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The research literature is replete with relatively small scale studies investigating various theories of reading. This research is often exploratory rather than confirmatory in nature. To avoid such limitations, samples from a large data base were used to examine causal models based on the Goodman theory of reading and the concepts of process and product comprehension. Two separate causal models were created using the following variables: graphic similarity, sound similarity, acceptability with prior text, acceptability with following text, acceptability or correction, the retelling score for the text read, the Comprehensive Tests of Basic Skills Vocabulary and Comprehension scores, and the Degrees of Reading Power (DRP) scores. The sample for one model consisted of 448 Grade Two to Grade Five students enrolled in a Chapter I program in the southwestern United States. The sample for the second model consisted of only the Grade Four and Grade Five students from the larger sample since DRP scores were not available for other students. In the hypothesized models graphic and sound similarity, and acceptability with prior and following were posited to load on a latent factor representing the unitary dimension of reading which in turn was posited to be causally related to process and product variables. Process variables included the acceptable or corrected score (RMI comprehending score) and the DRP score. Product variables included the CTBS scores and the retelling score. Product variables were posited to be dependent upon process variables. Analysis was conducted using the LISREL program. For both models causal pathways were dropped between process and product comprehension variables but were retained between the latent variables of reading and process and product comprehension. In addition, the DRP score loaded on product comprehension more than on process comprehension while retelling loaded more on process comprehension than product comprehension. Variables relating to the Goodman theory appeared to be more interrelated than those external to the theory. Implications for the uses of causal modeling and the constructs of process and product comprehension are discussed.

Organic polymers S2218600, S2429901 and S2219200 (referred to as Polymer 1, Polymer 2 and Polymer 3, respectively) of varying toxic potential, designed for use in cosmetic aerosols, were used as model substances to predict inflammatory potential. In vivo inflammogenic potential was evaluated by assessment of inflammatory cell profile (alveolar macrophage (AM), polymorphonuclear neutrophil (PMN)) of broncho-alveolar lavage fluid (BAL) 24hrs after a single instillation of either 0.5 mg or 2 mg polymer in Sprague Dawley rats. Pro-inflammatory Minusil particles and non-inflammatory titanium dioxide (TiO2) particles were used as controls. For comparison, cultured rat NR8383 AM-like cells, human THP-1 monocyte cells or human monocyte derived macrophages were treated with polymer for 24 h and supernatants analysed for indicators of cytotoxicity and inflammatory mediator release. In addition, after 6 h treatment, gene changes in the rat lung tissue and also in the rat NR8383 alveolar macrophage cell line were assessed using microarray to analyse the entire rat genome. The in vivo studies showed that Polymer 1, Polymer 3 and Minusil caused significant PMN influx into BAL. Polymer 3 and Minusil caused a significant increase in AM number in BAL. Polymer 2 and TiO2 had no effect on BAL cell profile. BAL tumour necrosis factor-α (TNFα) and macrophage inflammatory protein-2 (MIP-2) levels were significantly increased following instillation of Polymer 3 and Minusil. Thus the polymers and particles were ranked for potential to cause pulmonary inflammation: Polymer 3 > Minusil > Polymer 1 > Polymer 2 > TiO2. In vitro studies using cultured rat NR8383 AM-like cells showed that the polymers and particles could be ranked similarly for cytotoxic potential and their ability to stimulate the release of both TNFα and MIP-2. Cultured human monocyte derived macrophages detected the pro-inflammatory abilities of Polymer 3, as measured by cytotoxic potential and ability to stimulate TNFα, interleukin-8 (IL-8) and macrophage inflammatory protein-1α (MIP-1α), however, did not detect the pro-inflammatory abilities of Polymer 1. Cultured human THP-1 cells predicted the pro-inflammatory effects of Polymer 3 in rat lungs using the cytotoxicity assay and by changes in IL-1β, MIP-1α and IL-10 levels. The human THP-1 cell line did not predict the pro-inflammatory effects of Polymer 1 that were observed the rat lungs. Electron spin resonance (ESR) detected free radicals produced by the pro-inflammatory polymers and particles which had the ability to break bonds in super-coiled DNA and deplete intracellular glutathione (GSH). Microarray analysis of the canonical pathways activated by the pro-inflammatory polymers, Polymer 1 and Polymer 3, showed that 3 similar pathways were significantly activated in the instilled rats and the rat NR8383 AM-like cells following treatment. ‘Xenobiotic metabolism’, ‘IL-10 signalling’ and ‘leukocyte extravasation signalling’ pathways were significantly changed by the pro-inflammatory polymers. Use of these cell model alternatives in an industrial setting will refine and reduce in vivo testing and as these models are further developed and used alongside future new alternatives they will provide a substantial contribution towards the replacement of animal testing.

A new Maximum Likelihood Criterion (MLE) suitable for data which are recorded at unequal time intervals and contain auto-correlated errors is developed. Validation of the new MLE criterion has been carried out both on a simple two - parameter reservoir model using synthetical data and on a more complicated hillslope model using real data from the Pukeiti Catchment in New Zealand. Comparison between the new MLE criterion and the Simple Least Squares (SLS) criterion reveals the superiority of the former over the latter. Comparison made between the new MLE and the MLE for auto-correlated case proposed by Sorooshian in 1978 has shown that both criteria would yield results with no practical difference if equal time interval data were used. However, the new MLE can work on variable time interval data which provide more information than equal time interval data, and therefore produces better visual results in hydrologic simulations.

published_or_final_version / Civil and Structural Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Mathematics / Master / Master of Philosophy

published_or_final_version / Civil Engineering / Master / Master of Philosophy

published_or_final_version / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy