9,403 results for Thesis, Massey Research Online

  • Viability of commercial depth sensors for the REX medical exoskeleton : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Mechatronics at Massey University, Albany, New Zealand

    Lange, Manu F

    Thesis
    Massey University

    Closing the feedback loop of machine control has been a known method for gaining stability. Medical exoskeletons are no exception to this phenomenon. It is proposed that through machine vision, their stability control can be enhanced in a commercially viable manner. Using machines to enhance human’s capabilities has been a concept tried since the 19th century, with a range of successful demonstrations since then such as the REX platform. In parallel, machine vision has progressed similarly, and while applications that could be considered to be synonymous have been researched, using computer vision for traversability analysis in medical exoskeletons still leaves a lot of questions unanswered. These works attempt to understand better this field, in particular, the commercial viability of machine vision system’s ability to enhance medical exoskeletons. The key method to determine this will be through implementation. A system is designed that considers the constraints of working with a commercial product, demonstrating integration into an existing system without significant alterations. It shows using a stereo vision system to gather depth information from the surroundings and amalgamate these. The amalgamation process relies on tracking movement to provide accurate transforms between time-frames in the threedimensional world. Visual odometry and ground plane detection is employed to achieve this, enabling the creation of digital elevation maps, to efficiently capture and present information about the surroundings. Further simplification of this information is accomplished by creating traversability maps; that directly relate the terrain to whether the REX device can safely navigate that location. Ultimately a link is formed between the REX device and these maps, and that enables user movement commands to be intercepted. Once intercepted, a binary decision is computed whether that movement will traverse safe terrain. If however the command is deemed unsafe (for example stepping backwards off a ledge), this will not be permitted, hence increasing patient safety. Results suggest that this end-to-end demonstration is capable of improving patient safety; however, plenty of future work and considerations are discussed. The underlying data quality provided by the stereo sensor is questioned, and the limitations of macro vs. micro applicability to the REX are identified. That is; the works presented are capable of working on a macro level, but in their current state lack the finer detail to improve patient safety when operating a REX medical exoskeleton considerably.

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  • The flavour of New Zealand whole milk powder : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University

    Wilson, Russell Douglas

    Thesis
    Massey University

    Results of this investigation indicate that there are certain fundamental differences in the flavour of New Zealand WMP as opposed to European (Danish) WMP. Sensory analysis has highlighted that this difference is evident in the scores which panellists give for the lactone attribute. This difference in sensory evaluation can be directly linked to differences in the lactone profiles from New Zealand and Danish WMP. Danish WMP consistently contains the two gamma lactones γ-Dodecalactone and γ-Dodec-cis-6-enolactone at levels greater than or equal to their flavour threshold values. While these two lactones are generally absent from New Zealand WMP. The presence of γ-Dodecalactone and γ-Dodec-cis-6-enolactone in WMP has been demonstrated to be related to the diet of the cow. By the addition of a grain concentrate consisting of 85% oats, 10% sunflower seeds and 5% barley it was possible to increase the levels of γ-Dodecalactone and γ-Dodec-cis-6-enolactone to the point where the sensory panel was able to differentiate WMP's in respect to the presence or absence of these compounds. There is the inference that the presence of the gamma lactones in WMP is also a function of dairy breed with Friesian cows showing a greater capacity than Jersey or mixed Jersey/Friesian cows to produce these flavour compounds. Also diet may be an important factor with the lipid content and fatty acid composition having an influencing the level of gamma lactones produced. Analysis of the flavour volatiles from fresh New Zealand milkfat has indicated a possible causative role for terpenoid compounds in the distinctive "green/grassy" flavours often present. In particular such compounds as D-Limonene have been shown to be present in samples of New Zealand milkfat and when added to New Zealand milkfat has a tendency to increase the "green/grassy" flavour score. However this does not discount the contribution of compounds such as hexanal which was also detected in New Zealand milkfat.

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  • Laser applications to analytical ultracentrifugation : a thesis presented to Massey University, Palmerston North, New Zealand in partial fulfilment of the requirements of Doctor of Philosophy

    Lewis, James Anthony

    Thesis
    Massey University

    The work of Svedberg and his collaborators in the early 1920's heralded the use of centrifugal fields for the study of macromolecular systems. Following this work the developments in both theoretical and experimental aspects have been dramatic, so much so that the majority of current researchers take the use of the analytical ultracentrifuge for granted as a basic tool for the determination of molecular weights of macromolecules. The latter is justified in view of the theoretical and experimental evidence to date, and reviews citing original references and covering the state of the art from its inception to the present day are available.

