UQ Theses (RHD) - Official collection - UQ eSpace

An investigation into the genetics and physiology of sugar accumulation in sweet sorghum as a potential model for sugarcane.

Ritter, Kimberley Belle — 2008-11-21T00:00:00Z

Obtaining higher sugar yield is a major focus of sugarcane variety improvement programs, however the complex genome of sugarcane has hindered research and development of the crop. Sorghum and sugarcane are both members of the Andropogoneae tribe and comparative mapping has revealed a high level of synteny among the two closely related species. Sorghum is a diploid species with a small genome unlike sugarcane which has one of the most complex genomes of any organism. Particular varieties of sorghum, known as sweet sorghums or sorgos, accumulate high levels of sugar in stalk juice near the time of maturity, as does sugarcane. Based on this relationship between sorghum and sugarcane, this study aimed to investigate sweet sorghum as a genetic and physiological model for sugar accumulation in sugarcane. An F6 recombinant inbred line (RIL) segregating population with 184 progeny lines was developed from a cross between R9188, a dwarf conversion of the sweet sorghum line Rio, and R403463-2-1, a Queensland Department of Primary Industries and Fisheries (QDPIF) elite grain sorghum R-line. The population was evaluated in two field trials for 16 agronomic traits and eight sugar-related traits. A genetic linkage map of R9188 x R403463-2-1 was constructed integrating 225 polymorphic bands produced by 38 AFLP primer pairs, 37 Xtxp SSR and six sugarcane SSR markers. The constructed map had 16 linkage groups (LG), of which 10 could be assigned a chromosome on the basis of shared markers between this map and previously published maps of sorghum and sugarcane, and spanned a total length of 2012.9 cM (including unknown LG). Eleven traits were analysed for QTL identification; seven sugar-related traits (sucrose content, glucose content, fructose content, sugar content, sucrose yield, sucrose to sugar ratio and Brix) and four agronomic traits (height, DTF, total dry matter and grain yield). Fifty-five marker were associated with the 11 traits from the two field trials, of which 15 were identified in both trials which is not unexpected considering the high heritability of the traits in the field trials. QTL generally colocated to five major locations. QTL from R9188 were found for sucrose content, sugar content and sugar yield on chromosomes SBI-01, SBI-05 and LG-U6. R9188 also contributed QTL for Brix on SBI-05 and LG-U6, and sugar content on SBI-03. QTL from R403463-2-1 were found for sucrose content and sucrose yield on SBI-10, and glucose content on SBI-07. QTL for height, days to flowering and total dry matter, were located on SBI-01 from R403463-2-1, and on LG-U6 from R9188. QTL for grain yield from both R403463-2-1 and R9188 were found on SBI-03. Three of the sorghum chromosomes (SBI-01, SBI-03 and SBI-05) that contained QTL for sugar-related traits, also contained sugarcane SSRs that mapped in sugarcane to three homology groups (2, 3 and 4) with strong QTL for sugar-related traits suggesting that similar loci for sugar-related traits are being detected between sweet sorghum and sugarcane. Field and glasshouse trials were conducted to investigate the accumulation of sugars spatially within the stem and developmentally at anthesis and post-black layer in sweet sorghums. A stem sugar profile in sweet sorghums had not previously been created at post-black layer and it was found that in the glasshouse trial, the sucrose increased toward the base of the stem, in the same manner of accumulation seen in sugarcane. Like sugarcane, the sucrose in the sweet sorghums accounted for 90% of the soluble solids (sucrose to total ratio) at the end of the crop cycle. A comparison of profiles was also conducted between a sweet and grain sorghum, fertile sorghum and their sterile counterpart, sweet sorghum and the dwarf conversion, and high Brix and low Brix progeny of the R9188 x R403463-2-1 population. At post-black layer, the sweet sorghum had higher sucrose than the grain sorghum, and higher sugars were found in the sterile versions compared to the fertile versions. Sugar accumulation had not been previously investigated in dwarf converted sweet sorghums; R9188, the dwarf version of Rio, was significantly lower in whole-plant sucrose at post-black layer, but no difference was noted in individual stem sections. No clear distinction could be made between the high Brix lines and the low Brix lines, sampled at post-black layer, for sugar-related traits at a whole-plant or stem section level. The genetic relationship of sweet and grain sorghums, within S. bicolor ssp. bicolor, was investigated for the first time. Ninety-five genotypes, including 31 sweet sorghums and 64 grain sorghums, representing all five races within the subspecies bicolor, were screened with 277 polymorphic AFLP markers. The sweet sorghum lines were largely distinguished from the others, particularly by a group of markers located on SBI-08 and SBI-10, and although the clusters obtained did not group clearly on the basis of racial classification; the sweet sorghum lines often clustered with grain sorghums of similar racial origin thus suggesting that the high stem sugar in sweet sorghums occurred independently or was independently selected in several different genetic backgrounds within S. bicolor ssp. bicolor. In this study, great steps have been made in determining the use of sweet sorghum as a genetic and physiological model for sugar accumulation in sugarcane. From a genetic perspective, similar loci for sugar-related traits were detected between sweet sorghum and sugarcane, thus indicating that sweet sorghum is likely to be a good genetic model for sugar accumulation in sugarcane. In sweet sorghum, the markers associated with the sugar-related traits will be a valuable resource for future markerassisted selection for these traits in a sweet sorghum breeding program. However, the diversity study suggested that the high stem sugar in sweet sorghum occurred independently or was independently selected in several different genetic backgrounds, which is in contrast to the possible monophyletic origin of high stem sugar in sugarcane. From a physiological perspective, the sucrose levels increased toward the base of the stem in sweet sorghum and accounted for 90% of the soluble solids at the end of the crop cycle, in the same manner of accumulation seen in sugarcane, suggesting that sweet sorghum could be a physiological model for sugarcane. Thus, sweet sorghum could be used as both a genetic and physiological model for sugarcane.

