parts are designed according to ASTM D638 standard and printed on identical printers using the same parameters on both occasions. The parts are subjected to tensile testing for the mechanical characterization while scanning electron microscopy (SEM) is used for the examination of the sample’s fracture and topographical surfaces. A difference is discovered between the Young’s moduli of old and new groups. The orthotropic nature of FDM parts becomes prevalent in the strain responses of samples with 0° samples experiencing the largest strain. Distinct differences exist between the diffusion levels of the chronological sample groups, with the original batch exhibiting greater diffusion resulting in almost indistinguishable layers and higher tensile strengths. Individual layers are easily observed in the newer sample groups. Topographical analysis of samples shows up to 0.1mm difference between the road widths with the older samples roads being the narrowest. Results from this research show that the age of the printer affects the mechanical properties of the parts with the older parts exhibiting greater strength compared to their new counterparts even though both were printer under identical conditions. Therefore, a significant difference exists between temporally spaced FDM parts. To conclude, this research has successfully retrofitted an old FDM system which is capable of printing various materials through a choice of user parameters. The longitudinal study conducted to study the effect of the machine age on the printed parts purports that as the printing machines get older their print quality deteriorates and this factor should be considered by designers when designing parts for functional purposes.

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  • The Christchurch green belt-- reality or just a name? : a thesis presented in partial fulfilment of the requirements for the degree of Master of Resource Planning, Massey University

    Chesterman, Rhys

    Thesis
    Massey University

    The Green belt concept grew out of the English Garden City movement of the nineteenth century. Although the thoughts and theory were widespread throughout the first half of the twentieth century, it was not until 1959 that green belt policy became legislative reality. The initial result was the London Green Belt: other green belts around major cities followed The predominant objective of the green belt at that time was to restrict urban sprawl, and the concept was initially well supported by citizens, planners and the Biitish government. The British government attaches great importance to green belts, which have been an essential element of planning policy for some four decades. The purposes of green belt policy and the related development control policies set out in 1955 remain valid today with remarkably little alteration. This sophisticated and comprehensive approach provided a model that many other cities around the world have since followed. Christchurch for example inherited its planning legacy from the British experience. Although first defined in 1954 as a 'non-settlement area', (meaning the same thing) it was not until the 1980's that the term 'green belt' was formally used in New Zealand statutory planning documents Since then (particularly in the later 1990's) there has been speculation that the green belt philosophy has begun to fade The green belt containment policy was designed to thwart urban spread but has instead led to piecemeal development. Essentially, this has led to a rethink of the green belt. There is some speculation that the codification of green belt policy that originated in 1955 in London is not applicable to the city of Christchurch. Furthermore, new legislation by the way of the Resource Management Act has altered the philosophies of land-use planning and encouraged a new way of thinking. This new thinking is based on sustainable management objectives and has been responsible for much of the green belt's recent decline. No longer can a single land-use tool restrict development in such a large area without considering other potential uses, while simultaneously juggling it with the sustainable management principle. Accordingly it has raised questions as to whether the Christchurch green belt concept is worth keeping, and if not, what other means are available to help continue to promote the green belt objectives that were first introduced many decades ago.

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  • The effects of traumatic brain injury on complex figure test performance : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University

    Bowie, Jonathan M. H

    Thesis
    Massey University

    Patients with Traumatic Brain Injury (TBI) have performed below norms on the Complex Figure Test (CFT) and this has been attributed to lack of organization (Binder, 1982). The present study compared 105 TBI subjects with 59 Controls in terms of accuracy and organization to examine whether lower TBI subject organization was associated with subsequent lower accuracy. Results showed that TBI subjects scored lower accuracy than controls on copy, recall and delay trials but did not score lower for organization (as measured by Hamby, Wilkins & Barry, 1993). Both groups were consistent in organizational approach across the three CFT trials, and copy organization scores of both groups were positively correlated with accuracy scores on recall and delay trials. This suggests that TBI subjects do have a problem with the CFT, but it cannot be linked to copy organization on the basis of evidence from the present study. The unexpected results were attributed to methodological problems involving the population samples and the organization measure.