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  • Rotordynamics in alternative energy power generation : a thesis presented in fulfilment of the requirements for the degree of Master of Engineering in Mechatronics at Massey University, Albany, Auckland, New Zealand

    Cortes-Zambrano, Ivan

    Thesis
    Massey University

    This thesis analyses and discusses the main alternative energy systems that work with rotordynamics machines to generate power. Hydropower systems, wave and ocean energy, geothermal, gas turbines, wind power, tidal energy and biofuels are the most important systems that use rotating shafts to generate power. Descriptions of the principles of vibration follow with analysis of rotordynamics. The Jeff rotor, fluid film bearings and magnetic bearings are explained. The protection of the environment is one of the most important features of renewable energy and biofuel is a crucial area. Fossil fuels are a limited resource and burning them contributes to carbon dioxide levels with catastrophic effects for the atmosphere. This thesis analyses the biofuels process in electricity generation and overviews the topic of biofuels for transport. The undesirable effects of pollution from burning fossil fuels, an increase in international petroleum prices as well as the risk of using nuclear power have combined effects that illustrate the importance of research in this area.

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  • What are the drivers of rural land fragmentation in the Tasman district and what have been the planning responses? : a thesis presented in partial fulfilment of the requirements for the degree of Master of Resource and Environmental Planning, Massey University, Palmerston North, New Zealand

    Watson, Helen Frances

    Thesis
    Massey University

    Rural land use in the Tasman District of New Zealand is characterised by fragmentation of farming land, driven by a mix of historical land use patterns, global influences, and political decision-­‐making. Colonial farmers developed subsistence farming on small allotments of mixed productivity. Pockets of highly fertile land supported the development of small-­‐scale horticultural industries and the region’s good climate and high amenity value have made it a desirable destination for urban-­‐employed migrants seeking lifestyle opportunities. The fragmentation of rural land occurs via subdivision, a process that is administered by the local district council, regulated by a district plan framework and land-­‐use consent mechanisms. Analysis of Tasman District plans and policy, case law, and subdivision data, reveals a regulatory process that is failing to limit ongoing land fragmentation with increasing numbers of subdivision applications and new allotments and dwellings developed on the most productive land.

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  • Endogenous protein flow in the gut of the simple-stomached mammal : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Physiology at Massey University, Palmerston North, New Zealand

    Hodgkinson, Suzanne Marie

    Thesis
    Massey University

    The set of studies was undertaken to examine different aspects of the measurement of endogenous ileal nitrogen and amino acid loss in simple-stomached mammals and specifically to investigate the effect of the concentration of protein and peptides in the diet on endogenous ileal amino acid flows. Seven separate studies were conducted using rats and pigs. 1. The aim of the first study was to determine whether endogenous nitrogen (N) and amino acid flows at the terminal ileum change over time in the growing pig fed a protein-free diet. Male pigs (n=7, mean bodyweight 82 kg) with surgically implanted post-valve T-caecum (PVTC) cannulas received a casein-based diet for 8 days after which food was withheld from the pigs for 24 hours. The pigs then received a protein-free diet for a further 8 days during which time ileal digesta were collected continuously via the cannulas from 1300h to 1800h on each day. Endogenous ileal N and amino acid flows were determined on the digesta. There were no significant (P>0.05) effects of the duration of feeding of the protein-free diet on endogenous ileal total N or amino acid flows except for the amino acids glycine and cysteine, the mean flows of which significantly decreased over the 8-day experimental period (P0.05) differences from 1200h - 0800h. The ratio of endogenous N to chromium at the terminal ileum was also relatively constant with no statistically significant (P>0.05) differences from 1300h -0800h. The net outcome of endogenous protein secretion and reabsorption in the small intestine appears to be relatively constant over time in the meal-fed animal. 6. The aim of experiment 6 was to determine whether dietary peptide concentration affects endogenous ileal N and amino acid flows in the growing pig. Entire male pigs (n=8, mean bodyweight 33 kg) had PVTC cannulas surgically implanted. The pigs received the diets (0, 5, 10 and 20% EHC) for 8-day periods in a Latin Square design with a basal casein-based diet given to the pigs for 6-day periods in between the experimental diets. Digesta were collected continuously for 24 hours on each of the fifth and eighth days. The endogenous ileal N and amino acid flows were determined directly for pigs receiving the protein-free diet or after centrifugation and ultrafiltration (10,000 Da MW cut-off) for pigs on the EHC-based diets. Mean endogenous ileal N flows were 1753, 1948, 2851 and 5743 μg/g DMI when the pigs received diets containing 0, 5, 10 and 20% EHC, respectively. There was a significant (P<0.0001) increase in endogenous lysine flow through the terminal ileum.

