673 results for 1970, Doctoral

  • 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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  • 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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  • 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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  • 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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  • 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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  • Some aspects of meiosis in normal and Robertsonian translocation-carrying rams : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University

    Chapman, Helen Margaret (1974)

    Doctoral thesis
    Massey University

    SOME ASPECTS OF MEIOSIS IN NORMAL AND ROBERTSONIAN TRANSLOCATION-CARRYING RAMS A study was made of the meiotic chromosomes in air-dried preparations from 35 genitally sound rams (Ovis aries). The quantity and quality of dividing cells were best when testicular material was obtained by castration under local anaesthesia from rams during their breeding season. Sodium tri-citrate solution was used as hypotonic treatment and the cells were fixed in suspension with glacial acetic acid and absolute alcohel plus a trace of chloreform. Slides were stained either with aceto-orcein or with Giemsa for a "C-banding" technique. Fourteen of the rams bad a normal mitotie karyetype (54,xy) and the remainder were heterozygous or homozygous carriers of a Massey I, Massey II or Massey III Robertsonian translocation and had the following mitotic karyotypes: 53,xy,t(5q26q); 52,xy, t(5q26q) t(5q26q); 53,xy,t(8q11q); 53,xy,t(7q25q); 52,xy, t(7q25q) t (7q25q). One ram was heterozygous for both the Massey I and Massey III Robertsonian translocations. Analysis of primary spermatocyte cells showed that a modal number of 27 chromosomal elements was present in normal rams, while in both heterozygous and homozygous Robertsonian translocation-carriers, a modal number of 26 chromosomal elements was recorded. Heterozygous carriers of the three types of Robertsonian translocations, which involved non-homologous chromosomes, were characterized by the presence of a trivalent in cells at the diplotene, diakinesis and metaphase I stages. The modal number of chromosomal elements was recorded in over 80 per cent of the cells at diakinesis and metaphase I in the heterozygous and normal rams while over 77 per cent of the cells in the Massey I homozygote and 90 per cent of the cells in the Massey III homozygote had modal counts. An association between the sex bivalent and a small autosomal bivalent was recorded in 7.5 per cent of the diakinesis-metaphase I cells from normal rams and in between 3.4 and 4.7 per cent of the cells from the translocation-carrying rams. Separation of the sex chromosomes was observed in 0.5 to 1.5 per cent of the diakinesis-metaphase I cells in both Robertsonian translocation-carrying and normal rams. However no evidence at metaphase II of the sex chromosome aneuploidy expected if the two univalents disjoined at random at first anaphase whs observed. Eighty seven metaphase II figures from normal rams and 1,146 metaphase II figures from Robertsonian translocation-carrying rams were recorded. Detailed analysis of 1,131 cells showed that over 80 per cent of the non-polyploid metaphase II figures from the normal and homozygous rams had euploid chromosome arm counts. In contrast between 54 and 67 per cent of the metaphase II figures from the heterozygous rams were euploid. No hypermodal cells were recorded at metaphase II in either the normal or homozygous rams but from 4.5 to 9.2 per cent of the metaphase II cells in the three types of heterozygous ram were hypermodal. The results obtained in this thesis showed that the proportion of cells with chromosome arm counts of 29 was higher in the heterozygotes than in the normal or homozygous Robertsonian translocation-carrying rams. There were significantly greater numbers of cells with 29 chromosome arms than with 31 chromosome arms in the three heterozygote classes which suggested that chromosome loss due to lagging at first anaphase or technical manipulation, must have occurred in addition to non-disjunction. Statistically significant differences in chromosome arm distributions were shown to exist between rams which were heterozygous for a particular translocation and rams which were homozygous for the same translocation or normal rams. In addition to differences between individual rams, a significant difference between the Massey II Robertsonian translocation and the Massey I and III Robertsonian translocations occurred. Fewer balanced translocation X-bearing metaphase II cells were recorded than expected in three of the four Massey II Robertsonian translocation heterozygotes. Non-translocation bearing X and Y cells predominated at metaphase II in the three translocation types when total metaphase II counts were considered, and greater than expected numbers of X-bearing cells were found in both the euploid and aneuploid classes in the Massey III Robertsonian translocation heterozygotes. Since the majority of normal ewes mated with Robertsonian translocation heterozygous rams conceived to their first service, and because no lambs with unbalanced karyotypes associated with a Robertsonian translocation have been recorded, it is suggested that only chromosomally balanced (euploid) spermatozoa are involved in fertilization. It is further suggested that the absence of unbalanced karyotypes in progeny is explicable on the basis of a degeneration of aneuploid spermatocytes occurring prior to their maturation. The three translocations in the homozygous state behaved as normal autosomal bivalents at meiosis with regular segregation at anaphase I. It is suggested that the lowered fertility seen in matings involving heterozygous rams and heterozygous ewes cannot be attributed to any deficiencies in the spermatogenic function of the ram.