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  • Decentralization, identity construction, and conflict : education under Aceh's special autonomy : a dissertation presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Development Studies, Massey University, Palmerston North, New Zealand

    Fitriah, Amaliah

    Thesis
    Massey University

    This study contributes to the existing literature on decentralization by exploring the relationship between decentralization, identity construction and conflict in the context of decentralization reform in Indonesia. Using the concept of bottom-up autonomy as its theoretical lens, this study explores the impact of political decentralization on the autonomy of Aceh and examines the notion that autonomy can contribute to peaceful management of intra-state conflict. The study involves research into education stakeholders in the two districts of Aceh and uses the qualitative methods of pairwise ranking, semi-structured interviews, observation, and document analysis. More specifically, the impact of decentralization on the autonomy of Aceh is investigated through perceived changes in three areas of education: the curriculum, the structure, and the financing of education. The results demonstrate that the autonomy agreed between Aceh and the Indonesian government has contributed to extensive bottom-up autonomy for Aceh by accommodating the distinct identity of the Acehnese and by providing a political framework for local empowerment. Through providing frameworks for the accommodation of local identity and for local empowerment, the form of bottom-up autonomy resulting from political decentralization has offered negotiated avenues for managing intra-state conflict peacefully. These frameworks have hopefully created common ground for both parties to sustain peace. However, this study also revealed that there is potential for internal discontent within Aceh society as a result of perceived unequal access to resources. This study does not, therefore, emphatically conclude that political decentralization necessarily reduces conflict. Instead, this research suggests that political decentralization which results in extensive bottom-up autonomy may be a tool for promoting a more peaceful management of conflict between regions and the central state than would otherwise be possible.

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  • Characterisation & process control of pumping systems in the dairy industry : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Technology at Massey University

    Dorsey, Mark Richard

    Thesis
    Massey University

    CD held with Reference copy

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  • Effect of transglutaminase on milk proteins : a thesis presented in partial fulfilment of the requirements for the degree of Master in Technology at Massey University, New Zealand