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  • The effect of condensed tannin upon the protein nutritional value of solvent extracted cottonseed meal for ruminant and monogastric animals : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University

    Yu, Feng

    Thesis
    Massey University

    A series of indoor experiments were conducted at Massey University and AgResearch Grasslands, Palmerston North, New Zealand, to study the effect of cottonseed condensed tannin (CT) upon the nutritional value of solvent extracted cottonseed meal (CSM) for ruminant and monogastric livestock. Ruminant nutrition experiments were conducted using samples suspended in situ in the rumen of fistulated sheep and by incubating samples with rumen fluid in vitro, to study effects upon solubility and degradability of cottonseed proteins. Monogastric nutrition experiments were done initially with laboratory rats as a model for production animals such as the pig, and then with pigs. In all cases half of the animals were supplemented with polyethylene glycol (PEG; MW 3500). PEG specifically binds and inactivates CT and can be used to deduce the effects of CT by comparing control animals (CT acting) with PEG supplemented animals (CT inactivated). 1. Experimental varieties of cottonseed and of industrial CSM were analysed for extractable and bound CT and free gossypol, crude protein, oil and fibre. CT was present in the hulls of all varieties, with higher concentrations recorded for high tannin and glandless selections (55 g kg-1 and 58 g kg-1 DM) than for the multiple host plant resistant and high gossypol selections (38 g kg-1 DM). CT was present in trace amounts in the kernels of high tannin selections, but was not detected in the kernels of all other selections. On average for the hulls of all varieties, approximately 22, 60 and 18% of total CT was present in the extractable, protein-bound and fibre-bound forms, respectively. Free gossypol was mainly found in the kernels, with negligible amounts being found in the hulls of the experimental varieties. Kernels of high gossypol selections contained higher concentrations of free gossypol (18 g kg-1 DM) than kernels of multiple host plant resistant, high tannin and commercial selections (10-12 g kg-1 DM), with free gossypol concentration being very low (0.8 g kg-1 DM) in the kernels of glandless cottonseed. A negative correlation (r = -0.50, P 10,000) fraction affords an estimate of endogenous loss. Inclusion of hulls in the EHC based diet increased ileal flow of total N (1387 vs. 1623 mg kg-1 dry matter intake; p is due to their content of CT and the cause of the other 50% is unknown. As there is no CT in cottonseed kernels, this explains the lack of response to PEG when the diet does not contain cottonseed hulls. The study has also shown that the large amount of heat applied during normal commercial CSM processing reduces the digestion of amino acids by monogastric animals. A combination of heat and CT from hulls is especially damaging for lowing ileal amino acid digestion in monogastric species, particularly for the limiting essential amino acids lysine and threonine.

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  • Endophytic perennial ryegrass and reproductive performance of the ewe : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University

    Watson, Richard Hart

    Thesis
    Massey University

    A series of grazing and indoor trials were conducted to investigate the effects of perennial ryegrass infected with Neotyphodium lolii and its toxins on the reproductive performance of the ewe. Comparisons made were in ovulation rate, conception rate, lambs carried at scanning and lambs born per ewe, milk production and lamb growth rate between groups of ewes grazing either endophyte-infected (E+) or endophyte-free (E-) perennial ryegrass. Differences in ewe liveweight and its relationship with feed intake were also determined. More intensive trials were conducted to examine the effects of endophyte toxins on the endocrine systems that regulate the oestrous cycle and lactation. In a 4-year grazing trial in the Manawatu there were no significant differences in ovulation rate, conception rate, scanning % or lambing % between the E+ and E- groups in any year of the trial. Mean mating date was 1.8 days later (P<0.001) in the Ev+ ewes than in the Ev- ewes in Trial land in the high temperature treatment in Trial 2. A grazing trial in which slow release chromium oxide tracer was administered to ewes and lambs grazing either E+ or E- ryegrass pasture showed that feed intakes were significantly lower in the ewes and lambs grazing E+ ryegrass compared with ewes and lambs grazing E-ryegrass. Differences in feed intake between the E+ and E- groups were related to liveweight and liveweight change. There were also differences in grazing behaviour between the E+ and E- groups. Ryegrass components of the pasture, and especially the leaf-sheath, were less acceptable to ewes and lambs grazing E+ than E- pastures. It is concluded that the toxins produced by the endophyte, N. lolii, commonly found in perennial ryegrass, have the potential to reduce fertility, milk production, lamb growth rate and the liveweight of ewes. The range of toxin levels normally associated with E+ ryegrass pastures appears to be too low to cause large negative effects on reproductive performance. However, some small effects were observed such as a delay in mating, a reduction in milk production, and a higher incidence of dry ewes in ewes grazing E+ ryegrass pasture. Ewes and lambs grazing E+ ryegrass pasture have lower liveweight gains, which is associated with lower voluntary feed intakes. Chronically lower liveweight in ewes associated with grazing E+ ryegrass is likely to reduce life-time performance of the ewes.

