This document proposes a study designed to investigate the association between executive function abilities and social anxiety in a group of adolescent survivors of Acute Lymphocytic Leukemia (ALL) who were treated with chemotherapy for central nervous system prophylaxis. The proposed study is also designed to evaluate a possible interaction effect between executive function abilities and social skills in their impact on social anxiety in this population. The report provides detailed background information describing ALL and available treatments for the disease. It also reviews the literature on both acute and late effects of chemotherapy, with particular attention placed on understanding both neurocognitive and psychosocial effects in the context of adolescent development. The proposed project involves collecting parent and teacher reports to measure the constructs of Executive Function and Social Skills. Parent measures may be completed in English or Spanish. Self-reports of Social Anxiety symptoms in the adolescent survivor sample will also be collected. Simultaneous regression analyses will be used to analyze the influence of executive function abilities on social anxiety. Sequential multiple regression analyses will then be conducted to check for differences in the magnitude of the relationship between executive function abilities and social anxiety with varying levels of social skills. Significant results would inform the development of targeted interventions. For example, if it is determined that executive function abilities are indeed associated with social anxiety symptoms, existing programs focused on neurocognitive remediation could begin to monitor participants for anxiety and provide preventative therapeutic intervention. Additionally, if social skills is confirmed as a moderator, evidence-based interventions targeting the development of social skills in the survivor population would be warranted as well. / text

The objective of this thesis is to experimentally investigate the performance of steam gasification of chars of pure coal (lignite, sub-bituminous), pure biomass (radiata pine, eucalyptus nitens) and their blends. The influences of gasification temperature, types of coal and biomass, coal-biomass blending ratio, alkali and alkaline earth metal (AAEM) in lignite, on specific gasification characteristics (producer gas composition and yield, char reactivity) were studied. In addition, synergistic effects in co-gasification of coal-biomass blend char were also investigated. This project is in accordance with objectives of the BISGAS Consortium. In this study, experiments were performed in a bench-scale gasifier at gasification temperatures of 850°C, 900°C and 950°C, respectively. Two types of coals (lignite and sub-bituminous) and two kinds of biomass (radiata pine and eucalyptus nitens) from New Zealand were selected as sample fuels. From these raw materials, the chars with coal-to-biomass blending ratios of 0:100 (pure coal), 20:80, 50:50, 80:20 and 100:0 (pure biomass), which were derived through the devolatilization at temperature of 900°C for 7 minutes, were gasified with steam as gasification agent. During the gasification tests, the producer gas composition and gas production were continuously analysed using a Micro gas chromatograph. When the gas production was undetectable, the gasification process was assumed to be completed and the gasification time was recorded. The gasification producer gas consisted of three main gas components: hydrogen (H2), carbon monoxide (CO) and carbon dioxide (CO2). The results from gasification of chars of individual solid fuels (coal or biomass) confirmed that biomass char gasification was faster than coal char gasification. The influences of gasification temperatures were shown as: when gasification temperature increased, the H2 yield increased in coal char gasification but decreased in biomass char gasification. In the meantime, CO yields increased while CO2 yields decreased in both coal char and biomass char gasification. In addition, the char reactivity of all the pure fuel samples increased with elevated gasification temperatures. The results from co-gasification of coal-biomass blend char exhibited that the syngas production rate, which is defined as the total gas production divided by the gasification completion time, was enhanced by an increase in gasification temperatures as well as an increase in the biomass proportion in the blend. The AAEM species played a significant catalytic role in both gasification of pure coal chars and co-gasification of coal-biomass blend chars. The presence of AAEM increased the producer gas yield and enhanced the char reactivity. The positive synergistic effects of the coal-biomass blending char on syngas production rate only existed in the co-gasification of lignite-eucalyptus nitens blend chars. The other blend chars showed either insignificant synergistic effects or negative effects on the syngas production rate.