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  • Aspects of electromagnetic scattering.

    Hunter, J. D. (1970)

    Doctoral thesis
    University of Canterbury Library

    An expression for the field scattered by a perfectly conducting wedge with a deformed apex is formulated as a finite matrix equation to illustrate the application of the current density replacement technique. This technique enables the scattering from any size of body to be determined to a given accuracy after the inversion of one finite matrix, provided that the shape of the body can be derived by inwardly deforming a finite part of a body from which the scattering is known explicitly. The size of only the deformed part of the body is limited by available computational facilities. The field scattered from truncated and rounded wedges is calculated. These results not only enable the effect of edge deformation to be studied, but are also used to evaluate the accuracy of the geometrical theory of diffraction and physical optics estimates of the diffracted field. Expressions for the field scattered by a perfectly conducting wedge in the presence of transversely polarized line sources are found. These results are used with an iterative current density replacement technique to formulate expressions for the field scattered by a truncated wedge, and thus derive a secondary edge diffraction coefficient for use with the geometrical theory of diffraction. This coefficient is applicable to perfectly conducting bodies with small or large separation between edges. The increased accuracy obtainable with this coefficient, and a modification to the physical optics representation of the current density on a body with edges, are discussed.

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  • Social organisation of the Adelie Penguin, Pygoscelis adeliae.

    Spurr, E. B. (1972)

    Doctoral thesis
    University of Canterbury Library

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  • Stratospheric circulation: a narrowband filter spectrophotometer for total ozone determination.

    Basher, Reid E. (1975)

    Doctoral thesis
    University of Canterbury Library

    This thesis describes the use of ultraviolet narrowband interference filters in the spectrophotometric determination of local atmospheric total ozone burdens. An investigation of a prototype interference filter spectrophotometer shows that its total ozone measurements are in error owing to the breadth of the filters' passband skirts and to the transmittance sideband leakages of the filters. Accurate spectral transmittance measurements, extending down to transmittances of 10-7, are described and show that the leakage sidebands generally occur close to the passbands and in the near infrared spectral region. An outline of the design and construction of a new, more accurate filter spectrophotometer is given. The use of stacks of two filters at each wavelength greatly improves the narrowness of the passband skirts and significantly decreases the transmittances of the leakage sidebands. In addition a very effective sideband blocking filter is used. The considerably improved performance of this new spectrophotometer is confirmed by the results of a direct comparison of the instrument with a standard Dobson prism spectrophotometer. A study is presented of the effects of filter non-uniformity, orientation, aging and temperature. This enables the establishment of criteria in these regards for accurate total ozone-measurement. A similar study is made of the instrument's photomultiplier detector. The effects of the filters' finite bandwidths are analysed by a numerical simulation of the spectral characteristics of the whole measurement process. The theory involved is given. Calculations show that double stacked filters perform considerably better than single filters. Over the usual operating ranges of airmass and total ozone, the error in the total ozone measurement due to the filter bandwidth effect, is found to be about ±1.0% for the doubled-filter instrument. Corrections for the error are tabulated.

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  • Studies on Vesicular-arbuscular mycorrhizae in Allium species.

    Mohamed, Mokhtar bin Mohamed Yusoff (1977)

