3,262 results for 1900, Doctoral

  • A study of some New Zealand natural products.

    Jogia, Madhu Kant (1985)

    Doctoral thesis
    University of Otago

    xii, 348 leaves :col. ill. ; 30 cm. Includes bibliographical references. University of Otago department: Chemistry

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  • Haematology and inflammation in infections of farmed red deer (Cervus elaphus)

    Cross, John Philip (1991)

    Doctoral thesis
    University of Otago

    xiii, 180, i, 39 leaves, [1] folded leaf :ill. (some col.) ; 30 cm. Includes bibliographical references. University of Otago department : Microbiology

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  • Studies on the foaming properties of proteins : the role of soluble leaf proteins and other surfactants in the persistence of bloat foams : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biochemistry at Massey University

    Jones, William Thomas (1971)

    Doctoral thesis
    Massey University

    Methods were developed for the isolation of the soluble leaf proteins in as pure a form as possible and free of any phenoloxidase products. This protein material was separated into two fractions (Fraction 1 and Fraction 2 proteins). A detailed study of the foaming properties of these soluble protein fractions was made so that the conditions necessary for the production of stable foams from these solutions could be evaluated. The nature of the foams derived from bovine salivary secretions and the soluble proteins of the holotrich protozoa were also examined. The foams derived from the leaf and protozoal proteins were rigid and of high stability only when the foams were of high compressive strength. In contrast the salivary secretions produced foams of low compressive strength but high persistence. For protozoal proteins and Fraction 1 protein of white clover and red clover the optimum pH for foam production was close to pH 5.8 to 5.9 and for the plant Fraction 2 proteins in the range 5.1 to 5.4. The foams derived from bovine salivary mucoprotein was unaffected by changes in pH over the range 3.5 to 7.5. The foams generated in vitro from rumen liquor were of low compressive strength but extremely high persistence, and their properties were very different from those of the foams generated from either the plant or protozoal proteins except that they showed maximum foam persistence in a similar pH range. The concentration of Fraction 1 protein in the rumen liquor was below the minimum concentration required to produce stable Fraction 1 protein foams. Of this low concentration only 24% was surface denatured in production of these very stable rumen foams. The significance of this result is discussed. Apart from the low level of Fraction 1 protein, other low molecular weight proteins together with a major component containing carbohydrate as well as protein, were observed on analysing the rumen liquor by acrylamide gel electrophoresis and cellulose acetate electrophoresis. This major component resembled salivary mucoprotein in its schlieren profile in an analytical ultracentrifuge. This material was isolated by preparative ultracentrifugation and some of its properties examined. It was not precipitated by trichloracetic acid, unlike the protozoal and plant proteins, but was precipitated by 60% ammonium sulphate, 80% ethanol, and an equal volume of 1% cetavlon. The antibody to this material gave a positive precipitin reaction with the salivary mucoprotein, the sensitivity of which could be increased by incubating the salivary mucoprotein with neuraminidase, an enzyme which removes the sialic acid from the mucoprotein. molecule. The significance of these findings in relation to other work is discussed. The action of various surfactants that have been implicated in the bloat syndrome on the foaming properties of Fraction 1 protein foams was examined. Thus calcium was found to increase the rigidity of Fraction 1 protein foams, slightly increase the rigidity of Fraction 2 protein foams at high calcium concentrations only, but was without effect on salivary mucoprotein foams. Sodium polygalacturonate increased the persistence of Fraction 1 protein foams at concentration greater than 0.04% w/v. Two salivary secretions were examined for their effect on Fraction 1 protein foams. The first of these was bovine salivary mucoprotein, which whilst increasing the persistence of the foam, decreased its rigidity. Foams of maximum persistence were produced from solutions containing Fraction 1 protein/mucoprotein in the ratio 2/1 , w/w. The second salivary secretion examined was the oesophageal mucin. This material did not produce stable foams by itself, but was an extremely effective stabilizing agent of Fraction 1 protein foams. The most effective antifoaming agent of the polar lipids of red clover examined in this thesis, was phosphatydyl choline which at a concentration of 50 µg ml-1 completely inhibited the production of Fraction 1 protein foams. Addition of mucoprotein to lipid/Fraction 1 protein mixtures which would not support stable foams, resulted in production of extremely persistent foams. Both Fraction 1 protein and mucoprotein were essential for the formation of these foams which resembled the properties of the foams generated in vitro from rumen liquor. From this study it appeared that neither the plant nor the protozoal proteins by themselves could account for the properties of the rumen foams. The properties of the rumen foams could be reproduced by generating foams from mixtures of Fraction 1 protein/plant lipid and salivary mucoprotein. The soluble proteins and the foaming properties of extracts of bloat and non-bloat provoking legume pastures were examined. It was found that the temperate non-bloating legumes contained condensed tannins which precipitated the soluble leaf proteins and thus by removing the plant foaming agents from solution inhibited foam production from these extracts. These tannins were isolated from Lotus pedunculatus Cav., and were shown to form insoluble complexes, not only with the soluble leaf proteins, but with protozoal proteins, salivary mucoprotein, and the protein present in rumen liquor. Tannins were common in the Lotus species, but of the Trifolium species examined, they were found only in Trifolium arvense L.. The significance of incorporation of tannins into bloating pastures in an attempt to eliminate bloat is discussed. The non-bloating tropical legumes, apart from the Desmodium species, did not contain tannins but were lower in soluble leaf protein, and the bloat potential could be correlated with the compressive strength of the foams derived from extracts of these plants.

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  • The complexing of calcium and magnesium by organic plant constituents : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy, Chemistry/Biochemistry Department, Massey University

    Molloy, Leslie Francis (1971)

    Doctoral thesis
    Massey University

    The definition, occurrence and aetiology of hypomagnesaemic tetany is discussed as an introduction to the practical implications of the present investigation. The current hypotheses, involving an unfavourable pasture chemical composition, accounting for the binding of Ca++ and Mg++ in the intestinal tract of ruminants are reviewed. The role of undigested or partly-digested plant cell wall materials is advanced as another such hypothesis, and the present investigation of the cell wall polymers of a typical pasture grass is outlined. The comprehensive analysis of the grass Yorkshire fog (Holcus lanatus) involves, initially, the extraction and purification of pectic substances, lignin, hemicelluloses and cellulose. The non-volatile organic acid content of the grass is also determined. Analytical methods are developed and evaluated in order to assess the homogeneity of these isolated cell wall fractions, and their chemical constitution investigated to aid in determining any possible relationship between cation complexing and polymer (or monomer) structure. The pectic fraction isolated from Yorkshire fog is approximately 90% polygalacturonic acid while the hemicelluloses are basically arabinoxylans with varying hexose and uronic acid content. Attempts tofractionate the predominant hemicellulose, hemicellulose B, into homogenous arabinoxylans gives inconclusive results. Most of the chemical evidence, however, indicates the presence of three discreet polysaccharides in this fraction - a simple arabinoxylan, an acidic galactoarabinoxylan and a neutral glucan. Infrared and ultraviolet spectroscopy is utilised to determine the purity of the isolated lignin as well as the presence of typical lignin functional groups. Yorkshire fog lignin has a moderate phenolic hydroxyl and -OMe content and, like most other monocotyledonous lignins, gives yields of syringaldehyde, vanillin and p-hydroxybenzaldehyde on alkaline nitrobenzene oxidation. The outstanding feature of the lignin is its appreciable content of etherified hydroxyl groups in the 4-position of the aromatic ring and the low yield of syringaldehyde. The water-soluble, non-volatile organic acids are quantitatively determined by anion-exchange resin chromatography and their identity confirmed by paper chromatography. The major acid is the tricarboxylic acid, trans-aconitic acid, which is determined spectrophotometrically. The normal plant acids, citric and malic, are present in moderate quantities while the alicyclic acids, quinic anc shikimic, are only present in minor amounts. A limited amount of data on the seasonal fluctuation of these organic fractions in Yorkshire fog is presented. Electrolytes and the concept of ionic activity are discussed in the introduction to the study of the ability of these plant fractions to bind Ca++ and Mg++ in an aqueous salt solution of cationic composition similar to that of the intestine of a ruminant. A cation exchange method is developed whereby changes in the activity of Ca++ or Mg++ on the introduction of a plant fraction into the salt solution are reflected in the cationic composition of the equilibrium resin. An investigation is undertaken of a large number of calibration solutions varying in [ca++] and[Mg++], but constant in [Na+], [K+] and [NH4+], the latter cations being present in excess as 'swamping' cations. Regression expressions relating solution cation concentration to the equilibrium resin cation concentrations are derived and used as calibration equations to determine the amounts of bound and ionic Ca++ and Mg++ in solutions in equilibrium with the plant fractions. The pectic substances, lignin and the organic acids are effective in complexing a large proportion of the solution Ca in a non-ionic form but only lignin and the organic acids display a significant complexing of solution Mg++. Except for hemicellulose B (branched) at a slightly alkaline pH, the hemicelluloses and cellulose have little ability to complex either Ca++ or Mg++. The complexing results are discussed in terms of the relationship of polymer structure to observed cation affinity. Factors involved in cation binding are: - the charge and degree of hydration of the cation itself; - distribution and degree of esterification of carboxyl groups in the polymer; - monomer conformation; - type of glycosidic linkage in the polymer; - the possibility of hydrogen-bonding and non-bonded interactions between substituents on the polymers; - solution pH. The in vivo implications of the results are finally discussed in the context of general ruminant nutrition and alkaline-earth metal absorption discussed in the introduction.