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  • Ultrastructural studies on horse ligaments : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biophysics at Massey University

    Davankar, Sachin Padmakar

    Thesis
    Massey University

    This thesis has been devoted to studying one of the largest structural units present in most connective tissues - the collagen fibriL Diameter distributions of collagen fibrils from horse ligaments have been investigated as a function of age. A fairly complete age-related study of collagen fibril diameter distribution was targeted during this work. The ligaments (lateral collateral ligament, medial collateral ligament, radioscaphoid ligament, lateral pisoformometacarpal ligament and scaphocapitate ligament) were sampled from horses of ages one year, two-and-half year, five year, six year and eleven year. Electron microscopy methods were employed and corresponding electron micrographs were obtained from transverse sections. These were used to calculate a mean diameter and mass-average diameter of the collagen fibrils. Individual histograms were plotted showing the frequency and mass distribution of the fibrils versus the diameter at each of the ages studied. The data obtained have been related to the mechanical properties of the ligaments and their mode of growth. The diameter distributions obtained clearly reflect the mechanical needs of the ligaments during various stages of maturation. Results from a previous study of these ligaments at one particular age (four years) have been compared and found to be compatible with the results obtained during the course of this study. The effect of training on collagen fibril diameter distribution of horse ligaments has also been discussed.

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  • Evaluating the usefulness of a comparative farm programme : the Opotiki case study : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Agricultural Science in Farm Management at Massey University

    Romano, Richard Lachlan

    Thesis
    Massey University

    Bay Milk Products comparative farm programme was designed with the goal of achieving an increase in milk production from its suppliers. The company had identified the need to increase milk production to improve the efficiency of the dairy plant's utilisation. This goal has changed in the last year and now focuses on profitable milk production (as the plant has reached maximum capacity). Some evidence (Deane, 1992; Johnson 1993) suggests that comparative farm programmes do not bring about an increase in production on farms surrounding the comparative farm. This study investigated the issues of attendance at comparative farm field days from the farmer's perspective. A simple mail survey was used to establish farmer attendance at the Opotiki comparative farm field days. Four farmer case studies (two attenders and two non-attenders) were then used to enable the researcher to gain a farmer's perspective of the issues surrounding the comparative farm programme. Theses issues were then addressed in a mail survey so that all farmers in the Opotiki area could rate, score, agree/disagree with the issues the case studies had identified. The study has shown that nearly all suppliers, no matter whether they attended the comparative farm field days regularly or not were aware of the programme. 24% (n=117) of respondents were in attendance at each field day. 17% (n=82) of the respondents to the second mail survey considered themselves regular attenders of the comparative farm field days and found the field days to be worthwhile. All of the regular attenders used some of the information generated from monitoring on the comparative farm back on their own farms. Evidence from the case studies suggested that the non-attenders to the field days were also using information generated from monitoring on the comparative farm. The non-regular attenders came in contact with this information through reading the monthly company magazine Update, which contained detailed information from the comparative farm and which 94% of all respondents indicated they read regularly. The comparative farm programme was considered to be a useful source of information for farmers. This usefulness of the comparative farm programme presumably reflects benefits that the farmers believe they are receiving. However using only production orientated parameters to evaluate a comparative farm programme overlooks other benefits of the programme. The study has identified the need for a more indepth investigation into defining criteria which can be used to evaluate comparative farm programmes. In particular there is a need for more research in the area of what information farmers are using to make changes on their farms, and how this information is used.