    Doctoral thesis
    University of Canterbury Library

    This study is divided into three main parts. The first is an investigation of the effect of vesicular - arbuscular mycorrhizal fungus Endogone on the growth of Allium cepa and Allium porrum. Onion and leek seedlings were inoculated with Endogone spores and the progression of the mycorrhizal colonisation followed. The effects of the mycorrhizal association on the plants were determined by measuring the shoot and root dry weight, number of roots produced and height of plant. Plants in which mycorrhiza became well established showed significantly enhanced growth rates. The second part of this study was an investigation on the possible role of vesicular - arbuscular mycorrhiza in the resistance of onion plants to two soil – borne fungal diseases, namely basal root rot, caused by Fusarium oxysporum var. cepa and pink rot, caused by Pyrenochaeta terrestris. A marked resistance to these pathogens was found in plants with a well developed mycorrhizal association. An increased phosphate nutrition of the plants provided by applying CaHPO4.2H2O to soil media was found to be insufficient to afford disease resistance. The third part of this investigation was an attempt to culture Endogone in agar media in the presence of A. cepa, using low phosphate concentrations of CaHPO4.2H2O, calcium phytate, sodium phytate or lnositol. Germination of Endogone spores in the same phosphate sources containing the vitamins nicotinic acid and thiamine HCI was also investigated. Calcium phytate elicited the best response in the culturing of Endogone in agar media, while the vitamins, used together and in combination with calcium phytate gave the highest percentage germination of Endogone spores. An ultrastructural study of vesicular – arbuscular mycorrhizal development was carried out to determine the spatial relationships between the endophyte and host cells. Difficulty was encountered with the fragility of the root tissue.

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  • Contributions to guided wave theory.

    Ng, Fook Loy (1972)

    Doctoral thesis
    University of Canterbury Library

    There are many forms of structure for the guiding of electromagnetic waves. A review of these forms is given by Barlow (1964). He describes the well established parallel-wire and coaxial lines, and hollow uniform waveguides. He also considers waveguides containing solid materials and gaseous plasmas, and beam and surface waveguides. This thesis is a report on investigations into the numerical computations of the propagation characteristics of three types of guiding structures namely, the hollow waveguide, dielectric loaded waveguide and the dielectric clad azimuthal surface waveguide. The numerical solution of the hollow waveguide problem is considered in Part 1. Chapter 1 contains a comprehensive review of the methods used for the solution of the waveguide problem. This complements the only presently available review, given by Davies (1972) who compares and discusses the relative merits of some current methods (finite difference, finite element, point-matching, integral formulations and conformal transformation). Some useful criteria established by Davies in his review for the comparison of methods are used in Chap. 1 (Sec. 1.3). Chapter 2 is concerned with the numerical solution of waveguides of arbitrary cross-section by the null field method which was developed by Bates (1969b). Accurate results are obtained and it is demonstrated that for shapes possessing sharp reentrant corners, the computational accuracy is improved by explicitly satisfying the edge conditions at these corners. The detailed numerical investigation provides the supporting evidence for the computational viability of the null field method. The complete point-matching method is derived from the null field method and it provides an insight into the straightforward point-matching method (Bates 1969b). Chapter 3 considers point-matching methods of solution. Results obtained using the complete point-matching method show that accuracies of about 0.1% are obtainable for waveguide cross-sections which are convex. Less accurate results are obtained for cross-sections that are strongly reentrant. The alternative point-matching method (Bates 1969b) is also briefly considered. By comparing results for a rectangular waveguide, the alternative point-matching method is shown to be more error sensitive