    Trejo Araya, Ximenita Isabelle

    Thesis
    Massey University

    In this study transglutaminase was used to achieve ε-γ-(glutamyl) lysine cross-linking of milk proteins, in Trim™ and Full Fat milks, the same milks with a variety of added protein concentrates, and finally in yogurt and Petite Suisse acid gel systems. The effects of a preheat treatment, enzyme incubation temperature, enzyme inactivation after the enzyme incubation period and homogenization on the cross-linking of the three major casein and two whey proteins were also studied. The degree of cross-linking was established by the use of SDS PAGE gel electrophoresis. The results indicated that cross-linking of the major casein and whey proteins was maximized if the milk was preheated for 10 minutes at 90°C and then cooled before addition of the transglutaminase. However, the preheat treatment was not always advantageous in Trim™ milk systems, but was essential for Full Fat milk systems. Maximal cross-linking of milk proteins occurred if the enzyme/milk system was incubated at 37°C for two hours rather than at 55°C for the same period. The extent of cross-linking increased in an almost linear fashion with increasing transglutainase concentration in most milk systems, with maximal cross-linking occurring when the enzyme concentration was 100 U/mL. Studies on one milk system showed that whey loss and gel strength deteriorated if more than 100 U/mL of enzyme was used. The study demonstrated that homogenization was an essential step for protein cross-linking if the system contained any fat. Casein and whey protein transglutaminase mediated cross-linking was maximized in Full Fat milk systems if the milk was homogenized before transglutaminase was added. Maximal cross-linking, particularly of whey proteins, occurred in Full Fat milk systems if the milk was preheated for 10 minutes at 90°C, cooled to 60°C and then homogenized at 50/150, cooled further to 37°C and then incubated with 100 U/mL of enzyme for two hours. Addition of sodium caseinate or milk protein isolate to Trim™ and Full Fat milk systems was shown to significantly improve protein cross-linkage by up to 50% for β-casein and whey protein respectively. Transglutaminase addition to milk systems containing the previously mentioned protein concentrates further enhanced cross-linking compared to the non-enzyme controls, particularly when the enzyme concentration was 100 U/mL Addition of transglutaminase to acid milk gels dramatically improved the whey holding and gel properties of the products, particularly when the enzyme concentration was 100 U/mL. The reduction in whey loss was proportional to transglutaminase concentration up to 100 U/mL. A 100% reduction in whey syneresis and a 10g F improvement in gel strength improvement were obtained when 0.5 % sodium caseinate and 100 U/mL of transglutaminase were added to a gel milk system compared to a control sample with no enzyme. The physical properties of the milk acid gels were further improved if the transglutaminase in the acid gel systems was not inactivated prior to the addition of the enzyme. The addition of milk protein concentrates such as sodium caseinate and total milk proteinate were shown to have dramatic effects on the whey holding and gel properties of acid gels. Moreover, the properties showed little reduction over a two week storage period compared to yogurt with no added protein. The addition of transglutaminase at a concentration of 100 U/mL further enhanced the above physical characteristics of the acid milk gels. Variations in cross-linking within systems containing either sodium caseinate, milk protein concentrate and milk protein isolate were observed. These variations need to be examined in further work. The addition of NaCNTMP further enhanced the gel and whey-holding properties compared to systems containing either sodium caseinate or total milk proteinate. The final study was conducted on Petite Suisse, a high fat acid milk gel, and here the addition of transglutaminase at 100 U/mL dramatically improved the gel strength of the system by 500% compared to the control. Finally, this research confirmed that transglutaminase effectively cross-linked milk proteins, and in particular β- and κ-casein and β-lactuglobulin. Transglutaminase addition to milk and acid milk systems clearly improved some of the physical properties of the systems. However, much work is needed before it could be recommended for use by industry. The effect of adding transglutaminase to acid milk gels and milk systems should be evaluated by consumer panels to ensure that the sensory properties of these systems have in no way been compromised. Furthermore the economic costs of adding transglutaminase should be determined to ensure that the process would not be uneconomic. If the above evaluations prove to be beneficial then the process could be investigated and further studies carried out to see whether improvements could result by addition of transglutaminase to such milk products as yogurts, desserts, cheese etc, and to create new products with different textural and water holding characteristics. Further work is needed on a scientific front to assess the effects of transglutainase and added proteins on the structure of milk gels and the precise mechanism of filament formation in these gels. Some questions were also raised concerning the exact mechanism that was responsible for removal of monomeric forms of whey protein in the various milk systems evaluated in this study, and these should be determined by further research work.

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  • The effect of pre-information on clinical inference and nursing actions : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University

    McIntosh, Muriel Joan

    Thesis
    Massey University

    A study to examine the effects of pre-information (what a nurse learns about a patient before they meet) on clinical inference and nursing actions, in a simulated nurse-patient situation. It was hypothesised that the nature of the pre-information will influence the way the patient is perceived, and the resulting nursing actions. The research was conducted in an obstetrical setting. There were 55 subjects within three groups. Two groups comprised student midwives, and the third group was of second year comprehensive nursing students near the completion of clinical experience in maternal and child health nursing. A five minute videotape sequence of a role-played post-natal patient was made for use in the research. All subjects were given the same initial pre-information, viewed the videotape and gave written descriptions of what they saw on the videotape and their response (as the nurse in the situation). This data provided a base-line for each subject. Subjects were then given additional pre-information concerning the patient's physical condition, her baby's condition, or formed part of the control group (receiving no additional pre-information). The procedure was repeated. These responses were then compared with the base-line for each subject. Responses were coded by means of content analysis. Group data was analysed using a multivariate one way analysis of variance graphical display. The results indicated support of the hypothesis that the nature of the pre-information does influence the way in which a nurse perceives a patient, and resulting nursing actions. Implications of these findings for nursing are discussed.

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  • Effect of homogenisation on milk fouling in a tubular heat exchanger : a thesis presented in partial fulfilment for the requirements for the degree of Master of Food Engineering, Massey University, Palmerston North, New Zealand

    Martinez-Sanchez, Monica

    Thesis
    Massey University

    Fouling of equipment surfaces in milk processing has been a costly problem for many years. In spite of an increasing body of knowledge of the fouling mechanism, the problem is not fully understood yet. Recent investigations suggest that the role of fat in whole milk fouling seems to be very important. The state and form of the fat globules, processing conditions as well as the orientation of heating surfaces may affect the fouling mechanism. Homogenisation of milk is known to cause disruption of fat globules and prevent creaming. The present work aimed to investigate the effect of homogenisation on the rate of fouling, composition and structure of fouling layers. Homogenised and un-homogenised milk were used as test fluids. Milk was heated from 4°C to 60°C in a plate heat exchanger then to 70°C and 80°C in a double pipe heat exchanger consisted of a horizontal and a vertical tube. The fouling rate in the double pipe heat exchanger was calculated and expressed as the rate of increase of the overall resistance to heat transfer, normalised using the initial heat transfer coefficient at the beginning of the run. Composition analysis of fouling layers was carried out using standard methods of moisture, ash, fat and protein tests. Resistance to deformation analysis was performed using texture tests; coverage measurement was determined by digital image analysis. Within the experimental conditions used in this work, the effect of homogenisation on the fouling rate could not be ascertained conclusively because of large variations in the values obtained but it had a significant effect in the composition of fouling layers. In all experimental runs, the amount of fat in the fouling layer was higher for un-homogenised milk compared to homogenised milk. In fact, the fat contents of fouling layers were found to be very high (between 30%-60% on a dry weight basis), which agrees with observations of other researches in New Zealand. The coverage and thickness of fouling layers were more influenced by the orientation of heated surfaces than by homogenisation. The strength of fouling layers is affected by their thickness, which decreases with increasing milk temperature.

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  • Characterisation of a putative dothistromin biosynthetic cluster : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Molecular Biology at Massey University, Palmerston North, New Zealand

    Laarakkers, Seth

    Thesis
    Massey University

    The fungus Dothistroma pini is a key pathogen in New Zealand (and international) softwood plantations, most notably P. radiata. The mycotoxin dothistromin produced by this saprophytic fungus is believed to play a major role in its pathogenesis. Dothistromin shares functional groups and pathway intermediates with those of sterigmatocystin and aflatoxin, secondary metabolites of Aspergillus sp. As the sterigmatocystin and aflatoxin biosynthetic pathways are characterised this provided us with a model pathway and potential probes for the isolation of dothistromin genes. The verl gene is critical to the completion of aflatoxin biosynthesis in Aspergillus sp. as its disruption prevented the synthesis of aflatoxin. Assuming similar enzymes act in the dothistromin biosynthetic pathway a probe for ver1 was obtained and used to probe a D. pini genomic library. This led to the isolation of two lambda clones named λCGV1 and λCGV2 (Gillman 1996). A second library screen was completed using an aflatoxin polyketide synthase (PKS) probe and led to the isolation of the lambda clone λBMKSA (Morgan 1997). The λCGV1 clone has been studied in detail and shown to contain a gene similar to aflatoxin ver1 (named dkr1) and other potential dothistromin biosynthetic genes (Monahan 1998). This study looks in greater detail at the lambda clones λCGV2 and λBMKSA and determines whether they contain putative dothistromin biosynthetic genes and are part of the anticipated gene cluster. In this project the lambda clone λCGV2 was partially characterised which revealed that the other potential ver gene showed a greater similarity to the melanin biosynthetic gene phn than to the aflatoxin gene ver-1. This implied that the clone was unlikely to contain dothistromin biosynthetic genes so no further sequence was generated. However, a partial restriction map was constructed. The other lambda clone, λBMKSA was then further characterised. Double stranded sequence of the putative pks gene region was completed. The remainder of the lambda clone was subcloned and exploratory sequence revealed a gene with high similarity to stcW. The next stage was to determine how the three lambda clones were related. This was approached by probing genomic Southern blots with the ends of the lambda clones to determine the presence of commonly hybridised fragments. The presence of common fragments suggests that the three clones are very close together in the genome, although the evidence which links λCGV2 and λBMKSA is stronger than the evidence that links λCGV2 and λCGV1. This is the first evidence that the three lambda clones isolated using aflatoxin probes are close together in the genome of D. pini. The genes present on these lambda clones show a high degree of similarity to their aflatoxin counterparts and could potentially contain a dothistriomin biosynthetic cluster.