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  • The prevalence of congenital limb deformities in a population of New Zealand standardbred foals and their influence on racing success : a thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Massey University, Palmerston North, New Zealand

    Stowers, Nikita

    Thesis
    Massey University

    This thesis reports on the retrospective studies carried out on two Standardbred studfarms in New Zealand that aimed to describe and investigate the prevalence of, and risk factors for, congenital limb deformities over the 2004/05 and 2005/06 breeding seasons. A historical cohort study of 1,189 horses was used for describing the prevalence of limb deformities over two breeding seasons. Limb deformitiy data were routinely collected within one week of birth and foals were only scored once. Foals were described as either having a limb deformity or not. Risk factors investigated were sex, mare age, parity, farm, season, birth month and sire. Simple descriptive statistics were used to describe the prevalence of limb deformities, types of limb deformities and, treatments used. Univariable and multivariable logistic regression was used to investigate the risk factors for limb deformities. Within the multivariable model it was found that birth month, mare age, farm and season were all associated with the prevalence of limb deformities. A subset of the historical cohort, consisting of all foals born in the 2005/06 season (n=627) was analysed to investigate the association between limb deformities and subsequent racing success. Univariable and multivariable logistic regression and linear regression were used to investigate the association between limb deformities, and racing success. Other variables including birth month, mare age, farm and sex and the association of these with racing success were also investigated. In the final multivariable model, birth month and sex were significantly associated with total starts of the racehorse at the completion of their 3-year-old season and birth month was significantly associated with total stakes.

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  • Ration balancing in New Zealand dairy farm management : a case farm simulation study : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Farm Management at Massey University

    Uribe, José V

    Thesis
    Massey University

    New Zealand dairy fanners are amongst the most cost effective producers of milk in the world. Nevertheless the genetic potential of New Zealand cows for milk production remains substantially underutilised. The present relatively low milksolids production per cow is a consequence of pasture-based feeding systems that do not provide all of the nutrients necessary for high (>30kg/cow/day) milk production. A potential means to increase per cow production is to balance pasture diets to provide the correct quantities and ratios of nutrients to meet target levels of milksolids production. A review of the information available on the nutrient characteristics of feeds available in New Zealand for dairy cattle was completed. This indicated that most feed sources are documented only in very simple nutritional terms and generally few of the parameters necessary for ration balancing are included. Also regional and seasonal variation in feed quality is poorly defined. Implementation of ration balancing programs on dairy farms will require the development of a more comprehensive feed database, especially for forages. The simulation model UDDER was used to investigate alternative strategies to profitably increase production per cow on a case study dairy farm. This analysis indicated that extending lactation by 30 days and supplementing pasture in early lactation with maize silage could increase milkfat yield by 17.9 kg per cow and the annual gross margin by $78.9 per cow. Thus there appears to be scope to profitably increase production per cow on the case study farm. However, UDDER is an energy-based model and does not consider the nutritional composition of the cows daily feed intake. CAMDAIRY, a computer program for analysing dairy cow rations, was therefore used to evaluate the nutritional adequacy of the diets "fed" to the cows by UDDER. This analysis suggested that the diets provided excess rumen undegradable protein (RDP) and as a consequence of this milk production was likely to be overestimated by UDDER. A diet that provided nutrients for higher levels of milk production was then formulated. The benefits of that diet were calculated using a spreadsheet partial budget that considers both immediate and carry-over effects of supplementation on financial returns. This showed that the diet formulated by CAMDAIRY could increase profit by $7.93 per cow. It was concluded that ration balancing would be a useful aid to feed management on New Zealand dairy farms, but requires feed and animal monitoring systems to be put in place to determine the type(s) and period(s) of supplementation required. Ration balancing software such as CAMDAIRY should be used with caution until it has been more widely validated for New Zealand pastoral feeding systems. In particular this study suggests that further research on the utilisation of pasture protein is required.