than the complete point matching method. When the straightforward point-matching method (Yee and Audeh 1965, 1966b; Bates 1969b) was proposed and used by Yee and Audeh for waveguide problems, doubts were raised as to its universal applicability (Harrington 1965; Bates 1967, 1969b; Millar and Bates 1970; Lewin 1970) and an example of its failure was given by Davies and Nagenthiram (1971). The detailed investigations in chapter 3 show conclusively that the straightforward point-matching method does sometimes break down and give erroneous wave functions. Chapter 3 also relates the applicability of the straightforward point-matching method to the validity or otherwise of an internal Rayleigh hypothesis which is introduced; 3 and shows that the straightforward point-matching method is unlikely to produce correct results when the waveguide cross-section has reentrant parts. An extended point-matching method is next introduced in chapter 3 and is employed to obtain accurate results for some cases for which the straightforward point-matching method fails. The success of the extended point-matching method is further illustrated by the prediction of a particular mode for the ridge waveguide (Sec. 3.5.1.4) which seems to have been missed by a previous analysis (Beaubien and Wexler 1970) using a high-order finite difference method. Part 2 is concerned with the cutoff characteristics of dielectric loaded waveguides. A specialised form of a general polarization source formulation (Bates 1970) is given in Chapter 4 and is used in Chapter 5 to obtain formulas for the cutoff characteristics of a waveguide of arbitrary cross-section loaded with a circularly cylindrical dielectric tube. The significance of the derivation given in chapter 5 is that the unknown field in the dielectric is eliminated and formulas are obtained that are line integral equations for the surface current densities on the waveguide wall alone. The computational convenience of the formulas is illustrated by results for a square waveguide loaded with a dielectric rod. Confirmatory experimental results are also reported. The numerical computation of the propagation of an azimuthal surface wave is presented in Part 3. In previous analyses of the azimuthal surface wave the attenuation is assumed to be small. This assumption is generally only satisfactory for very small curvatures. An investigation without such assumptions is given in Part 3. The general external field for any circular cylindrical guiding surface is considered in chapter 6 and universal tables for the surface impedance are given. These results are used in chapter 7 to obtain the accurate dependence upon curvature of the propagation characteristics of a dielectric clad circular cylindrical guiding surface. General conclusions are drawn in Part 4 which also gives some suggestions for further research. The results of chapters 2 and 3, for the null field method and point-matching methods, are new. The formulation and results of chapter 5 (dielectric loaded waveguides) are also new, as are the derivations and results of chapters 6 and 7 (azimuthal surface wave). All the computer programs used, except for one subroutine, were written by the author, in Fortran IV with 8-byte (64 bit) words, and run on the University of Canterbury IBM 360/44 machine which has 128 Kbytes of core memory. The Bessel functions of the first and second kind used were computed from the ascending series (Abramowitz and Stegun 1965, formulas 9.1.10 and 9.1.11). The Lommel polynomials required in Part 3 were computed using the recurrence relation given in Watson (1968, sec. 9.63) and a standard. IBM subroutine (IBM System 360, Scientific Subroutine Package 1968, p.367), modified to double precision by the author, was used to generate the modified Bessel function K1. The following papers, relevant to this thesis, have been produced: Bates, R.R.T. and Ng, F.L. (1971), “Contributions to the theory of the azimuthal surface wave", Alta Frequenza, 40, 658-666. Ng, F.L. and Bates, R.R.T. (1972), “Null field method for waveguides of arbitrary cross-section”, IEEE Trans., Microwave Theory Tech., in press. Bates, R.R.T. and Ng, F.L. (1972), “Point matching computation of transverse resonances”, submitted to: Int. Jour. for Numerical Methods in Engineering. Bates, R.R.T. and Ng, F.L. (1972), “Polarization source formulation of electromagnetism and dielectric loaded waveguides”, submitted to: Froc. IEE(London).