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  • Effect of cultivar, time of sowing and fungicide application on seed yield of cocksfoot (Dactylis glomerata L) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Plant Science in Seed Technology at Massey University, Palmerston North, New Zealand

    Wilson, Sonya M

    Thesis
    Massey University

    Three New Zealand (Grasslands Wana, Grasslands Kara, Grasslands Tekapo) and two Japanese (Akimidori, Makibamidori) cocksfoot cultivars were sown in spring (23 September 1991) and again the following autumn (6 April 1992) at AgResearch Grassland's Aorangi Research Farm in the Manawatu. Seed was sown at 3 kg/ha with a 30 cm row spacing. Plot size was 1.2 x 3.0 m2, with each plot containing 4 rows. A randomised block design was utilised with 8 replicates of each cultivar for each sowing time. For each cultivar and sowing time four of the eight replicates were sprayed with propiconazole (125 g a.i/ha) on 17 November 1992 and 8 December 1992. Spring sowings outyielded autumn sowings by 150 to 482 kg/ha depending on cultivar The ability of the spring sown cultivars to outproduce autumn sown cultivars was due largely to their ability to produce a greater number of fertile tillers. Autumn sown cultivars failed to produce a large number of fertile tillers which lead to a reduced potential seed yield. This was further exaserbated by the fact that the floret site utilisation (FSU) of the autumn sown cultivars was lower than that of the spring sown cultivars. Cultivar Wana was the only cultivar able to produce a reasonable number of fertile tillers following autumn sowing. It was also able to double the number of florets/tiller compared to that of spring sown cv Wana, thus allowing it to produce a reasonable seed yield. Cultivar Wana produced 557 kg seed/ha from the autumn sowing, and cv. Tekapo 244 kg seed/ha, but yields for the other three cultivars were less than 100 kg/ha following autumn sowing. Spring sowing produced pure seed yields of 707, 566, 593, 383 and 307 kg/ha for cv. Wana, Tekapo, Kara, Akimidori and Makibamidori respectively. Apart from cv Wana, fungicide application to autumn sown plots did not significantly increase seed yield, and similarly no differences were recorded for spring sown cv Akimidori and Makibamidori. However fungicide application significantly increased seed yieid in cv Wana, Kara and Tekapo, the increases being 521 (+ 74%), 119 (+ 21%) and 564 (+ 95%) kg/ha respectively, even though the incidences of fungal pathogens was less than 1%. These seed yield increases were due to an increase in the green area of the leaves and stem. In cv Wana and Tekapo there was also a significant increase in FSU due to the application of fungicide. Following harvest stubble was removed and the area retained for another year and subsequent harvest. As the effects of time of sowing were considered no longer significant, the trial was run as one block of 80 plots, thus giving 16 replicates of each cultivar. For each cultivar, four replicates received one of four different fungicide (188 g ai/ha of terbuconazole) treatments; a nil application, one application at approximately 10% ear emergence, one application at approximately 10% car emergence followed by another at early anthesis and one application at early anthesis followed by one post anthesis (10 days after full anthesis). In the absence of fungicide pure seed yields produced were 1133, 1208, 915, 556 and 671 kg/ha for cv. Wana, Kara, Tekapo, Makibamidori and Akimidori respectively. Although once again the incidence of fungal pathogens was less than 1%, fungicide increased the seed yield of all cultivars. The best results came from two applications of fungicide, one at ear emergence and one at anthesis. The exception to this was for cv Tekapo which gained the greatest increase from one application at ear emergence. These treatments increased the pure seed yield by 29%, 15%, 23%, 43% and 19% for cv Wana, Kara, Tekapo, Makibamidori and Akimidori respectively. Different cultivars reacted differently to the application of fungicide, with fungicide significantly increasing the thousand seed weight of cv Kara. Tekapo Akimidori and Makibamidori, although it had no such effect on cv Wana. Fungicide application increased the FSU of cv Wana and Tekapo but did not significantly affect cv Akimidori, Makibamidori and Kara. Cultivars Wana and Makibamidori showed a significant association between green area and seed yield, but these relationships were not significant for the other three cutivars. There was a significant association between FSU and seed yield after fungicide application for all the cultivars except cv Kara. The most cost effect return for the application of fungicide was that of a single application at ear emergence. Keywords: Cocksfoot, Dactylis glomerata, rust, eyespot, propiconazole, terbuconazole, fungicide, sowing date, cultivar.