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  • The kinetics of mild acid hydrolysis of gluten and the functional properties of the modified proteins at various levels of hydrolysis : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biotechnology at Massey University

    Higgins, John Joseph (1988)

    Doctoral thesis
    Massey University

    Gluten is the mixture of proteins remaining in wheat flour after starch and water soluble components have been extracted by washing. Its unique dough forming properties are due to the structure of the proteins. A feature of the protein is the high glutamine content, about 30% of the total amino acids. A number of studies have shown that gluten's properties of insolubility and water-binding can be substantially modified by mild acid hydrolysis. The principal effect of the mild acid treatment is to hydrolyse the amide side chain of glutamine such that the amide group is replaced by a carboxyl group. In addition, it is known that hydrolysis of peptide bonds can have a large influence on the functional properties of proteins. The aims of this study were to determine the kinetics of the acid catalysed deamidation and peptide bond hydrolysis reactions, and to comment on the resultant changes in functional properties. A statistically designed experiment was used to determine the effect of temperature, hydrogen ion concentration and gluten concentration. An initial rate analysis of the results showed that reactions could be described by equations of the form: Rate of amide bond hydrolysis = k1.[Amide][H+] and Rate of peptide bond hydrolysis = k2 [Peptide] [H+] where k = koe -E/R.1/T A stoichiometric analysis of the experimental data confirmed that hydrogen ions were consumed in both reactions. A numerical solution was developed to predict the extent of reaction with time. A computer program incorporating the solution was used to simulate the reaction and test the solution. The simulation results appeared to overestimate the progress of the reaction with time. A series of ten gluten powders, hydrolysed to different extents was prepared at small pilot scale. The composition of the samples was determined and compared with the extent of hydrolysis predicted by the reaction simulation. Reasonable agreement was achieved. A selection of the functional properties of the prepared samples was examined. The quantity of alkali required to dissolve each preparation to the extent of its solubility at pH 7.6 increased markedly with the extent of hydrolysis due to the additional carboxyl groups requiring neutralization. The flavour of each preparation was exanined. A cereal flavour was found to decrease with the extent of hydrolysis. A lingering bitter flavour was found to increase with the extent of hydrolysis. The solubility of all preparations at p H 7.6 in 0.1 M phosphate buffer increased with the extent of treatment so that the most hydrolysed samples were almost completely soluble. No (significant) difference was found between freeze dried and spray dried samples. Samples prepared without dialysis showed no solubility difference from those prepared with dialysis at a similar extent of hydrolysis. The hydrophobicity of the preparations was measured using two different fluorescent probes and was found to increase with the extent of hydrolysis. The emulsion-forming properties of the preparations were found to depend on the oil used in the test, as would be expected if hydrophobicity was equivalent to the hydrophile lipophile balance, which is commonly used to classify emulsifying agents. The preparations did not, however, show the additivity properties of emulsifiers. It was also shown that only the soluble portion of the preparations was responsible for emulsion formation. The possibility of achieving deamidation of gluten using the enzymes peptidoglutaminase I and II was examined. No activity against gluten or partially hydrolysed gluten was found.

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  • A comparison of the fate of elemental sulphur and sulphate sulphur based fertilizers in pasture soils : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Soil Science at Massey University

    Phimsarn, Sathien (1991)

    Doctoral thesis
    Massey University

    Nitrogen fixation by legumes has a particular requirement for adequate soil sulphur status. Sulphur (S) is a mobile nutrient and is easily leached from aquic soil environments, therefore regular topdressing with S fertilizer is required to maintain legume vigor and pasture production in most New Zealand pasture soils. Escalating fertilizer costs have focused attention on the efficiency of use of S fertilizers, particularly superphosphate (SSP) and alternative elemental S (S0) based fertilizers less liable to leaching loss in this aquic environment. Field and glasshouse trials, using the resident clover/ryegrass sward on undisturbed soil cores (150 mm diameter, 100 mm depth) , were undertaken to determine the comparative short-term fate of SSP and different particle sizes of S0. Methods for manufacturing radioactively labelled (35s) fertilizers were developed. In addition, the effect of sheep dung on the short-term immobilization of soil and fertilizer S was also investigated. A simple computer simulation model explaining the observed transformation of soil sulphur and 35s labelled fertilizer was developed. Initially, the effect of sheep dung on the short-term immobilization of soil and fertilizer S was investigated. Very small amounts (about 2-5%) of plant (clover/ryegrass pasture) S and P, within 1 00 mm of the area surrounding the dung pellet, were derived from the dung. Under the experimental conditions that prevailed, dung S behaved as a slow release S form causing neither greater immobilization of soil or fertilizer S nor mineralization of soil organic S. It was concluded that the impact of dung return on short-term (< one year) S fertilizer fate need not be considered. An initial field trial comparing the fate of microfine S0 (< 0.010 mm) relative to sulphate-based SSP was undertaken on Tokomaru silt loam, a New Zealand yellow-grey earth (Fragiaqualf). The microfine S0 oxidized within 30 days of application but initially (up to 60 days) was slightly less effective than SSP in terms of plant uptake. Over longer periods of time (150 days) their performances were comparable. Final cumulative plant uptake at 150 days accounted for 13.6% of microfine S0 and 16.3% of the SSP-sulphate. The major transformation of 35s from microfine S0 and 35s belied gypsum In SSP to soil organic 35s forms occurred in the first 30 days after application. The organic 35s activity formed from 35s0 was twice that formed from sulphate-based fertilizer and was mainly carbon- bonded 35s in the top 33mm of the pasture soil profile. The amount of organic 35s remaining as carbon-bonded 35s decreased with soil depth and the reverse occurred for the estersulphate 35s. By 1 50 days, greater activity from the microfine 35s0 remained in the soil organics fraction than from the sulphate-35s fertilizer, indicating that more soil organicS reserves may be formed through the use of fine S0 fertilizer than from the sulphate-based fertilizer. This also indicated the advantage of using S0 in minimizing the S leaching losses in this aquic environment. An inverse dilution technique using an isotope injector developed at Massey University to uniformly label undisturbed soil cores with carrier-free 35so4= solution was used to measure the impact of S0 and sulphate-based fertilizers on the fate of soil S. Results were consistent with the labelled fertilizer technique and both techniques indicated rapid incorporation of 35s into soil organic S and that the carbon-bonded S formed was likely to be a subsequent source of mineralized S available to plants. Soil samples from the preliminary field study were used to evaluate soil preparation and extraction techniques. Soil sampling and preparation techniques were evaluated on the basis that an extract sampling the plant available S pool in soil should have the same 35s specific activity as plant growing on that soil. The average 35s specific activity in a calcium dihydrogen phosphate (CaP-S) (0.04 M) extract from a freeze-dried sample of the top 60 mm of a pasture soil was most closely related to the 35s specific activity of plants growing on that soil. CaP-S extracts from field-moist soil or 0.01 M CaCI2 extracts from field-moist or freeze-dried soils had higher specific activities than plants. lt was concluded that plants were able to extract soil S from soils which was not exchangeable with added 35so4= fertilizers during either the field experiment or extraction with 0.01 M CaCI2. The second series of field and glasshouse trials were conducted to investigate the fate of 35s labelled SSP, gypsum and S0 of varying particle sizes (0 . 1 50 m m) which had not oxidized, the major fate of fertilizer 35s, either under glasshouse or field conditions, was again in soil organic matter mostly formed in the top 33 mm of the soil. Applications of gypsum and SSP caused 35s to move to the 33-1 00 mm soil depths but there was no additional influence of P on the depth to which so4= was leached. A preliminary computer simulation model describing the fate of 35so4 =-s fertilizer was developed. The model provided a very accurate method of predicting plant uptake of S from both SSP fertilized and u nfertilized soil cores. The model also indicated that, at any particular soil depth, on average, actual rates of mineralizatio n a nd i m mobilization may exceed root uptake of S by 1.5 to 2 fold (mg S turned over per unit of S taken up by plants). The accuracy of the estimated turnover rate could not be validated because the model gave relatively inaccurate predictions of the measured movement and transformations of 35s tracer added to the soil as SSP. There was, however, relative similarity between the observed and predicted proportional distribution of 35s between soil and plant S forms. Such a distribution supported the concept of using root activity as a modifier of mineralization and immobilization rates in order to describe the extent of these processes at different soil depths. The study has emphasized the greater importance of the surface few millimeters of pasture soil in S transformations, important in the fate of fertilizer and pasture plant nutrition. There appears to be scope in manipulating S0 particle size to improve the efficiency of the S fertilizer used.

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  • Biogeochemical studies of nickel and copper in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University

    Timperley, Michael Horace (1971)

    Doctoral thesis
    Massey University

    The accumulations of various metals by some indigenous trees growing on the Riwaka Basic Complex, North-west Nelson, New Zealand, were investigated by the application of statistical techniques to biogeochemical data. Particular reference was given to nickel and copper to evaluate the usefulness of plant analysis as a prospecting tool. Preliminary investigations showed that serious errors could result from the methods of sampling plants and soils and sampling procedures were adopted to minimise these errors. In addition, errors arising from atomic absorption analysis were found to be significant for some metals. Leaves and twigs from three Nothofagus species, W.racemosa and Q.acutifolia as well as their associated soils, were collected and analysed for nickel, cobalt, copper, zinc, chromium, calcium, magnesium, manganese and potassium. The plants were also analysed for iron. These results showed that each species accumulated different, but related, amounts of various metals and that they distributed these metals in different ways between their leaves and twigs. N.truncata and N.fusca which are closely related genetically, accumulated metals to similar degrees, while N.menziesii which is not closely related to the other Nothofagus species accumulated metals to differing degrees. Relationships between the metal concentrations in the plants and in the soils were evaluated by computing correlation coefficients. The best correlations for nickel were obtained for the Nothofagus genus although the other species also showed highly significant correlations. The Nothofagus genus also showed the best correlation for copper. In view of the above results, a more extensive study of the Nothofagus genus was carried out. A second survey was undertaken in the same area in which leaf samples of this genus as well as their associated soils were collected. While the metal concentrations in the soils collected in this survey compared well to those collected previously, the metal concentrations in the plants, in general, did not show good agreement. Trend analysis was used to compare in detail the nickel and copper contents in the leaves of the Nothofagus genus with the concentrations of those metals in the soils. It was shown by comparison of the trend surfaces and residuals that the accumulation of nickel was determined primarily by the concentration of nickel in the soil, whereas for copper the accumulation by the plant was a function primarily of the specific requirement of the plant for this metal. Multiple regression analysis was used to improve the prediction of the copper and nickel concentrations in the soil from the concentrations of these metals in the leaves of the Nothofagus species, by making quantitative allowance for the processes influencing the accumulation of these metals by the plants. Improvements of between 25% and 35% were obtained at the 90% confidence level. Inter-metal ratios in the leaves were considered as possible indicators of nickel and copper concentrations in the soil but the results were discouraging. Studies were made of the locations and chemical forms of nickel, copper, zinc and iron in both freeze-dried and fresh leaves from some trees growing on the Complex. Atomic absorption spectrophotometry was used to measure the concentrations of these metals in both plant extracts and on the electrophoresis and chromatography papers used to separate the metal complexes in the extracts. Results indicated that the major part of the nickel present in the leaves was not contained in cell organelles nor was it bound to cell walls, but existed as a positively charged complex in either the cytoplasm and/ or the vacuole. Copper, zinc and iron were distributed differently with varying fractions, depending on the metal, existing predominately as anionic complexes. It was concluded that the research embodied in this thesis had illustrated the application of statistical techniques to biogeochemical studies, showed that biogeochemical prospecting for nickel in New Zealand was feasible and that methods of total analysis for metals could be applied to the study of microgram amounts of metals in biological systems.

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  • The effect of water stress on water relations, carbon isotype discrimination, and shoot and root growth of sainfoin (Onobrychis viciifolia Scop.) and lucerne (Medicago sativa L.) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Department of Plant Science at Massey University

    Mir-Hosseini-Dehabadi, Seyed Reza (1994)

    Doctoral thesis
    Massey University

    Sainfoin (Onobrychis viciifolia Scop.) is a useful forage legume regarded as having drought resistant attributes. Also, it does not cause bloat in ruminants and is not sensitive to alfalfa weevil (Hypera postica. L). Although the physiological and morphological responses to water stress of lucerne (Medicago sativa L.) are well known the responses of sainfoin to water stress have not been fully studied. In this study the physiological and morphological responses of sainfoin to water stress were investigated, with lucerne used as a reference plant. The results of the indoor and outdoor studies showed sainfoin had useful characteristics for forage production in dry conditions. Relative to lucerne it had a lower yield, due to lower leaf area, lower stem number and poor regrowth. However, sainfoin responded to water stress at least as well as lucerne. Sainfoin had a higher root:shoot ratio and a lower specific leaf area ratio than lucerne, indicating a higher allocation of carbohydrate to the roots, and a lower leaf surface area for transpiration in sainfoin than for lucerne. Water stress decreased the yield of lucerne proportionally more than sainfoin mostly due to the greater reduction in the above ground dry weight of lucerne. The indoor study of root characteristics of sainfoin and lucerne in 1m tall tubes showed that in terms of root development sainfoin responded to water stress better than lucerne. Although sainfoin had equal root mass and root length to lucerne, the root distribution of sainfoin at below 0.6 m depths was greater than for lucerne. As water stress developed sainfoin roots grew below 0.6 m earlier than lucerne roots. Sainfoin had a higher root osmotic adjustment than lucerne and also maintained higher (less negative) leaf water potential than lucerne. The stomatal resistances (Rs) of sainfoin and lucerne were equal, but Rs was not distributed equally between adaxial and abaxial leaf surfaces. The Rs of the adaxial leaf surface of sainfoin was lower and more sensitive to water stress than the Rs of the abaxial leaf surface. The different Rs of the adaxial and abaxial leaf surfaces of sainfoin was partly due to the different stomatal frequencies of the respective surfaces. Comparison of sainfoin cultivars in a climate room showed that the water use efficiencies (WUE) of Remont, Fakir, Cotswold-Common, and Eski, were similar. Remont was more sensitive to water stress than the other three cultivars, and Eski produced a greater root length and mass than other cultivars. The growth of Eski was initially slower than that of the Remont in both the indoor and the outdoor studies. However, lucerne grew faster than all the sainfoin cultivars. Over three harvests in the field the yields of Eski and Remont were similar but lucerne out yielded both sainfoin cultivars. Sainfoin produced a greater proportion of its yield earlier than lucerne, whereas lucerne distributed its yield throughout the whole season, indicating that sainfoin is adapted to regions with precipitation in only winter and spring. The results of the carbon isotope discrimination (Δ) analysis for the indoor and outdoor studies showed Δ had a negative correlation with WUE, leaf water potential, osmotic potential, and stomatal resistance, but had a positive correlation with relative water content, turgor potential, transpiration rate, and photosynthetic rate. These correlations demonstrated the usefulness of this technique for evaluating the responses of plants to water stress. The stressed plants always had lower Δ than the control plants showing the higher WUE of stressed plants. The Δ of roots was higher than the Δ of the leaves suggesting that the growth of leaves occurred in conditions that were an average drier than for the growth of roots. This was supported by the lower (more negative) water potential of leaves than roots. The Δ of the roots below 0.6 m depth was higher than the Δ of roots above 0.1 m depth suggesting the roots above 0.1m grew under higher water stress than the roots below 0.6m depth. Over three harvests in the field the Δ of Eski and lucerne were similar and the Δ of Remont was higher than for Eski and lucerne. In conclusion, sainfoin was found to have several useful attributes for growth and survival in dry regions. Of the sainfoin cultivars examined Eski was the best adapted to water stress. Relative to lucerne, sainfoin yielded less, but had a similar water use efficiency, a shorter season of growth, a greater root: shoot ratio, deeper roots and better maintenance of leaf water potential under water stress.

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  • Studies on Cooperia curticei (Ransom 1907) a nematode parasite of sheep : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy

    Ahluwalia, Jagjit Singh (1970)

    Doctoral thesis
    Massey University

    This thesis records in part I studies on the ecology of the free living stages of Cooperia curticei , both under controlled and natural conditions. At constant temperatures free living stages developed throughout the temperature range of 10-37c. At all temperatures each larval stage occupied the same proportion of the total developmental time to reach the infective stage. The relationship between the rate of development in log days and temperature was found to be linear. Under natural conditions the rate of development was most strongly correlated with mean maximum air temperature and was not significantly different to that observed under controlled conditions. When faecal cultures were kept at 10°C, 27°C and 37°C a higher proportion of eggs completed development to the infective stage at 27°C than at the other temperatures. Under natural conditions the percentage recovery was influenced by weather conditions particularly rainfall. Submergence of the free living stages in water inhibited their further development. First and second stage larvae survived longest at temperatures between 5°C and 15°C but for a much-shorter time than infective larvae. Between the extremes of -6 and 52°C, the longest survival of infective larvae was 312 days at 10°C. Techniques are described for the recovery of Cooperia curticei larvae from sample units of pasture, soil and faecal pellets. Under natural conditions the maximum survival of larvae from monthly experiments ranged from 9 - 26 weeks. Maximum survival was particularly influenced by temperature. Infective larvae survived through the winter. There was an exponential relationship between the percentage survival and percentage of larvae recovered from the herbage. Vertical migration of larvae appeared to be primarily affected by rainfall and evaporation. It is concluded that infective larvae of Cooperia curticei are available to grazing sheep throughout the year. Theoretically the nematode can complete from 9 - 11 generations in each year. Part II of this thesis records experiments on the relationship between Cooperia curticei and the host sheep. Experiments carried out in vivo and in vitro demonstrated that infective larvae of C. curticei exsheath under conditions provided by the rumen. The process of exsheathment was similar to that described for H. contortus. A series of experimental observations were made on the effect of Cooperia curticei infection in sheep using animals of differing ages, on different diets and with various sizes of infection. The prepatent period of infection was 14- 16 days. Peak egg counts were recorded 5 - 7 days after infection became patent . There after they declined gradually in sheep given 10,000 larvae but in sheep given 50,000 to 100,000 larvae the decline was more abrupt. The egg output per female worm was found to range up to 1,958 eggs per day. No clinical sign of infection was observed from any experimental animal. Body weights, wool growth and blood analyses showed no significant changes and no gross lesions or significant histopathological changes were observed. The results indicate a well balanced relationship between C. curticei and the sheep. The distribution of the C. curticei in the small intestine was skewed, and most of the worms were recovered from 5- 10 feet from the gastric pylorus. A predominance of female worms was observed at all levels of the small intestine. Maximum percentage recovery of C. curticei was observed in sheep given 10,000 larvae. Experimental animals with higher doses besides giving a lower rate of recovery showed inhibition of development and stunted growth of worms. Serum and intestinal mucus samples from infected animals were tested for precipitating antibodies by gel diffusion against five antigens. Antigens were prepared from first stage, second stage, ensheathed third stage, exsheathed third stage larvae and exsheathing fluid. Variable numbers of precipitin lines were obtained with serum and mucus from infected sheep more than 6-7 months old. Sheep 2-3 months old showed no such response but did show evidence of an acquired resistance to infection.

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  • Studies towards the chemical synthesis of the 18 kDa antigenic protein from Mycobacterium leprae : a thesis presented in partial fulfilment of the requirements for the degree of Ph. D. in Chemistry at Massey University

    Love, Stephen George (1991)

    Doctoral thesis
    Massey University

    This thesis describes the solid phase synthesis of a series of peptides from the antigenic Mycobacterium leprae 18 kDa protein and the total synthesis of the 148 amino acid protein. The peptides were synthesised using an Applied Biosystems 430A Solid Phase Peptide Synthesiser usually modified by the removal of in-line filters to the reaction vessel to allow the synthesis of the peptides using programs evolved by S.B.H. Kent. The peptides were cleaved from the peptide resin using liquid HF and purified by reverse phase HPLC. The first series of peptides to be synthesised revolved around a monoclonal antibody binding site. These peptides were SLP-1, (101-115, RILASYQEGVLKLSI), SLP-2, (111-124, LKLSIPVAERAKPRK), SLP-3, (121-134, AKPRKISVDRGNNG) and SLP-4 (109-125 GVLKLSIPVAERAKPRK). The other peptides were synthesised as a series of overlapping 20 mers covering the entire 148 amino acid sequence. These peptides are SLP-5 (1-20, MLMRTDPFRELDRFAEQVLG), SLP-6 (16-35, EQVLGTS ARPAVMPMDAWRE), SLP-7 (31-50, DAWREGEFVVEFDLPGIKA), SLP-8 (46-65, PGIKADSLDIDIERNVVTVR), SLP-9 (61-80, VVTVRAERPGVDPDREMLAA), SLP-10 (76-95, EMLAAERPRGLFNRQLVLGE), SLP-11 (91-110, LVLGENLDTERIL ASYQEGV), SLP-12 (106-125, YQEGVLKLSIPVAERAKPRK), SLP-13 (121-140, AKPRKISVDRGNNGHQTINK) and SLP-14 (136-148, QTINKTAEHEIIDA). Two other peptides SLP-15 (101-125, RILASYQEGVLKLSIPVAERAKPRK) and SLP-16 (91-115, LVLGEIVLDTERILASVQEGVLKLSI) were also synthesised. The peptides were used in immunological studies that determined the location of the L-5 monoclonal antibody binding site and showed where T-cell stimulation sites are located on the 18 kDa protein in murine systems. The synthesis of larger 50 amino acid fragments of the 18 kDa protein, peptides SLP-17 (101-148), SLP-18 (50-100) and SLP 19 (1-50) was carried out in order to determine if it was possible to synthesise the total 18 kDa protein. These fragments were synthesised in a similar manner to the previous peptides. From the synthesis of these peptides it was decided that the total synthesis of the 148 amino acid protein was possible. The synthesis of the 18 kDa protein was carried out using Kent's protocols as a single step process. The synthesis was monitored up to the 100th amino acid by ninhydrin assay with no failed couplings detected. The coupling percentages for all of the amino acids was achieved by peptide resin sequencing where the average percentage couplings were shown to be 99.49% with an overall yield for the protein on the resin of 49%. After Lo-Hi HF cleavage purification of the protein was hampered by the formation of aggregated products which proved initially to be inseparable from the protein. By sequencing some partially purified protein it was shown that under certain cleavage conditions the benzyl ether side chain protecting group was present on the threonine amino acids at positions 5 and 21. A further treatment of the protein using a hard acid-soft base mechanism with trimethylsilyl trifluorosulphonate/thioanisole was used in these cases to remove the remaining benzyl protecting groups. An attempt to overcome the aggregation of the protein involved the addition of SDS to the HF cleavage vessel. After purification the protein showed no signs of the aggregation products. A 90 amino acid fragment removed during the course of the synthesis of the 18 kDa proteien was cleaved and dissolved in 6M guanidine.HCl. After gel filtration on a Sephadex G-50 column, preparative HPLC was carried out on the isolated protein peak. The protein was then gel filtered again on a Sephadex G-50 column using 6M guanidine.HCl which separated the aggregated product to give a pure 90 amino acid protein after dialysis. The full synthetic 18 kDa protein was purified in a similar manner to the 90 amino acid fragment with the second gel filtration being carried out using a Sephadex G-100 column or a Pharmacia Superose 12 column. This provided pure synthetic 18 kDa protein in an estimated 1.8 % yield or 47 mg from this synthesis of a final 2.46 g of protein resin based on the starting protein on the resin.

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  • The neotectonics of the Wellington and Ruahine faults between the Manawatu Gorge and Puketitiri, North Island, New Zealand : a thesis presented as partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science

    Hanson, Judith Ann (1998)

    Doctoral thesis
    Massey University

    The Wellington and Ruahine Faults are two major faults of the North Island Dextral Fault Belt which formed approximately 2.5ma in response to the obliquely subducting Pacific Plate beneath the east coast of the North Island. Plate rotation has increased over time causing faulting patterns to change throw direction and strike-slip activity to increase within the Hawkes Bay area. Earthquakes rupturing either the Wellington or Ruahine Faults represent a serious hazard for this area. The purpose of this study was to establish a record of paleoseismic activity on the Wellington and Ruahine Faults which would allow future estimates of likely fault behaviour to be made. Trenches were excavated across these faults in mainly swampy environments. Within these trenches are layers of earthquake debris, layers of peat and other terrestrial sediments which have been deformed by earthquake activity. The layers of peat were radiocarbon dated to give the approximate ages of underlying or overlying earthquake debris. In many areas through which the faults pass are terraces composed of gravel which has been washed down from the axial ranges composed of Torlesse greywacke. The ages of these terraces are known due to layers of dated volcanic ash preserved in cover beds and wood preserved within. Some of these terraces have been offset by the fault. Using the known age of these terraces and the distance that they are offset by the fault, it was possible to calculate rates of fault movement during late Quaternary time. Field observations of the Wellington and Ruahine Faults reveal that the faults do not deform the areas through which they pass but rather act in response to regional deformation (within these structurally different areas). During earthquake events large blocks of land are moved both horizontally and vertically. The rate and size of these events is dependent on the regional geology where the earthquake ruptures occur. These regions are described as follows from south to north. The first region lies between Kahuki and the Ohara Depression, this is an area of prevalent strike-slip with horizontal offset rates averaging 12mm/yr for the Wellington Fault which is high by world standards. In contrast the Ruahine Fault displays little evidence of late Quaternary movement. The second region encloses the Ohara Depression which has an east-west compressional vector. Here strain is transferred from the Wellington to the Ruahine Fault thereby lowering the horizontal offset rate for the Wellington Fault to a maximum of 4.7mm/yr. The third region lies between the Ngaruroro and Tutaekuri Rivers and is a region with a north-northeast compressional vector. Here a horizontal offset rate of 3.3mm/yr (for the Wellington Fault) was determined using offset Ohakean terrace rises. The most northern region lies between the Tutaekuri River and Napier-Taupo Highway is a zone of normal strike-slip faulting with a combined horizontal offset rate of 18mm/yr for the Wellington, Ruahine and Te Waka Faults. These regions correspond to proposed rupture segments for both Wellington and Ruahine Faults. This study provides a record of at least 12 Ms >6.5 earthquake events recorded on the Wellington Fault in the Kahuki-Dannevirke district, 9 of which occurred in the last 30,000 years. This is the longest record of earthquake events recorded within fault trenches in New Zealand. The last earthquake on the Wellington Fault took place c. 300 years ago between Kahuki and Dannevirke. The largest single offset found in the Kahuki-Dannevirke area is estimated to have been displaced by 12m horizontally and 1.8m vertically. The estimated magnitude for an earthquake occurring in this region is between Ms 7.4 and 7.8. An earthquake of this magnitude would cause major destruction to all nearby engineering structures and to buildings in the nearby cities of Palmerston North, Napier and Hastings. Earthquakes of this size are estimated to occur every c. 300 years for the Kahuki-Dannevirke area, every 300 to 500 years for the Ohara Depression and every 1000 years for the region between the Tutaekuri River and the Napier-Taupo Highway. Similar studies were conducted along the Ruahine Fault trace between the Ohara Depression and the Napier-Taupo Highway. Seismic activity in this area is estimated to produce a Ms 7.4 to 7.5 magnitude earthquake every 400 to 500 years. Horizontal offset is expected to be in the range of 3 to 5.5m. Dates for the last earthquake on the Ruahine Fault have not been determined but it is possible that there have been up to 4 earthquakes on this fault since 1850 yrs B.P. The Wellington and Ruahine Faults pass mainly through farmland, areas of forestry and the southern Ruahine Range. When an earthquake rupture event occurs it is possible that most farmhouses will escape major damage with little loss of life, providing they are not built on the fault or in the path of any possible landslides. However major disruption is to be expected to any engineering works close to the faults. Landslides may occur on over-steep slopes in and near the axial ranges and some major rivers may be dammed as a result. The larger magnitude earthquakes will produce severe shaking in the cities of Palmerston North, Napier and Hastings where substantial damage can be expected to occur, especially to those buildings that are built on reclaimed land or on alluvial soils prone to liquefaction.

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  • The role of career development in relation to the developmental contextual position of young people in New Zealand : considerations for policy development and career services in New Zealand secondary schools : thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Education

    McIntyre, Diana J (1998)

    Doctoral thesis
    Massey University

    This is a study of young peoples' career development needs and awareness and the relationship to personal development at the interface of school provision and wider economic, political and educational change that impinge on those relationships. It is theoretically embedded within the developmental contextual position of adolescent development, but much of the study is concerned with generating a comprehensive data base to inform policy development and practice considerations in careers assistance in New Zealand secondary schools. It begins, therefore, with an overview of the analytical framework of developmental contextualism, and goes on to explore more fully the dimensions presumed to be operating in relation to the career development of New Zealand youth. In doing so, it contributes a multidisciplinarian perspective, the essence of which it is argued, is an integral and necessary consideration in the provision of a developmentally appropriate and socially accountable approach to careers services in secondary schools. An examination of senior secondary school students' career development characteristics and experiences to which schools are in a position to respond forms the central empirical study of the latter part of this thesis. School careers staff, parents' and students' believed that schools were important environments for young people's career exploration and development and that an integrated, comprehensive careers service was an acceptable responsibility of secondary schooling. The careers information bases in schools were considered to be well resourced. Other dimensions, including career education, career advice and career counselling were nominated the most crucial areas needed for improvement. Limited opportunity for professional development and training in careers work was considered by staff to be the greatest barrier toward the provision of developmentally appropriate careers assistance. Other barriers included limited time allocation for careers work, low status in the school and unclear specifications regarding the role of careers staff and career services. Parents did not feel adequately informed about the nature and role of careers assistance in schools and this was considered a hindrance toward constructive involvement with their childrens career development. For the majority of students concern around career-related issues represented the source of considerable anxiety in their life. Careers assistance was highly valued by these young people, with most expressing concern about access to good quality careers advice and careers counselling. Limited access to specialised assistance at the personal level was reflected by students self reports on measures of career development and personal coping resources. Generally, the young people reported that they had not engaged adequately in appropriate career planning activities; had few 'useful' career exploration experiences; possessed insufficient knowledge about the nature and requirements of the world of work or occupations; and were not particularly knowledgeable about what to consider in making career-related (including education, training and work) decisions. Statistically significant relationships were found between scores on indices of career development and scores on a measure of how students coped with career-related concerns. While most young people approached career problems constructively, those students who were less likely to have engaged in useful planning and exploration and who had limited knowledge of the world of work generally were more likely to approach career development concerns non-productively, such as worrying about what might happen or closing oneself off from the problem. Perhaps the most salient theme to emerge in this thesis is the conviction that the career development of young people is a social as well as a personal process. Both the individual and society have much to gain from the young person's capacity for realism and purpose concerning school and post-school pathways and ultimately in the possession of a beginning repertoire of personal resources to manage career transitions in future journeys during their adult years. Ultimately, the complex interaction of individuals and society in relation to career pathways demand school-based career services which are clearly defined in policy, operationalised in official documentation, adequately resourced in relation to personnel and training and properly integrated alongside existing school practices.

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  • Malignant lymphomas in sheep : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at Massey University

    Johnstone, Alastair Campbell (1974)

    Doctoral thesis
    Massey University

    Malignant lymphoma is the general term applied to any neoplastic disorder of lymphoid tissue, including Hodgkin's disease and reticulum cell sarcoma. This group of neoplasms are among the most commonly occurring spontaneous neoplasms of sheep in New Zealand, being exceeded in frequency only by carcinomas of the small intestine and primary neoplasms of the liver. It has not been established whether malignant lymphoma is of sporadic or enzootic occurrence in this country, but from limited epidemiological observations in which on two occasions the disease was seen in two animals from the same property, it is possible that the latter distribution occurs. This and most other series indicate that mature sheep are most frequently affected but the disease does occur in younger sheep and lambs. A study has been made of the pathology of ovine malignant lymphoma, based on 22 cases, most of which were collected from slaughter-houses and histological material from a further 18 cases filed previously at this laboratory. In nearly all cases nodular or diffuse lesions, consisting of accumulations of invasive neoplastic cells of lymphoid origin, were distributed widely throughout the body. Gross evidence of tumour in the lymph nodes was present in all except three cases of the disease. This involvement was usually multiple, with many of the carcass and visceral lymph nodes containing tumours. The spleen contained neoplastic lesions in 73 per cent. of the cases examined. Of the non-lymphoid organs affected by malignant lymphoma, the liver, kidney, bone marrow, heart, small intestine and abomasum predominated. Of the 40 cases examined, 37 were classified as lymphosarcomas and three as reticulum cell sarcomas. The degree of cellular differentiation in the lymphosarcomas varied from primitive lymphoblastoid to well differentiated lymphocytic cell types, with the less differentiated forms being more common. Some nuclear and cytoplasmic abnormalities which have previously been described as being non-specific in other types of neoplasms were seen in specimens from 10 cases which were examined with an electron microscope. Support for the hypothesis that "malignant lymphoma of sheep is transmissible" was sought by attempts to experimentally transmit this disease to lambs using intraperitoneal injections of cell-free tumour extracts during gestation or within 12 hr of birth. To date none of these sheep, which are only three years old, have developed overt neoplasia but 20 of them have developed elevated numbers of circulating lymphocytes. This has persisted for periods of two years or more and there is evidence to indicate that this should be interpreted as a preclinical phase of malignant lymphoma. To investigate an hypothesis that malignant lymphoma of sheep is due to infection by an oncorna virus, electron microscopic examinations were made on specimens from fresh tumour as well as on preparations from tissue cultures which had been inoculated with various ovine lymphoid tumour homogenates. These studies were inconclusive and it was not until cultures of phytohaemagglutinin-stimulated lymphocytes derived from the sheep with experimentally transmitted lymphocytosis were examined that virus-like particles, consistent with the morphology of "type-A" oncorna viruses could be demonstrated. They were present in membrane-limited vacuoles and cytoplasm of these cells and less frequently extra-cellularly in the five experimentally inoculated sheep examined but were not present in any of the lymphocytes from an equal number of control sheep. Lymphocyte cultures from 15 of the experimentally inoculated sheep showed sensitization to antigens in ovine malignant lymphoma homogenates when tested by a macrophage migration inhibition test. This test also demonstrated the presence of common tumour specific antigens in five of the six tumour extracts used either for sheep inoculations or in testing for macrophage inhibitory factor production. In an attempt to accelerate the development of overt neoplasia in three of the experimentally inoculated animals showing a persistent lymphocytosis, they were given a combined course of the immunosuppressive agents azathioprine and horse anti-sheep lymphocyte globulin. This resulted in a profound fall in circulating lymphocytes and while the cell mediated immunity was suppressed, as judged by the survival of skin allografts, macrophage migration inhibition in response to tumour antigens was not significantly altered in two of the three animals under treatment. A close relationship was demonstrated in the experimentally inoculated sheep between the occurrence of lymphocytosis, the development of tumour specific cell mediated immunity and the presence of virus-like particles in phytohaemagglutinin-stimulated lymphocytes. This evidence combined with the demonstration of common apparently tumour specific antigens in malignant lymphoma extracts used in these studies provides strong support for the hypothesis"that this disease of sheep is transmissible and is most probably due to an infection with an oncogenic virus". The exploitation of the sheep model described is of potential value for the comparative study of preneoplastic events in the general field of cancer research.