Macroalgal blooms are increasing world-wide and have negative effects on benthic invertebrates and sediments. These include loss of species diversity and development of hostile sediment environments. This thesis considers ecological effects of Ulva lactuca L., and its mechanical removal on benthic invertebrates and sediments in Avon-Heathcote Estuary, New Zealand. Benthic communities comprised 34 species from 12 groups recorded from seven sites during seasonal general surveys. Dominant groups at each site were Gastropoda and Bivalvia. The most abundant species were Austrovenus stutchburyi, Micrelenchus tenebrosus and Amphibola crenata. Community composition varied significantly between sites, and there were significant site-specific differences in abundances of most species between winter and summer. U. lactuca had the greatest seasonal variation. Several species correlated with U. lactuca biomass, and the strength of correlation for different species varied between sites. There were seasonal changes in sediment physico-chemical variables between sites with greatest change in the silt/clay fraction. The sediment variables silt/clay fraction, dissolved oxygen and temperature correlated with seasonal changes of patterns in benthic community assemblages. A similar study was carried out by Bressington in 2003. In both studies, Bivalvia and Gastropoda were the most abundant groups, with Gastropoda having a higher, and Bivalvia a lower, proportion in the present study compared with 2003. Summer communities were significantly different between the two studies. Compared with 2003 there were higher percentages of sediment pore water and volatile solids present in 2005. Experimental removal of U. lactuca was conducted by mechanical broom at two sites: an open, exposed central sand flat, and McCormacks Bay, a shallow, sheltered mud flat. Removing U. lactuca had several immediate effects. These included a significant decrease in abundance of mobile epifauna (Micrelenchus tenebrosus and Zeacumantus subcarinatus) and an increase in abundance of infauna, including Arthritica bifurca and Austrovenus stutchburyi. There was no effect of U. lactuca removal on Austrovenus stutchburyi condition and 46 days following removal, invertebrate abundances approached pre-removal levels at each site. U. lactuca removal also caused short-term increases in dissolved oxygen and temperature of pore water. The greatest visual impact of removing U. lactuca was to sediments in McCormacks Bay from trampling. It was concluded that the variables having the greatest effect on seasonal species distribution and abundance at each site were temperature and sediment grain size. Differences between the present study and the study in 2003 were due to differences in sampling procedure mainly due to the two different quadrat sizes. Greater accuracy in representing long-term changes in ecosystems would be achieved by using standard sampling protocols. Removal of U. lactuca by mechanical broom was effective and had low impact on benthic invertebrates and physico-chemical variables, but it should be used only in sandy habitats because of severe disturbance to soft-sediment environments. Options for management and control of U. lactuca in Avon-Heathcote Estuary are discussed.

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Fundamental investigations have been carried out on an Inductively Coupled Plasma (ICP) operated at 148 MHz, a frequency which is nearly three times higher than any previously reported for analytical ICPs used in spectrochemical analysis. High frequency operation is expected to provide easier sample introduction into the discharge, with a consequence of less energetic conditions in the central channel. Several plasma diagnostic techniques were employed in order to determine the conditions experienced by the analyte species in this source for spectrochemical analysis. Three different torch systems were investigated at 148 MHz and compared to the "standard" 27 MHz configuration. The highest excitation temperatures and electron densities were obtained in the 27 MHz configuration, and the lowest values in the largest torch at 148 MHz. Intermediate values were obtained in the intermediate-size torches at 148 MHz. These observations correlate reasonably well with the ratio of the plasma radius to the skin depth (r/s). The skin depth defines the region in which the majority of the electrical energy is deposited into the discharge, and is smaller at 148 MHz than at 27 MHz. The measurement of electron densities also allows the estimation of how closely a particular discharge approaches Local Thermal Equilibrium (LTE). As may be expected, LTE is most closely approached in the 27 MHz arrangement. The less energetic conditions characterized by lower temperatures and electron densities result in less intense analyte emission from the high frequency ICPs. Signal-to-Background ratios and detection limits reflect this trend, but the linearity of the calibration curves and freedom from vaporization interferences are not degraded. Finally, the introduction of organic solvents is much easier, and better detection limits in an organic matrix are obtained at 148 MHz. These investigations have shown the utility of classifying the effects of changing torch sizes and operating frequencies by means of the r/s ratio. This provides the analyst with a means of selecting the general range of conditions to be employed in a particular analysis.

The reactive nitric oxide species (RNOS) nitroxyl (HNO) has exhibited both beneficial and deleterious biological effects. In particular, HNO autoxidation can lead to harmful modifications of biomolecules, yet the products of HNO/O₂ remain undetermined. A conceivable product is peroxynitrous acid (ONOOH), however a comparison of the chemistry of HNO/O₂ to synthetic peroxynitrite (ONOO⁻) determined that these RNOS have distinct reactive profiles. This study compares the reactivity of HNO and NO⁻ in the presence of O₂ to synthetic ONOO⁻ and the autoxidation of HNO at high pH (NO⁻/O₂) in an effort to shed light on the products of HNO autoxidation. All species exhibited the capacity for two-electron oxidation, but differences between ONOO⁻ and NO⁻/O₂ and HNO/O₂ were observed in terms of one-electron oxidation, hydroxylation, nitration and buffer effects. NO⁻/O₂ exhibited a reactive profile similar to ONOO⁻, suggesting that protonation of ONOO⁻leads to a unique species from the autoxidation of HNO.