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  • Some aspects of the productivity of Lake Grassmere, Malborough, New Zealand and its possible utilisation.

    Knight, Grant (1974)

    Doctoral thesis
    University of Canterbury Library

    The growth of Artemia salina Branchiopoda, Anostraca in the concentrating ponds of a solar salt extraction plant was investigated during 1972/63. The aim of the study was to assess the possibility of harvesting the Artemia production of the ponds. A pronounced seasonal fluctuation in Artemia density in ponds with over 20,000/m³ at the highest had a spring maximum and a later summer minimum. The spring upsurge was found to come from overwintering adults. The proportion of females carrying eggs ranged from 98% in spring down to 2% in winter but the number of eggs produced per female showed a highly significant variation with salinity (over a 30 day period 231 eggs at 100 ppt and 89 eggs at 250 ppt). By counting the number of eggs present in mature females a sharp drop was shown to occur at salinities above 200 ppt. Hatching times and the percentage of eggs laid that do not hatch were shown to be greatly influenced by salinity and temperature. At 26ºC hatching times at 30 ppt salinity and 240 ppt were 2 and 5 days respectively. However, at 240 ppt less than 5% hatched. In contrast, at 7ºC hatching times at 30 ppt and 150 ppt (max. at which eggs hatched) were 8 and 22 days respectively. It was concluded that increasing temperature reduced the inhibitory effect of higher salinity. Laboratory experiments showed that longevity of Artemia was greatest at 17ºC and decreased at 7ºC and 26ºC but life and fertility tables constructed from the data showed a much higher fertility rate at 26ºC than 17ºC (rc = 0.305 and 0.207 respectively) and it was considered that the increased at 26ºC outweighed the shorter life span when considering production of Artemia. Feeding trials using the unicellular flagellate alga Dunaliella euchlora showed that in a suspension of 4000 cells/ml adult Artemia assimilated 57% of ingested algae but as the density of algae was increased to 10,000/ml the efficiency of assimilation fell to 42%. Similar trials with juveniles (2 – 4 mm) showed a lower efficiency (54%) at 4000 cells/ml but higher (47%) at 10,000 cells/ml. Lipid content of Artemia ranged from 18.3% during the spring algal peak down to 11% in autumn. Both swimming rate and feeding efficiency were found to be significantly affected by increasing viscosity as brine concentration increased. The swimming effort was found to increase by 33.7% between 60 ppt salinity and 300 ppt. A highly significant decrease in food uptake was found over the same salinities with consumption of algal cells in laboratory experiments falling from 26.2% of that available to 21.6%. The combination of increased effort and reduced food intake was considered to be partially responsible for the reduced vigour of Artemia populations at high salinities. Experimental laboratory populations of Artemia reacted strongly when the algal growth rate in the culture was stimulated by fertilising and the addition of dried yeast. Stable populations of the equivalent of 860,000/m³ were produced in the laboratory. These were easily maintained and showed no evidence of metabolite poisoning or lack of oxygen. Production of the Artemia in the ponds showed that the maximum reached in a pond with an annual range of salinity from 111 ppt to 188 ppt (winter and summer respectively) and decreased in other ponds of higher values. Mean daily production for the 14 month sampling period was 0.4111 (g/m³)/day with a range from 1.53 (g/m³)/day in spring to 0.006 (g/m³)/day in autumn. Equivalent values for the most aline pond in the series were 0.049 (g/m³)/day, 0.24 (g/m³)/day and 0.003 (g/m³)/day respectively. The very large range of salinity, caused by saltworks production methods, were considered to be very detrimental to efficient harvesting where a continuous production of Artemia may be needed. The study of the Artemia production was supported by the determination of water chemistry in the ponds and algal production over the study period. Nutrients selected for analyses were reactive nitrate, reactive silicate and orthophosphate. Nitrate levels ranged from 0.43 g/m³ to 0.07g/m³ with a winter peak followed by a sharp spring drop and a summer low point. A similar pattern was found for orthophosphate concentrations but with a much larger range from 0.619 g/m³ in winter to trace amounts during summer. Silicate levels varied directly with salinity and no evidence of high biological consumption was found. The sediment of ponds at salinities over 150 ppt was cemented by precipitated calcium sulphate preventing development of turbidity even with strong wave action. pH of the ponds varied between 8.0 and 8.5 but the onset of high spring algal growth was accompanied by a drop in pH that could not be readily explained. It may be due to strong bacterial growth. The algae were dominated by two species, Dunaliella euchlora and D. salina. D.salina was confined to brines that were almost saturated but D.euchlora grew throughout the series. Production of algae was estimated from laboratory incubator experiments. These suggested that primary production would be highest in salinities between 100 and 200 ppt. Growth trials of algae in artificial media showed that levels of reactive phosphate below 0.01 g/m³ imposed strong restrictions on growth. An annual budget of energy loss and gain was set up taking into account primary and secondary production and losses caused by Artemia respiration, faeces and egg production. Overall, for the most productive pond an ecological efficiency for conversion of algal energy into Artemia biomass of 19.1% was found. A brief review of species of commercially cultivated shrimp was given consistent with the long-term possibility of using the Artemia production as a food, or food supplement, for growing shrimp. Conclusions reached were that the crop of Artemia in the ponds, while they are being used to manufacture salt, is too sporadic to be easily harvested. The potential productivity in a carefully managed pond may be very high. Artemia can exist over a wide range of salinities but will perform well only within a restricted range.

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  • A thyristor-controlled regulating transformer.

    Duke, R. M. (1979)

    Doctoral thesis
    University of Canterbury Library

    Based on the principle of the voltage regulating transformer, a thyristor-controlled voltage regulator which effects both magnitude and phase shift control is proposed. Two back-to-back thyristor switches per phase are required, and the device provides fast and continuously variable voltage magnitude and phase shift control at the expense of some waveform distortion. A dynamic simulation computer programme, which is based on the state-space approach, is developed. A three-phase control unit, to control the thyristor switchings on each phase, is described and the theoretical waveforms are verified by both experimental tests and digital computer studies. Consideration is also given to the harmonic content produced. Applications of the proposed thyristor-controlled regulating transform to the problems of voltage regulation, power transfer control and improvement in the transient stability of interconnected systems are also presented.

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  • From precepts to people: A study of characterisation in the novels of George Eliot

    Neutze, Diana (1979)

    Doctoral thesis
    University of Canterbury Library

    George Eliot is undoubtedly one of our most intellectual authors. A study of her methods of characterisation, of the kinds of choices her characters confront, and of the solutions offered for the various moral dilemmas discussed in the novels, reveals the basic moral and psychological assumptions she shared with her contemporaries. Thus, the tensions generated by her attempt to reconcile a belief in universal causality with a belief in the possibility of exercising the will and therefore of being morally responsible require her to emphasise the inexorability of the laws of antecedent and consequent and at the same time to retain for her characters a slight measure of freedom of choice. As nineteenth century psychology gradually freed itself of its philosophical origins, it incorporated elements from biology, neurophysiology, and sociology. George Eliot's knowledge of association psychology is revealed by her use of the theory of psychological determinism which governs the way in which her characters exhibit moral ascendancy or decline. Similarly, her emphasis on the "medium" in which a character lives relates to the mid-nineteenth century biological and sociological stress on environment and the interdependence of an organism with its medium. Lastly, the emergent evolutionary psychology which held that ancestral tendencies, once established in the nervous system, were transmittable from generation to generation, becomes a factor in two of her later works. George Eliott’s concern for the moral development of her readers and the enlargement of their sympathies is well documented in her letters. Because she believes in the possibilities of individual moral growth, the novels are concerned with moral development and decline. Characters can be placed along a moral axis according as they display or reject such qualities as sympathy, or allegiance to the past, or acceptance of duty. Unmistakably throughout all George Eliot's moral conflicts and solutions is a hierarchy of absolute values. To bridge the gap between description and evaluation, however, it is necessary to examine more specifically the aesthetic implications of George Eliot's framework of belief. Her concept of self, the tragic implications of a framework of universal causality and irreversible laws, constitute important limitations on the manipulation of plot and theme, and on the development of characters and the choices they confront.

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  • Interactive computer based music systems

    Tucker, W. H. (1977)

    Doctoral thesis
    University of Canterbury Library

    The application of digital computing techniques to music is considered herein, with particular emphasis on interactive systems. Three distinct topics are discussed: computer aids for musicians, sound synthesis, and pitch trajectory estimation. A comprehensive review of the literature pertaining to each topic is presented. An interactive "Piano Typewriter" system which permits music played on an electronic organ to be recorded for subsequent playback, display and editing is described. Two notations are incorporated - MOD (a positional notation) and TRAD (a subset of conventional notation). Particular attention is paid to the transcription of keyboard performance information for TRAD display, and its subsequent editing. Examples which illustrate the present state of the system are presented. A digital synthesiser which is implemented in dedicated hardware and which permits a wide range of sound timbres to be generated and performed interactively under computer control is described. Techniques for pitch trajectory estimation are reviewed in detail, and are assessed with respect to their suitability for wide-band musical signals. Numerical transform techniques for evaluating correlations are also reviewed. A new pitch estimation algorithm which operates in the time-domain by recognising recurring "features" of the signal waveform is described and is related analytically to autocorrelation analysis. The performance of the new algorithm is compared with that of the Gold and Rabiner parallel processing algorithm, and it is concluded that the former is more suitable for most music and speech signals.

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  • Swash zone processes: An examination of water motion and the relations between water motion and foreshore response on some mixed sand and shingle beaches, Kaikoura, New Zealand

    Kirk, R. M. (1970)