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  • Infant crying : mothers' perceptions and affective reactions : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Education at Massey University

    Brennan, Michael Charles (1985)

    Doctoral thesis
    Massey University

    Two studies were conducted in order to examine three major issues arising from recent studies of mothers' reactions to their crying infants. These issues, which arise in connection with the Aversive Stimulus Model of crying, relate to (a) the relationships between cry characteristics and mothers' affective reactions to crying, (b) the variability of cry characteristics of individual infants, and (c) the influence of context on mothers' reactions to their infants' crying. Resting on the premise that the semantic differential is an appropriate technique for addressing these issues. Study A examined the relationships between three sets of semantic differential scales. These were the scales reported by Brennan and Kirkland (1983), which represent three dimensions labelled Affect, Potency, and Evaluation; the scales reported by Zeskind and Lester (1978); and the scales reported by Mehrabian and Russell (1974a), which represent three dimensions of emotion labelled Pleasantness/Unpleasantness, Degree of Arousal, and Dominance/Submissiveness. A combined factor analysis of cry ratings on these scales uncovered the factor structure of the Brennan and Kirkland scales and of the Mehrabian and Russell scales. The factor representing the Brennan and Kirkland Affect scales also represented both the Zeskind and Lester scales and the Mehrabian and Russell Pleasantness/Unpleasantness scales. The Brennan and Kirkland scales were found to effectively discriminate between perceptually different cry sounds. The Mehrabian and Russell scales, however, were found to be lacking in face validity and therefore unsuitable for use with cry sounds. Study B examined the perceptions and affective reactions of mothers listening to their own infants' cries, in two situations - in the home as the crying occurred, and in an experimental situation involving tape-recorded cry samples. The results indicate that: (a) mothers affective reactions to cries did not simply depend upon the aversiveness of the cry sounds, (b) mothers' affective reactions to cries were strongly associated with their attributions regarding the causes and consequences of the cries, (c) cries from the same infant and cries from different infants varied considerably with respect to their perceived characteristics and the types of affective reactions they evoked, and (d) ratings of the tape-recorded cry samples tended to over-emphasise the relationships between cry characteristics and mothers' affective reactions, and to under-represent the extent to which negative affective reactions were experienced by the mothers in the home situation. Several suggestions were made for future studies. These included the adoption of an individualised approach to study: (a) the cry repertoires of individual infants, (b) the types and patterns of affective reactions experienced by individual mothers, (c) mothers' attributions regarding to their own feelings and their infants' behaviors, and (d) the relationships between mothers perceptions, attributions, affective reactions, and actual caregiving behaviors.

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  • Quantitative genetics of prostrateness and other related attributes in red clover (Trifolium pratense L.) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Breeding and Genetics, Department of Plant Genetics, Massey University, New Zealand

    Mirzaie-Nodoushan, Hossein (1993)

    Doctoral thesis
    Massey University

    Three major experiments were conducted to investigate quantitative genetic aspects of prostrateness and related attributes in red clover (Trifolium pratense L.) during the years 1991-1993. These were done on several red clover genotypes with prostrate growth habit, nodal rooting ability, and early flowering characteristics, together with several other genotypes from semierect and erect types. Three types of experiments were carried out: 1)Since genotype environment interaction is believed to be ubiquitous in affecting the performance of plants, a series of experiments were carried out in order to get general information on a range of red clover germplasm representative of the three distinct types of red clover. Twelve genotypes (four per type) were studied in a randomized complete block design with three replications at two sites for two successive years. Several techniques of univariate and multivariate analysis were applied in order to quantify and qualify the magnitude and pattern of the possible genotype-environment interaction effects. Phenotypic and genotypic correlation values were estimated for each year and type separately as well as for the whole data set in genotype-environment interaction experiment. As a result of GE interaction analysis, a large amount of genetic variation was found in the genotypes examined. Several attributes presented significant first and second order interaction effects. Multivariate discriminant analysis based on these effects revealed discriminant scores by which the contribution and importance of each attribute in the response of genotypes examined in the environments was studied. Cluster analysis revealed that each of the three red clover types have their own particular responses to the environment effect. Phenotypic and genotypic correlation patterns were different from year to year and type to type. Prostrate growth habit reduced dry matter yield through significant negative correlation with yield components. 2) One accession from each of the two extreme types, erect and prostrate, were examined using a hierarchical mating design to investigate their genetic structure and to obtain more detailed genetic information on a narrower germplasm. Nine random plants from each type were cloned and used as male parent. Each male parent was crossed to six different random plants as female parents, three from the same population and three from opposite population. In other words four sets of crosses, two intra- and two inter-population sets, were made. To evaluate the 108 progeny families produced, male groups were divided into six sets, each containing three male groups from the same type. Each set was examined in a randomized complete block design with three replications. Various genetic parameters including genetic variance components and heritability of several morphological attributes were estimated. The two plant populations examined by the mating design, presented different patterns of genetic variation. Although the prostrate population did not have much genetic variation, its additive genetic variance components were of more importance than dominant components. However, in the erect population, dominance components of variance were more important than additive. In inter-population crosses, additive components were more important than dominance components. Stem length, number of internodes, number of branches, and plant diameter presented high level of heterosis. Number of stems, plant height, and stem thickness presented fairly high hybrid depression (negative heterosis). Heritability broad sense and narrow sense were estimated in genotype-environment interaction experiment and hierarchical mating design. Heritability values in GE interaction experiment were different from the heritability broad sense values in hierarchical mating design for most of the attributes, indicating the influence of GE interaction effect. This difference was not noticeable in prostrateness. Heritability narrow sense estimated in hierarchical mating design varied from intra- to inter-population crosses. 3) Three sets of generation mean analysis were carried out to obtain the most detailed genetic information including function of genes, and number of genes controlling the attributes. To achieve these, three pairs of parent plants were used (one erect and one prostrate in each pair) to produce F1, F2, Bc1, and Bc2. Several attributes which were distinct enough in the two types so that it could be assumed that parent populations were nearly homozygous in opposite directions, were studied in these crosses. Three, six, and the best parsimonious models were presented for the studied attributes. Prostrateness and stem thickness were partially to completely dominant over erectness and stem thinness. Small leaf size was over-dominant over large leaf size. There were strong evidences for additive x additive non-allelic interaction for stem thickness, additive x dominance interaction for leaf size, and dominance x dominance interaction for prostrateness and leaf size. Nodal rooting ability, prostrateness, and stem thickness seemed to be controlled by a low number of genes, whereas leaf size seemed to be controlled by several genes.