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  • Paradoxes in women's health protection practices : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Nursing Studies at Massey University

    Page, Aroha Evelyn

    Thesis
    Massey University

    The study explored the basis of the relatively low uptake of cervical screening and practice of breast self-examination among New Zealand women. Consistent with an interpretative approach to social phenomena it was anticipated that part of the explanation would lie in the meanings which women attach to health in general and to these specific healthprotecti'() IJ practices. Theoretical sampling was effected by semi-structured interviews with 45 women. Transcripts of these interviews provided the substantive data which were then analysed by the process of constant comparative analysis and other grounded theory strategies for analysis. The concept of a health-protectix-..o paradox centred around the core-variable 'vigilanceharmonizing' which was generated to reconcile the seeming inconsistencies within, and between, individual women and their health protection practices. This conceptualization was developed from the substantive data in order to provide a model designed to increase the effectiveness of nursing interventions for this area. The model, by illuminating processes from the client's perspective then can indicate those processes most suitable for incorporation in effective health education measures designed to promote the uptake of cervical screening and breast self-examination by women. As an adjunct to the study, a breast cancer case history is presented which shows the theory-in-use. The use of this case-history lies in the fact that it shares the substantive area of inquiry which serves to accentuate the viability, relevance and applicability of the grounded theory.

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  • Investigation of naturally occurring osteoarthritis in the metacarpophalangeal joints of wild horses : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University

    Cantley, Charlotte Emily Louise

    Thesis
    Massey University

    The purpose of this study was to assess the site, prevalence and characteristics of lesions affecting the proximodorsal aspect of the first phalanx (P1) in the forelimbs of wild horses. An investigation was made of the metacarpophalangeal joints of 22 wild New Zealand horses with a mean age of 7.36 + 3.27 years (range 2 - 14 years). The articular surfaces of the metacarpophalangeal joints were stained with Indian ink and macroscopic lesions on the medial and lateral eminences of P 1 were graded. Radiographs were taken of 2mm thick sagittal bone slabs sawn from both the lateral and medial eminences of proximodorsal first phalanx. The subchondral bone mineral density for five regions on the proximo-dorsal aspect of each bone slab was determined using a Norland XR-26 bone densitometer. Histological sections of the bone slabs were then prepared and the articular cartilage lesions on the proximo-dorsal aspect of Pl were assessed using both subjective and objective scoring methods. Subjective assessment of cabinet radiographs showed subchondral bone sclerosis to be greater in those horses with severe articular cartilage damage. The subchondral bone mineral density also increased with age and with increasing severity of lesions in the overlying articular cartilage. Ossicles with a distinct trabecular bone pattern were identified at the proximo-dorsal margin of P 1 in eight specimens from 5 horses. The macroscopic and histological articular cartilage scores increased significantly with age and the lesions were more severe on the medial compared with the lateral eminence of Pl. The study demonstrated cartilage changes, wear lines and subchondral sclerosis, consistent with osteoarthritis in the metacarpophalangeal joint of wild horses. The severity of the changes increased with age. There was a significant relationship between subchondral bone sclerosis and overlying cartilage changes in the proximo-dorsal aspect of Pl. The observations represent an age-related osteoarthritic process that may be present in all horses.

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  • Adsorption of sulphate by soils : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Soil Science at Massey University

    Marsh, Kenneth Blair

    Thesis
    Massey University

    Studies of sulphate adsorption, phosphate sorption and surface charge on soils of varying anion sorption ability which had been incubated, each with several rates of calcium hydroxide, have indicated that: (i) The amounts of both sulphate and phosphate sorbed from 0.1M NaCl can be correlated with surface positive charge, but whilst there is a 1:1 relationship between the amounts of sulphate adsorbed and surface positive charge phosphate is sorbed in amounts well in excess of the amounts of positive charge present. (ii) Although there is a requirement for some positive charge on the surface before sulphate adsorption can occur in both 0.1M NaCl and 0.025M CaCl2, there is a strong selectivity for sulphate over non-specifically adsorbed ions such as chloride. (iii) Sulphate is adsorbed from 0.025M CaCl2 in excess of the amounts of surface positive charge initially present (y = 1.51x + 1.45), an observation which is consistent with a closer approach of sulphate to the surface in the presence of calcium such that the actual surface charge is modified. These findings point to a predominantly electrostatic link between sulphate and the surface, with the changes in sulphate adsorption with pH being dependent on changes in surface positive charge. Sulphate adsorption was strongly reduced (10 - 60%) by increasing pH, and in a study of competitive sorption was also significantly (10 - 30%) reduced by addition of phosphate. An investigation with one soil showed that the measured charges in sulphate adsorbed on phosphate addition were highly correlated with measured changes in surface positive charge, and there was some evidence for phosphate having a larger effect on surface positive charge at low pH.

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  • Hauora : a socio-cultural perspective : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University

    Olson, Charles Smith

    Thesis
    Massey University

    The present study investigates the role that socio-cultural factors have had on the health of Maori. To date most explanations for observed health disparities between Maori and non-Maori have been found to be inadequate and may actually be due to socio-cultural factors. Supporting this suggestion are health differences between younger and older Maori since the urbanisation of the 1950's and the similarities Maori have with other ethnic minorities globally. Measures of Maoritanga were created in the present study and completed by 128 subjects. These were used to divide the sample into acculturated, partially acculturated and enculturated Maori. Groups differing in enculturation, and gender, were compared on a number of health issues. Health was assessed in terms of subjective wellbeing, general distress, physical symptoms, and chronic illness. Utilisation of Pakeha and Maori health systems were also examined as well as five health behaviours that have been found to differ between Maori and non-Maori. Although the Maoritanga measure appeared to be highly reliable, it failed to find any health differences between levels of enculturation. However, females with low self-reported Maoritanga were found to exhibit significantly more physical symptoms and general distress than females with high self-reported Maoritanga. For the five health behaviours, differences were found between males and females but not between levels of enculturation. There were some differences in the way that different Maori utilised Pakeha and Maori health systems. It appears that culture does have an important role in the health of Maori consequently more indepth investigation is required.

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  • Cultural identity and academic achievement of Māori undergraduate university students : a thesis presented in partial fulfulment of the requirements for the degree of Master of Science in Psychology, Massey University

    Bennett, Simon Te Manihi

    Thesis
    Massey University

    Cultural identity, academic outcome and psychological wellbeing were investigated among a non-random sample of 72 undergraduate Māori university students studying at Massey University. Student problems were examined to identify the types of difficulties that were most prevalent among this population. The relationships between student problems and academic outcome, and student problems and psychological wellbeing were then examined to assess the degree to which cultural identity moderates these relationships. Major findings are that (a) there are consistent negative relationships between student problems and grade point average, and student problems and perceived stress levels; (b) cultural identity is associated with a number of positive psychological and educational outcomes; (c) cultural identity moderates the effect of student problems on grade point average in that a high degree of problems were associated with decreases in grade point average among respondents with low cultural identity, while among respondents with high cultural identity student problems had little negative effect on grade point average; (d) cultural identity moderates the effect of student problems on perceived stress in that under conditions of low problems, students low in cultural identity have significantly higher levels of perceived stress in comparison with students high in cultural identity. Despite limitations the findings have important implications for Māori students, deliverers of tertiary education, tertiary education providers, and those involved in the development and implementation of tertiary education policy. The findings also highlight the need for further research aiming to optimise positive academic and psychological outcome among Māori students.

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  • The governance of sustainable agriculture in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Politics at Massey University, Manawatū, New Zealand

    Beecroft, Kate

    Thesis
    Massey University

    The externalities associated with agriculture mean that a turn to sustainable farming practices by farmers is essential. However, those at the centre of such a turn have complex relationships to the structures of governance that regulate, order and control socio-economic life. Governance signals a shift to a wide range of governance mechanisms that are not anchored in the sovereign state and the mechanisms that regulate agriculture and the agrifood sector have changed significantly in recent years. This thesis [and briefly restate thesis question]. Drawing on two constructs from the theoretical and applied governance literature and the agrifood literature I examine farmer perceptions of hierarchy, the market and networks and the spatial locations of these new forms of governance in regard to biological farming practices. I conclude by arguing that there is a strong case for considering governance as the new way in which agriculture is regulated, controlled and influenced. At the forefront of this devolution of power away from central government is market-based regulation and control. The implications of such restructuring for the proliferation of sustainable agricultural practices means the strengthening of market instruments is needed to bolster sustainable farming. Furthermore, funding by central government is considered necessary by farmers in order to establish a strong case for the success of sustainable farming practices.