    Doctoral thesis
    University of Canterbury Library

    While much work in coastal geomorphology has been concerned with the analysis and description of morphological and sedimentological changes occurring on the sub-aerial beach face, relatively little effort has been applied to the detailed investigation of the processes responsible for the production and modification of these features. Only scattered, fragmentary observations of such fundamental properties as swash velocity, backwash velocity, flow depths and durations exist in the literature and these data have been poorly co-ordinated with other information relating to input wave parameters, grain size, slope and profile dimensions which is necessary to a complete understanding of the forces governing swash zone morphology. In an effort to bridge this gap an instrument system has been designed and constructed for the measurement of flow speeds, pressures, asymmetries, depths, levels of groundwater storage and outflow, and of flow durations. In association with the observations of these and other process factors several responses to the flow regime were also sampled. These included alterations to grain size parameters of bed sediments, transport rates of solids in the swash and backwash, vertical distributions of sediment in both swash and backwash, and changes in bed elevation. An electromechanical force-plate dynamometer was employed for the measurement of flow speed and duration and a small parallel-wire gauge sensed depth fluctuations in swash and backwash flows. The output from both of these units was recorded on a strip chart for later analysis. A total of twenty one data sets were derived in this way from four profiles located on mixed sand/shingle beaches at Kaikoura, East Coast, New Zealand. Two profile stations have steep, well sorted shingle foreshores while the other two are flatter and are composed of mixed sand and shingle. A wide range of breaker heights, periods and types is received at all four stations. More than 3,000 individual measurements of swash/backwash flow conditions were obtained from these four stations under varying wave, tide and foreshore conditions. Analysis of this and associated data relating to sediment transport indicates that the flow/sediment system of the swash zone on the study beaches is bounded approximately by current speeds of 100 to 250 cm/sec. and by grain diameters of 1.0 to 50.0 mm. Because of the high energy nature of the system and the large range of grain sizes available for transport, the conditions for initiation of motion are rapidly and frequently exceeded and particles are transported at high rates. Sorting processes are thus dependent upon the net rates of transport of individual size fractions in the flows rather than on critical selection of individual sizes from the bed. The latter situation applies only to very large particles and these are quantitatively infrequent on the study beaches. The concentration profiles of entrained sediments in the water column vary with differences in turbulent structure so that mean current speed is a poor estimator of flow sediment load. Between 50 and 95% of the sediment load in both the swash and backwash occurs in the lower one tenth of the water column so that transport is dominantly in the bedload phase. This feature is especially pronounced in the backwash. Bedload sediment motion in the swash zone occurs mainly in the form of sheet flow, though antidunes may be formed in the backwash and saltation is locally important near the swash limit. Energy levels in both the swash and backwash rise with increasing wave height and period, the backwash becoming dominant at higher energy levels. The chief determinant of the flow structures and morphological results of given flow regimes is the phase ratio of swash period to breaker period. For low values of the ratio there is little interference between incoming and outgoing flows, up to one third of the swash volume may be stored in the beach, the flow regime is dominantly tranquil, and the foreshore accretes. Circulation of sediments through the breakers is intermittent and would appear to occur mainly in rip currents. For values of the ratio near unity (transitional conditions) a scour zone is developed by the backwash owing to alterations in flow structure during downslope passage of the water and some erosion occurs, thus offsetting swash deposition to some extent. At high values of the ratio interference between incoming and outgoing flows is continual. The backwash scour zone is very wide and seaward circulation of sediments through the breaker is continuously developed. Flow turbulence and asymmetries are at maximum levels and suspended load transport accounts for a quantitatively significant proportion of total load transport. The foreshore erodes intensively. Characteristic sediment sorting processes are associated with these flow regimes. Tranquil, low energy conditions result in truncation and mixing of the finer fractions. Polymodal or bimodal size-frequency distributions may be produced by deposition at the swash limit. For higher energy flow regimes transport of whole bed size ranges occurs, though individual component fractions may move at differing net rates and in net opposite directions. Where wide ranges of sizes occur on the bed bimodal distributions are produced by backwash scour owing to selection and preferential erosion of a mid-range fraction. Owing to the retarding effect of groundwater storage all of these processes have a strong tidal aspect with maximum swash and backwash energy levels occurring some time after high water during the ebb tide phase. High rates of groundwater return to the backwash may result in significant fluidisation of bed sediments. Residual groundwater flow in the form of thin surface sheets results in the formation of rills and rhomboidal ripple marks.

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  • The genesis and development of landfall and its influence in relation to the culture of New Zealand and the Commonwealth

    Anido, David G. H. (1972)

    Doctoral thesis
    University of Canterbury Library

    All the research and development of the following dissertation has been made possible by the award of a New Zealand Commonwealth Scholarship (1970-1972) tenable at the University of Canterbury in Christchurch. The spirit in which the Scholarship is awarded is one of mutual understanding between Commonwealth countries, as a first step to better international understanding among all countries, and it is sincerely hoped that this thesis will, in some small way, contribute to the spirit of friendship and cooperation that exists between Canada and New Zealand. It is my opinion that no two Western countries have greater common interests; in peacekeeping and peacemaking; in trade and non-alignment with military blocs; in standard of living and quality of life; in relations between ethnic minorities and powerful majorities in sovereign states: and I believe that our histories have led us in comparable cultural, social, and political directions. The original goal that led me to pursue doctoral studies was to present a major comparative study of "the social and literary mythology" (ideas discussed by Northrop Frye in Fables of Identity) of Canada, New Zealand and Australia. The comparative aspect of this goal is now planned for a future book. The extensive and rich documentation of the story of New Zealand, available in the many city, provincial, university and private libraries throughout the country, has made the confines of a Ph.D. thesis hard to determine. As a result, and in order to choose a suitable and original topic, the thesis has been confined to a discussion of post-war New Zealand literature and culture as presented in the quarterly Landfall under its first editor, Charles Brasch (1947-1966). The Introduction to the thesis explains the approach towards the topic: "The Genesis and Development of Landfall and its influence in Relation to the Culture of New Zealand and the Commonwealth." The term "Commonwealth" has been alluded to so that the thesis can be regarded in terms of the future comparative study. I believe that the term "Commonwealth literature", as accepted at the Conference on Commonwealth Literature held in Leeds (9-12 September 1964); can be used for the time being as a premise for comparative study. The chapter on historic influences on Landfall is a survey of intellectual periodicals that developed out of the radical years of the Depression. A discussion of Charles Brasch and editorial policy arose from the comment by E.H. McCormick that "the periodical is best approached through a consideration of its editor".