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  • Citric acid production by immobilized cells of the yeast Candida guilliermondii : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Biotechnology and Bioprocess Engineering at Massey University

    Tisnadjaja, Djadjat

    Thesis
    Massey University

    The feasibility of using cells of Candida guilliermondii immobilized onto sawdust particles for production of citric acid was investigated. C. guilliermondii IMK1 from a stock culture (Department of Process and Environmental Technology, Massey University, Palmerston North, New Zealand) was reisolated for further study including strain improvement work by induced mutation using UV light. A mutant strain DT2 was isolated which produced a citric acid concentration of 9.2 g/l (yield 25 % (w/w)) in shake flask culture, using a defined medium containing 36 (g/l) glucose, compared with 4.9 (g/l) citric acid produced (yield 14 % (w/w)) by the parent strain. Experiments in a laboratory scale batch fermenter, in which a higher concentration of citric acid (11.7 g/1) was achieved, proved that citric acid production using the mutant strain C. guilliermondii DT2, could be scaled up successfully from shake flask to a 2 1 fermenter. This mutant was used throughout subsequent experiments. Sawdust was selected, as the most appropriate support material to immobilize the mutant strain C. guilliermondii DT2 via the adsorption method. Experiments using different concentrations of nitrogen nutrient in defined medium using cells of C. guilliermondii DT2 immobilized onto sawdust particles, in repeated batch shake flask culture, demonstrated a marked effect of the nitrogen concentration on citric acid production. Thus, an overall productivity of 0.11 (g/l.h) was obtained using a defined medium containing 0.53 (g/l) ammonium chloride, compared to overall productivities of 0.04 (g/l.h) and 0.01 (g/l.h) using defined media containing 0.1 (g/l) and no ammonium chloride, respectively. No significant effect of nitrogen concentration on citric acid yield was observed in this investigation. In contrast, similar experiments, in repeated batch shake flask culture, for the effect of phosphate concentration on citric acid production showed no effect of phosphate on either the production rate or yield of citric acid. In bubble column culture experiments, using cells of C.guilliermondii DT2 immobilized onto sawdust, the importance of pH control in citric acid production was demonstrated. In addition, it was demonstrated that the activity of immobilized cells which have lost the ability to produce citric acid can be revived by supplying medium containing sufficient concentrations of nitrogen and phosphate. Reduction of the nitrogen concentration in the medium from 0.53 (g/l) to 0.05 (g/l), provided that the reactor was well established, showed no significant influence on citric acid productivity, but significantly improved the citric acid yield. The highest productivity of around 0.21 - 0.24 (g/l.h) at a dilution rate of 0.21 h-1, accompanied by a citric acid yield of about 10 - 11% (w/w), was reached and maintained for more than 140 hours of stable operation. Overall, it was concludcd that cells of C. guilliermondii were succesfully immobilized onto sawdust particles, and the immobilized cell reactor produced citric acid at a higher rate compared to a free cell system. In particular, a high rate of citric acid production in a bubble column reactor, operated in continuous mode, was achieved.

