Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 47-49). / xvi, 49 leaves, bound ill. (some col.) 29 cm

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Thesis (Ph.D.)--University of Wollongong, 2003. / Typescript. Bibliographical references: leaf 261-284.

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Investigations were made of the association among megagametogenesis, pollen morphology, and seed production in two irradiated apple varieties, Golden Delicious and McIntosh, and in two years, 1964 and 1965. In each year eight to ten clones of each variety were selected on the basis of low, medium, and high pollen abortion. Untreated and treated Golden Delicious and McIntosh clones with normal pollen production, approximately 90% and 50% respectively, had the highest proportion of embryo sacs at the differentiated 8-nucleate stage, and the smallest proportion of embryo sacs at the 2- and 4-nucleate stages. Irradiated clones with the least normal pollen had the highest proportion of immature 2- and 4-nucleate embryo sacs. With both varieties and in both years reduced pollen fertility was positively correlated with retarded embryo sac development. Check clones with high pollen fertility had the highest number of developed seeds per fruit and irradiated clones with reduced pollen fertility had the smallest number of developed seeds per fruit. The number of developed seeds per fruit was positively correlated with the proportion of mature 8-nucleate embryo sacs. The reduction in seed numbers in irradiated apple clones with reduced pollen fertility may be explained, in part, by retarded embryo sac development. / Land and Food Systems, Faculty of / Graduate

The ability of mammalian cells to locomote is important in a variety of normal and pathological processes. Previous work has suggested that low doses of x-irradiation may perturb cell motility, a finding that may have important consequences in embryogenesis, cancer metastasis, and immune response. This thesis has sought to study in more detail the effect of radiation on mammalian cell motility. Work performed in other laboratories used the colloidal gold assay and time lapse cinemicroscopy to study x-irradiation induced changes to 3T3 fibroblast motility in tissue culture. These studies were repeated here, with qualitative results similar to those reported earlier. However, these methods were not amenable to a detailed quantitative analysis. For this, spatial and temporal information on the motility and dynamic morphology of a large number of cells is required. Such a task would be impossible to perform manually, thus an automated microscope system was developed that used a computer-driven precision stage and a solid state optical sensor to track individual cells in tissue culture. Information on motility and morphology was concurrently extracted from many cells. As part of the thesis, several techniques were developed to analyze and display these data, and to correlate motility and morphology observations. These techniques were directed at preserving the actual process of 3T3 cell motility, and parameters were measured to quantify the short term persistence of cell movement (on a time scale of 0.5 to 2 hours), and the long term persistence of cells in maintaining certain characteristic behaviour (on a time scale of 3 to 12 hours). The response of 3T3 fibroblasts to x-irradiation was characterized by a number of parameters. The population average cell speed was measured following treatment, and a dose response and time response was determined in the range of 1.5 Gy. Other motility parameters indicate that the normal process of cell motility, evidenced by a series of motile segments, was disrupted by x-rays. This was thought to reflect perturbation to the control mechanisms of cell motility. The morphology of 3T3 cells stained with Coomassie blue was examined in an effort to correlate the observed motility changes with changes in the fixed cell morphology. This stain is a general structural protein stain with higher affinity toward microfilaments. High doses of x-rays were required to produce significant perturbation to cell morphology, and in the dose regime of interest, the morphology of irradiated cells was not identifiably different from control. Of note is that it was the well spread, quiescent cells that seemed least perturbed by large doses of irradiation. In summary, x-rays apparently disrupt the normal process of cell motility. Several lines of evidence suggest that actively migrating cells are the most perturbed by irradiation. This work has developed techniques to quantify cell motility in a meaningful way, and to characterize the x-ray induced perturbations. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The radiosity method of radiant interchange analysis of enclosures was used to predict the intensity and the uniformity of thermal radiation within a controlled environment chamber. The chamber was designed for testing the effects of infrared radiation on young broilers. The walls of the chamber were assumed to be grey and separated by a radiatively non-participating medium. Also the black globe thermometer method was used to calculate the incident radiation at different locations in the chamber. Then, the results obtained by the two mentioned methods, were compared. Two separate experiments were designed for different purposes. The first experiment was to study the influence of infrared radiation on poultry. In this experiment, two levels of radiation were tested and the results were compared to those obtained by use of a conventional heat lamp brooding system. The second experiment was to compare a controlled temperature, warm air brooding system, to a conventional heat lamp brooding system. The relative effects in both sets of experiments were measured by use of the weekly growth rate index. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

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