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  • Five New Zealand poets: A bibliographical and critical account of mauscript material

    Weir, John E. (1974)

    Doctoral thesis
    University of Canterbury Library

    The primary intention of this thesis is indicated by its title: it sets out to examine and catalogue selected manuscript versions of published and unpublished poems by five New Zealand poets. Other material which is of a secondary nature in relation to the primary purpose of this study is also introduced, especially when I have regarded it as central to the development of a particular argument. This material largely consists of: - letters and other relevant prose manuscripts; - critical material existing either in manuscript or in some uncollected or ephemeral form. In all such cases, I have concluded that the material warrants preservation because of its inherent value. On those few occasions when I have drawn on familiar published material I have done so in the belief that the citations are relevant to a critical discussion arising from the manuscript sources. The Checklist of manuscript holdings does not pretend to be definitive. It merely sets out to examine certain specified manuscript collections in some detail, while making reference to a number of other important collections. These major collections are: (1) Ursula Bethell's Papers: currently in the possession of Mr, Lawrence Baigent, Christchurch. (2) Eileen Duggan's Papers: as bequeathed to the Roman Catholic Archdiocese of Wellington. (3) R.A.K. Mason's Papers: currently in the possession of his wife, Mrs. Dorothea Mason, Auckland. (4) James K. Baxter's Papers: a collection in the possession of the writer, J.E. Weir, Christchurch. (5) Alistair Campbell's Papers currently in his own possession. It will be observed that, except in the case of Baxter, the manuscript collections are those of the poets themselves. Thus they have a special importance, especially because they have not yet been sighted by any other researcher or critic. Because of the vastness of the Baxter Collection in the Hocken Library, the limitations put upon its use, and the difficulty of tracing the many other collections which exist in this country, I have decided to concentrate on my own considerable collection of his poems, correspondence and other prose. I am fully aware of the inadequacies of this bibliographical survey, but I also believe that it is not yet possible to make a comprehensive bibliographical study of the Papers of these poets. One further reservation must be made: this thesis does not aim at providing a general critical survey of the poet's work or achievement. Whatever particular conclusions are reached are presented in the course of the study itself. I am presenting as a supplement bibliographical material relating to the published writings of these five poets which forms part of a much more extensive bibliography of material relating to New Zealand Literature in general, and New Zealand poetry in particular. I have been engaged in this work for a number of years and it has now been completed.

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  • Studies on the vascular cambium

    Butterfield, B. G. (1974)

    Doctoral thesis
    University of Canterbury Library

    The nature of the vascular cambium is discussed and the length of the elements in the secondary xylem related to the division and elongation cycles of the cambial fusiform initials. Particular attention is given to the activities of the storeyed cambium. The ontogeny of the storeyed cambium is described for Hoheria angustifolia Raoul. (Malvaceae). The transition from procambium to cambium was found to take place gradually, the meristem acquiring cambial characteristics over a number of internodes, some before and some after internodal elongation had ceased. The cambium is non storeyed at the commencement of secondary growth but later develops a storeyed pattern. Developmental changes in the cambium with radial growth were studied in Aeschynomene hispida Willd. (Papilionaceae). Repeated radial longitudinal divisions in the fusiform cambial initials in this plant produce a highly developed storeyed pattern with radial growth. The frequency of these divisions decreases with increasing distance from the stem centre. The mean length of the fusiform initials decreases slightly with radial growth. Variation in the size of the fusiform initials and vessel members was also investigated in Hoberia angustifolia. Mean length of the fusiform initials was found to remain constant with increasing distance from the stem centre but a slight decrease was observed with increasing height in the tree. Mean fusiform initial width showed an increase followed by a decrease with increasing height in the tree. The significance of these results is related to the division pattern in the storeyed cambium.

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