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  • Kaupapa Maori and responsiveness : management responsiveness to Maori health issues in the reformed health service of the 1990's : a thesis presented in partial fulfilment of the requirements for the degree of Master of Social Policy, Department of Social Policy and Social Work, Massey University, Aotearoa

    Mackay, Betty

    Thesis
    Massey University

    This thesis is about the responsiveness of the health system and health services to Maori needs. It examines the relationship of the Treaty of Waitangi to health and the commitment of organisations to biculturalism in health care provision. It focuses on the poor health status of Maori people and explores the issues of racialism, racism and exclusion as factors in the health and wellbeing of Maori people by drawing on literature, day to day observations and recordings as well as the responses of ten health service managers to the idea of biculturalism and the low status of Maori health. It takes the position that Maori people have been and continue to be disadvantaged by monocultural attitudes, beliefs and practices in the health system and that managers have the power to change that. The time it was written in was a time of major restructuring in health and encompassed the change from Area Health Boards through the funder provider split to Regional Health Authorities as purchasers and Crown Health Enterprises as providers of services. Change was everywhere, yet the major inequality between Maori and non Maori health status in Aotearoa remained stable. The thesis begins and ends with the Treaty of Waitangi, thus the past becomes the present and the future, for as the Royal Commission on Social Policy notes: The Treaty is always speaking. It has relevance to all economic and social policies. Not.only must the past be reviewed in the light of its principles, but the Treaty's promise must also be seen as fundamental to those principles, which underlie social well being in years to come. (Royal Commission on Social Policy. Vol. 2.3.-151.)

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  • Preparation of nano- and microemulsions using phase inversion and emulsion titration methods : a thesis presented in partial fulfilment of the requirements for the degree of Master of Food Technology at Massey University, Auckland, New Zealand

    Wang, Yue

    Thesis
    Massey University

    The formation of nano- and microemulsions with droplet size smaller than 100 nm in diameter and stabilised by non-ionic surfactants was investigated by using two different methods, emulsion phase inversion and emulsion titration. A series of ternary systems consisting of three components (lemon oil, Tween 20 or 80 and water) were prepared at different ratios via gentle agitation by the phase inversion composition method involving the spontaneous formation of microemulsion. The phase behaviour and nano- and microemulsion formation of the ternary mixtures prepared were characterised by visual observation for their phase separation and optical clarity (e.g. transparency and opacity). The samples were also analysed for their particle size and size distribution, viscosity, conductivity and birefringence. As a consequence, phase diagrams based on two different types of small molecule surfactants (Tween 20 or Tween 80) were constructed which define the ratios of three components in the composition of the ternary mixtures that allow the formation of oil-in-water (o/w) or water-in-oil (w/o) nano- and microemulsions. Overall, the o/w microemulsions were found to form at a small region of the ternary phase diagrams with a relatively large ratio of water, compared to w/o nanoemulsion, along dilution lines 1 and 2. On the other hand, w/o microemulsions were determined at the corner of surfactant-rich region along dilution lines 1, 2, 3 and 4 in the ternary phase diagrams. Between the two ternary phase diagrams based on Tween 20 and 80, there were some differences in their composition regions responsible for the formation of nano- and microemulsions as well as for other types of phases formed, including bi- and multiphase, liquid crystals, gel and coarse emulsions. In this study, nano- and microemulsions were also produced by a method called =titration method‘ involving a two-step process; i) preparation of non-ionic small molecule surfactant-stabilised o/w emulsions by high pressure homogenisation and ii) titration of the o/w emulsions into non-ionic surfactant micelle solutions. Types and concentrations of surfactants (Tween 20, 40, 60 and 80) and oils (sunflower oil, lemon oil, tributyrin, isopropyl myristate and Imwitor 308) were investigated for their influence on the solubilisation of oil molecules from emulsion droplets into surfactant micelles, thus the formation of nano- and microemulsion. The results showed that Tween 60 and Tween 80 had the better capacity of oil droplet solubilisation compared to Tween 20 and Tween 40. The system containing a higher concentration of 2 wt% Tween 80 micelles had the larger capacity of droplet solubilisation than the other systems containing 0.5 wt% or 1 wt% Tween 80 micelles. In terms of the types of oil used, microemulsions could be fabricated using lemon oil, tributyrin, isopropyl myristate and Imwitor 308, whereas it could not be formed by using sunflower oil due to its high viscosity. Among the oils with relatively low viscosities, the order of the maximum amount of oil incorporated in 1 wt% Tween 80 micelles was Imwitor 308 > lemon oil > isopropyl myristate > tributyrin. This implies the lower viscosity oil has a higher rate of solubilisation in non-ionic surfactant micelles. The effects of pH, salt concentration and heat treatment on the stability of microemulsions were also determined. The results found that the nano- and microemulsion systems prepared by the emulsion titration method were relative stable to pH and ionic strength but sensitive to thermal treatment. This study provides useful information for the rational design of transparent nano- and microemulsions as delivery systems potentially for bioactive compounds for applications in food, beverage and non-food areas.

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