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  • Understanding subjective memory complaints in ageing : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University, Wellington, New Zealand

    Burmester, Bridget R

    Thesis
    Massey University

    Everyday memory difficulties are a common experience with age, and cause considerable distress for many people when they are interpreted as potential indicators of age-related disease. However, research literature examining the relationship between these difficulties (known as subjective memory complaints; SMCs) and actual memory performance on neuropsychological tests has shown mixed results, suggesting that SMCs are not a pure reflection of memory ability, but instead that their aetiology is complicated and not fully understood. Both psychological and methodological factors are also implicated, although no research has yet comprehensively examined how a combination of these factors might predict SMCs. The current research aimed to test a new aetiological model of SMCs that incorporated a range of potential confounds. It was hypothesised that SMCs would be predicted by measures of processing speed and executive functioning, and that this relationship would be moderated by measures of anxiety and depression. First, a meta-analysis and systematic review of existing research on the relationship between subjective and objective memory was conducted as a platform to inform subsequent analyses. Then, Study A addressed current variation in assessment methods by describing differences in SMCs when assessed with both an open-ended measure and a prescriptive questionnaire. Study B examined how these differences in subjective reports related to objective memory performance. Finally, Study C tested the proposed aetiological model of SMCs. Study A showed that different measures of SMCs garnered non-overlapping reports. SMCs gathered via the open-ended measure were fewer in number, but rated as more distressing, than those endorsed on the questionnaire. Spontaneous reports appeared to be more ecologically valid reflections of SMCs, although questionnaire assessments were by their nature more robust to a “catch 22” situation whereby some endorsed SMCs were not reported spontaneously (perhaps due to memory failures in themselves). Study B found that neither method of assessing SMCs produced reports that were significantly convergent with objective measures of memory functioning. Study C found partial support for the hypothesised aetiological model. SMCs (as assessed by the questionnaire) were inversely related to processing speed, but only when depressive symptoms were relatively high. Collectively, results offer important insights into the interaction of cognitive and psychological factors in explaining SMCs, and highlight the previously undelineated context in which processing speed contributes to SMCs.

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  • Evaluation of variability in a fog grass (Holcus spp.) gene pool : a thesis presented in partial fulfilment of the requirement for the Master of Agricultural Science, Massey University, Palmerston North, New Zealand

    Teow, Sian-Hock

    Thesis
    Massey University

    The utimate aim of a breeder's working collection is to utilize the genetic variation for breeding new cultivars. Before this variation can be utilised, it is necessary to obtain the description of attribute from the collection. These can either be obtained from the records of genetic resources (base collection or active collection) or obtained directly from the working collection itself. This will resulted in a huge amount of data. To bo of any value, this information need to be classified systematically, and the classification need high degree of objectivity, especially for species of no a priori knowledge. A Working collection of 160 Yorkshire Fog seed populations, from all over New Zealand, were planted out in Massey University. This formed the gene pool. During Summer 1975, 11 agronomic andi morphologic characters were scored in a semi-quantitative scale. This yield approximately 42,000 data records. These were then systematically reduced to 550 by a series of multivariate analysis techniques. The procedures of Multivariate Analysis of Variance, Multiple Discriminant Analysis and Cluster Analysis were reviewed and their computer programmes were developed. The clustering behaviours of seven agglomerative polythetic strategies were studied and compared, using the full set of characters. Most of the results concurred with studies carried out by other workers The Minimum Increment Sum of Squares strategy was found to be most suitable for this analysis. A probabilistic decision method was devised to decide objectively, the truncating point for clustering. For all set of data, the studies did not reveal any ecotypes and hence did not agree with the ecoclinal trends hypotheses (of Yorkshire Fog in New Zealand) of Jacquee.The approaches of both studies (of Yorkshire Fog in New Zealand) of Jacques. The approaches of both studies (that of Jacques and the present one) were reviewed critically and a more appropriate approach was suggested for future ecological study. Preliminary results revealed that there were a few promising groups showing agronomic desirable characters. They were promising breeding materials for future lines selection. Of all the characters studied, flowering date and clump erectness were found to be the most discriminating characters amongst groups, and the most dominant characters in clustering. These implied that selection should be beneficial, if they had moderate high predictive heretability.

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