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  • A comparative study of phosphofructokinase and tagatose 6-phosphate kinase from streptococcus lactis : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biochemistry at Massey University

    Fordyce, Alison Mary (1982)

    Doctoral thesis
    Massey University

    In the lactic streptococci glucose is metabolised to lactic acid via the Embden-Meyerhof-Parnas (EMP) pathway. Metabolism of lactose and galactose in these organisms involves participation of the D-tagatose 6-phosphate pathway in which galactose 6-phosphate is metabolised to triose phosphates via tagatose derivatives. Phosphofructokinase (ATP : D-fructose 6-phosphate 1-phosphotransferase, E.C. 2.7.1.11) catalyses the ATP-dependent phosphorylation of fructose 6-phosphate in the EMP pathway. The analogous reaction in the tagatose 6-phosphate pathway, phosphorylation of tagatose 6-phosphate with ATP, is catalysed by a specific enzyme, tagatose 6-phosphate kinase. While phosphofructokinase (PFK) is known to be a major regulatory enzyme in carbohydrate metabolism in most organisms, little is known of the regulatory properties of tagatose 6-phosphate kinase (T6PK). PFK and T6PK were purified from Streptococcus lactis C10 PFK was purified to homogeneity (364-fold purification) by affinity chromatography on Blue-dextran-Sepharose. Unlike PFK, T6PK did not bind to Blue-dextran-Sepharose : a 136-fold purification was achieved using ammonium sulphate fractionation, gel filtration, and ion exchange chromatography. A study of some of the properties of PFK and T6PK from S. lactis C10 showed that these two enzymes are distinct proteins with different physical and kinetic characteristics. S. lactis PFK is a tetramer (MW 145,000 daltons) of identical subunits of molecular weight 33,500 daltons. It therefore appears structurally similar to other bacterial PFKs. T6PK from S. lactis has a molecular weight of approximately 114,000 daltons, a value similar to that of Staphylococcus aureus T6PK which is a dimer. S. lactis PFK exhibited the co-operative binding of F6P and inhibition by high concentrations of ATP relative to F6P which is typical of most bacterial and mammalian PFKs. F6P0.5. and Km (MgATP) values were 0.28 mM and 0.18 mM respectively. ADP stimulated PFK activity, shifting the sigmoidal saturation curve to a more hyperbolic form, with a corresponding decrease in nH. Ammonium and potassium ions also activated PFK, while activity was inhibited by AMP, PEP, FBP, T6P and inorganic phosphate. In contrast to PFK, T6PK showed no co-operative binding of sugar phosphate substrate and was less sensitive than PFK to ATP inhibition. Km values for T6P and MgATP were 0.16 mM and 0.4 mM respectively. Apart from ammonium and potassium ions, no activators of T6PK were found. Activity was inhibited by ADP, PEP, and FBP. PFK and T6PK could catalyse phosphorylation of both F6P and T6P although the enzymes showed a much greater affinity for their natural substrate. Maximum velocities attained were higher with the natural substrate than when the other sugar phosphate was used as substrate. Both enzymes showed similar pH optima and divalent cation requirement. Levels of PFK, T6PK, and Galactokinase (Gal K), enzymes of the Embden-Meyerhof-Parnas, Tagatose 6-phosphate, and Leloir pathways respectively, were measured in strains of S. lactis, S. cremoris, S. diacetylactis and S. faecalis grown on different sugars. Growth on lactose and galactose induced increased levels of T6PK and Gal K activity, galactose generally inducing higher levels of T6PK than lactose. In most strains, addition of glucose to media containing lactose or galactose resulted in lowered activities of Gal K, comparable to those in glucose-grown cells. In contrast, T6PK activity was generally not suppressed by growth on glucose plus lactose, while in growth on glucose plus galactose, T6PK activity was approximately 50% of the activity in cells grown on glucose alone. PFK activity was generally unaffected by the sugar in the growth medium. In spite of changes in specific activities of PFK and T6PK throughout the growth period of S. lactis, the ratio of PFK : T6PK remained fairly constant. The properties of S. lactis PFK and T6PK are compared to those of these enzymes in other bacteria, and the possible role of T6PK in regulation of carbohydrate metabolism in S. lactis is discussed.

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  • The life history strategy of Carex pumila Thunb. (Cyperaceae), a rhizomatous perennial pioneer species on the sand plains of the dune system of coastal Manawatu : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Botany

    Burgess, Robert Edward (1984)

    Doctoral thesis
    Massey University

    The life history strategy of Carex pumila Thunb. (Cyperaceae), a major colonist of raw moist sand on the sand plains of coastal Manawatu, New Zealand, is outlined. By virtue of the continuous formation of sand plains, sites suitable for colonization are a permanent feature of this habitat and vegetation of increasing seral maturity is represented at any one time across a series of adjoining deflation hollows and low dunes. It is proposed that the species is an r-strategist well suited to exposure, nutrient stress and seasonal flooding. Amelioration of these conditions by deliberate perturbation treatments resulted in this seral species responding in a way that ultimately lead to its more rapid demise. The species has a rhizomatous perennial growth habit. Tne modular construction of its rhizome system is described for the first time. Similarly, the occurrence of both long and short sympodial rhizome branches and of large-diameter sinker roots have not been previously described in the literature on this species. Its floral development appears to be environmentally cued. Emergence of inflorescences occurrs in early October. Maximum size of dissemules is obtained by early January. Subsequently seeds are shed and the shoots bearing them die. The species is essentially allogamous, although in a laboratory experiment, it was found to be partially self-compatible. Self-pollination must be expected in the field since neighbouring shoots are likely to be part of the same genet. Field studies are reported in which the performance of Carex pumila was monitored, firstly at sites of increasing seral maturity both in space and in time, and secondly in response to perturbation treatments. Populations showed a pattern of development that included a juvenile phase of rhizome expansion, an adolescent phase of increasing shoot density, a mature phase in which a proportion of the shoots were reproductive, and a senile phase of diminished growth and seed production. Phasic development was more protracted on the more stressed and more exposed sites. Other species more rapidly filled the space made available by the death and decay of Carex pumila shoots, than the colonist itself. As a pioneer, the species is doomed to extinction on the sites it colonizes. In a perturbation experiment, the sward mass of the total vegetation per unit area was increased at all sites by nitrogen fertilizer, applied as ammonium ions at a rate of 50 kg N / ha. Where the Carex pumila population was in a senile phase in an old deflation hollow, the increase was made mainly by other species. In younger populations on a low dune, the density of shoots and expanding buds of Carex pumila were markedly increased by the fertilizer treatment. Associated with this, a significant increase occurred in the proportion of the total dry weight of vegetative branches in rhizomes and in green leaves. A nitrogen limitation to seed yeild was indicated at the older low dune site. Here nitrogen fertilizer addition increased seed output per unit area by increasing both seed number per culm and seed size. By contrast on the younger low dune site, seed output per unit area was unchanged by the perturbation. In this population, reallocation of resources within fertile shoots, which was seen as an increased number of seeds per culm, was offset however by a reduction in fertile shoot density. Seed reproductive effort varied between 0 and 16% of total biomass, whereas rhizome allocation was more variable; up to 100% of biomass where the species was invading an embryonic deflation hollow. As a proportion of the biomass of fertile shoots alone, seed reproductive effort estimates of up to 32% were obtained. The post-anthesis photosynthetic contribution of female spikes to final seed weight was estimated at 26%, in a growth room experiment. This estimate is considered conservative given that final seed weight was not significantly reduced by defoliation and shading of the culm. Thus, the allocation of biomass to seeds cannot be considered a drain on the carbon resources of the plant that might otherwise be allocated to growth or some other plant function. Total nitrogen concentrations were dissimilar in different plant parts and, for comparable organs, between populations of different ages. Thus, allocation patterns to component parts based on dry weight and total nitrogen were different. Given that nitrogen was seen to be limiting growth in this seral habitat, the allocation of this resource is likely to be of greater significance in the evolution of life history strategies than is that of dry weight.

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  • Studies of sap-transmissable viruses of flowering cherries : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy at MasseyUniversity

    Everett, Kerry-Rae (1993)

    Doctoral thesis
    Massey University

    Six sap-transmitted viruses were identified during a study of 434 flowering cherry trees (Prunus serrulata Lindl. sensu lato) in the North Island of New Zealand. These included Prunus necrotic ringspot ilarvirus strain G (PNRSV -G), apple mosaic ilarvirus (ApMV), flowering cherry virus B (FCVB), strawberry latent ringspot virus (SLRV), prune dwarf ilarvirus (PDV) and flowering cherry virus I (FCVI). Of these, ApMV, FCVB, SLRV and FCVI were new records for this host. FCVB and FCVI are newly described viruses. The most common virus was PNRSV -G (30.6% ); the other viruses ranged in incidence from 1 0.2% (FCVB) to 0.5% (PDV). A further nine viruses were also detected by mechanical transmission, but were not characterized in this study. Repeated sampling of 30 flowering cherry trees during late winter and early spring showed that ELISA was more sensitive for detecting PNRSV -G infection of flowering cherries than sap-transmission. Three methods for purifying PNRSV -G isolates from flowering cherry were assessed and the best method was one that used ether as a clarification agent. Yields of 5.0 mg/1 00 g of tissue were obtained. An antiserum was produced to PNRSV-G in New Zealand white rabbits which had a titre in microprecipitin tests of 1/81 92. A 338 nucleotide cDNA clone was made to PNRSV-G which hybridised to RNA-3 in Northern analysis. FCVI had a narrow host range, quasi-isometric particles of c. 26 nm diam. morphologically similar to the particles of ilarviruses, some bullet shaped particles (also characteristic of ilarviruses), four RNA species of 3550, 2800, 2000 and 1 050 nucleotides, and a coat protein of Mr 30 000. These properties indicate that FCVI has affinities with the ilarvirus group, but it differs in host range and symptoms, physical characteristics and serological properties from other members of this group. FCVB infected both monocotyledons and dicotyledons, but had a limited host range. FCVB has four RNA species of 3900, 21 50, 1 800 and 800 nucleotides (estimated from denatured dsRNA). Partially purified preparations contained isometric particles about 24nm in diameter. When purified at pH 7.5 FCVB sedimented in sucrose gradients as three UV absorbing components and virus particles appeared to be swollen. At low pH (5.0 or 6.0) or at pH 7.5 with the addition of magnesium ions, FCVB sedimented as a single predominant UV absorbing component and virus particles were not swollen. One major protein band (Mr 1 9 300) was extracted from partially purified preparations. Based on these features, it is proposed that FCVB is a new member of the bromovirus group. However, serological interrelationships were not detected with antisera to three bromoviruses, brome mosaic virus, broad bean mottle virus and cowpea chlorotic mottle virus. SLRV was isolated from flowering cherry trees in close proximity to each other in Auckland, New Zealand. The virus was not isolated from any of 390 flowering cherry trees tested from four other regions in the North Island. The virus was identified by host range, particle morphology, RNA and protein content and by serology. This is the first record of SLRV in flowering cherry. The nucleotide sequence of the 3' -terminal 2427 nucleotides of SLRV RNA-2 were determined using cDNA clones. The sequence contains a single reading frame terminating at an ochre stop codon 552 nucleotides from a 3'-terminal poly(A) tract. The N-terminal sequences of the two SLRV coat proteins determined by Edman degradation indicated that the larger 43K protein had a N-terminal Gly and the smaller 27K protein was cleaved at a Ser/Gly bond. No homologies were found in amino acid sequences or nucleotide sequences to four comoviruses or six nepoviruses suggesting that SLRV should be placed in a separate plant virus group.

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  • The design of nutritional food products for a developing country : a thesis presented in partial fulfilment of the requirements for the degree of Ph.D. in Product Development

    Edwardson, William (1974)

    Doctoral thesis
    Massey University

    A systematic methodology was developed for designing food products for the Philippines. This was the initial stage of an investigation at Massey University into the application of quantitative product development techniques to the food industry in developing countries. A study of economic, nutritional and food industry conditions indicated that Taiwan, Korea and the Philippines best satisfied the conditions necessary for the use of product development in the food industry. The Philippines was chosen for this first investigation and the quantitative study was on the selection of raw materials in formulation according to their nutritional properties. The selection of raw materials in the product development was made quantitative by use of linear programming. A linear programming model was developed to select, from a list of one hundred and seventy raw materials indigenous to the Philippines, a raw material mixture capable of satisfying twenty-six nutrient requirements as well as several interrelationships between nutrients, at a minimum cost. In the development of this model, investigations were made on the effects of altering nutritional requirements, raw material costs and compositional data and also the variety of raw materials. The linear programming model was found particularly useful for investigating the effects of changes in the nutritional requirements and in raw material costs, but rather unpredictable for changes in raw materials. The precision of the model was much greater than could be expected of the nutritional composition data. The mixture of raw materials selected to meet the Philippine nutritional requirements was developed, using the product development system, to an acceptable canned meat-loaf-type product. This product was selected, from a number of systematically generated product ideas, by a critical evaluation method, based on information on processed food eating patterns, food processing facilities and processed food distribution systems, obtained during a visit to the Philippines in 1973. This product was designed to be manufactured in large meat processing plants in the Philippines and distributed to the small stores throughout the country. The linear programming model was also used to guide the design of a food product enriched with chemical nutrients and capable of rapid introduction to Philippine diets to supplement the basic rice meal. The linear programming technique provided quantitative data for evaluation of the feasibility of enrichment with various types of food materials and chemical nutrients for the cost of various levels of enrichment and for design of product formulations, allowing for nutrient losses during processing. A coconut bun with nutrient enriched filling was developed. This product could be manufactured in the many bakeries scattered throughout the Philippines. Chemical analysis of the two products showed reasonable agreement with calculated nutrient levels, but generally nutrient levels were below calculated levels, implying that some scaling up of nutrient requirements may be necessary for this model. The real value of the systematic methodology cannot be finally assessed until an attempt is made to implement the industrial production in the Philippines and introduce the products into the diets. This first stage, of the development of the raw material selection model has provided a basis for further work on inclusion of the other properties of the raw materials such as eating quality, so that a comprehensive model for the quantitative design of foods can be finally achieved.

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  • An evaluation of microcomputer assisted instruction for teaching word recognition to mentally retarded adults : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Education, Faculty of Education, Palmerston North, New Zealand

    Ryba, Kenneth Allan (1980)

    Doctoral thesis
    Massey University

    This study compared the utility of computer assisted instruction with more conventional interpersonal tuition for teaching word recognition skills to mentally retarded adults. A second aspect of the research was to evaluate acquisition, retention, and transfer of learning using two common methods of instruction; these were errorless discrimination (word-focus only) and paired associate learning (picture-word focus). Recognition of words was selected as the experimental task on the basis that this was a practical academic area that traditionally involves large amounts of teaching time, primarily within the realm of drill and practice procedures. The sample comprised 52 subjects who were drawn from three special education facilities in Palmerston North, New Zealand (a Special School, and two Vocational Training Centres). Subjects were screened initially on tests of visual perception and letter discrimination to ensure that they possessed requisite skills to benefit from participation in training. Pre-testing was carried out to determine whether subjects were able to recall or recognize any of the words to be taught. All subjects entering the experiment knew two or less of 16 words selected for inclusion in the training programmes. Subjects were randomly assigned to computer assisted instruction or individual tuition groups with 26 persons placed in each group. Within each group, subjects were again randomly allocated to receive errorless discrimination or paired associate modes of instruction. This 2 X 2 classification resulted in 13 subjects being placed in each subgroup. Two modules each containing eight words were used for training. Both the individual instruction and computer groups were given a total of 10 training sessions, or five sessions for each of the two modules. A modified microcomputer was interfaced with a sound-on-slide projector to provide both audio and visual instruction. Parallel teaching programmes were developed for administration by computer or individual tuition. The first programme (errorless discrimination) required subjects to select target words from a series of increasingly complex word discriminations with no picture cues provided. A second teaching method (paired associate learning) involved the pairing of pictures and words. Subjects were instructed to select target words from a list of printed items that matched referent photographs. Thirteen senior special education students (Teachers College Graduates) carried out the individual training while the experimenter supervised the computer based programmes. Progress in training was assessed by comparing pre- and post-test performance on Word Recognition (verbal labelling), Word Identification (pointing on cue), and Picture-Word Matching. Transfer of learning was evaluated using situational tests requiring that subjects match printed words with real life objects. Tests of retention were conducted four weeks after completion of training. A repeated measures design was used with counterbalancing to control for possible confounding effects of list order (Modules). The findings revealed that both computer assisted instruction and interpersonal tuition resulted in very similar learning outcomes with regard to acquisition, retention, and transfer of learning. No reliable differences were found between the two groups or modes of instruction in terms of training method. It was advanced that some common features of programmed instruction (e.g. active participation, self-pacing, over-learning, and immediate feedback) may have accounted for these equal gains in performance. In respect to the question of the potential utility of microprocessor technology in special education, this research points to the efficacy of computer assisted instruction for drill and tutorial practice. Specifically, the computer provides a highly structured learning experience that has the potential to assist retarded learners in organising input materials. Evidence from this study suggests that computer related learning environments give the adult learner considerably more control of the teaching situation, and provide consistent reinforcement that is not so readily administered through conventional forms of instruction. Finally, it was proposed that the relatively impersonal, though highly interactive, nature of the computer may avoid the triggering of perceptions of failure that can impede performance of handicapped learners. This dissertation is dedicated to my wife, Beth, whose understanding and support provided me with the encouragement to complete this work.

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