An investigation into the potential of mesenchymal stromal cells to attenuate graft-versus-host disease

Melinda Elise Christensen — 2010-06-02T00:00:00Z

Survival of patients with poor prognosis or relapsed haematopoietic malignancies can be markedly improved by allogeneic haematopoietic stem cell transplantation (HSCT). HSCT reconstitutes the immune and haematopoietic systems after myeloablative conditioning and inhibits the recurrence of the malignancy by a graft-versus-leukaemia (GVL) response mediated by donor T cells. However, significant post-transplant complications such as graft-versus-host disease (GVHD) continue to plague the event-free survival of this curative procedure. GVHD is facilitated by donor T cells that recognise histocompatibility antigens on host antigen presenting cells (APC), such as dendritic cells (DC). Current treatment options for GVHD are focused on these T cells. However, these treatments result in an increased incidence of infection, graft rejection and relapse. A novel means of immunosuppression in GVHD is the use of multi-potent, mesenchymal stromal cells (MSC). MSC are non-immunogenic cells that actively suppress T cell function in vitro, and can resolve steroid-refractory GVHD in the clinic. Despite their use in the clinic, there is a paucity of pre-clinical data. Our aim was to investigate the in vivo efficacy of MSC to control GVHD while maintaining the beneficial GVL effect, and to begin to understand the mechanism by which MSC exert their immunosuppressive effects. We isolated and characterised MSC from murine bone/bone marrow and demonstrated that they suppressed T cell proliferation in vitro, even at low ratios of 1 MSC per 100 T cells. This was true of both donor-derived MSC, and MSC derived from unrelated donors (third party). Importantly, we observed that MSC significantly reduced T cell production of the pro-inflammatory cytokines TNFα and IFNγ in culture supernatants and that IFNγ plays a key role in the ability of MSC to suppress T cell proliferation. In vivo, we examined the effects of donor-derived MSC on GVHD severity and onset in two myeloablative murine models of HSCT. A major histocompatibility complex (MHC)-mismatched donor-recipient pair combination was used as a proof–of-principle model [UBI-GFP/BL6 (H-2b)àBALB/c (H-2d)], and an MHC-matched, minor histocompatibility antigen (miHA) mismatched donor-recipient pair combination was used to mimic MHC-matched sibling transplantation [UBI-GFP/BL6 (H-2b)àBALB.B (H-2b)]. We examined a number of variables related to MSC infusion including timing, dose and route of injection. We found that early post transplant infusion of MSC by the intraperitoneal injection was most effective at delaying death from GVHD, compared to pre-transplant infusion or intravenous injection. Furthermore, we found that the dose of MSC was critical, as infusion of too few MSC was ineffective and infusion of too many MSC exacerbated the development of GVHD. Taken together, these results suggest that timing, dose and route of injection are all important factors to be considered to ensure successful therapeutic outcome. To investigate the in vivo mechanism of action, we conducted timed sacrifice experiments in the MHC-mismatched model to determine if MSC altered cytokine secretion and cellular effectors, such as DC, known to play a key role in GVHD. Despite the fact that MSC given post-HSCT enter an environment full of activated DC and IFNγ levels, by day 3 and 6 post infusion, these activated DC and IFNγ levels are decreased compared to controls or mice infused with MSC pre-transplant (p<0.05). This confirmed our in vitro data that IFNγ played an important role in MSC-mediated immunosuppression. In addition, when we removed a major source of IFNγ production in vivo by administering the T cell depleting antibody KT3 to mice with or without MSC, we found that although T cell depletion prolonged survival, MSC were unable to further enhance this effect. This was also true when MSC were used in combination with the conventional immunosuppressant cyclosporine. Finally, we examined whether the infusion of MSC would compromise the GVL effect. We found that whilst MSC could delay the onset of GVHD, in our model they did not alter the anti-tumour effects of the donor T cells. Overall, we have shown that MSC can delay but not prevent death from GVHD when administered at an appropriate time and dose and that IFNγ is required for MSC-mediated immunosuppression in our model. These data suggest that patients undergoing HSCT should be monitored for IFNγ, and administered MSC when high levels are reached. Whilst MSC may be a promising therapy for patients with severe GVHD, we highlight that further investigation is warranted before MSC are accepted for widespread use in the clinic. The risks and benefits for transplant recipients should be carefully considered before utilising MSC to treat or prevent GVHD.

An Investigation of Beginning Teacher Self-Efficacy for the Arts in the Middle Years of Schooling (years 4-9)

Susanne Garvis — 2010-11-10T00:00:00Z

This study sought to investigate beginning teacher self-efficacy for the arts in the middle years of schooling (years four to nine). In Queensland, Australia, it is a curriculum requirement and expectation that generalist beginning teachers shall teach the arts (dance, drama, media, music and visual arts) as part of the compulsory curriculum. Generally it is assumed that beginning teachers acquire relevant arts knowledge and skills in pre-service teacher education. During pre-service teacher education, it is assumed that beginning teachers will develop positive teacher self-efficacy, leading to future teacher effectiveness in teaching arts education. Research suggests however, that many generalist teachers do not feel confident or capable in teaching the arts in their classrooms. This implies that beginning teachers do not have positive teacher self-efficacy beliefs. Few studies have investigated current levels of beginning teacher self-efficacy for arts education, how teacher self-efficacy beliefs are formed and what influences teacher self-efficacy beliefs in school contexts. Little is also known about developing and supporting positive teacher self-efficacy beliefs towards arts education in the middle years classroom (year four to nine). Through this investigation, I sought to address this void through identifying existing beginning teacher self-efficacy beliefs and the ways in which individual self-efficacy beliefs may be shaped through schools, community and policy initiatives. I sought to identify ways that beginning teacher self-efficacy beliefs for the arts could be supported and maintained within schools. Consequently, the importance of this study lies in its exploration of the ways that beginning teacher self-efficacy beliefs for arts education shape perceptions of teacher effectiveness in the classroom. Using a mixed method approach, the study was undertaken in two phases. In the first phase, 201 beginning teachers participated in a questionnaire that provided a snapshot of current teacher self-efficacy beliefs towards the arts across Queensland. Using an adapted teacher self-efficacy scale, I was able to measure teacher self-efficacy for each of the arts disciplines. I was also able to examine contributors from the school environment and policy agenda that influenced beginning teacher self-efficacy beliefs for the arts. In the second phase of the study, to add depth and understanding to individual beginning teacher experience in relation to findings from the questionnaire about teacher self-efficacy for the arts, I employed a narrative-informed case study approach. Four different school contexts were chosen across Queensland, and interviews were conducted with beginning teachers and principals. Field notes and observations were also collected. Using a narrative approach, data were analysed and presented as four story constellations. Each constellation revealed the beginning teacher’s self-efficacy for the arts, and the ways in which these were shaped by collective school efficacy. The influence of community, curriculum reform and policy reform also became known, directly and indirectly influencing beginning teacher self-efficacy with the arts. The findings trouble some of the taken for granted assumptions about teaching arts education in generalist middle years classrooms. Beginning teachers revealed a diverse range of beliefs towards the arts. Questionnaire data established that beginning teacher self-efficacy for each of the arts disciplines was significantly lower compared to the teaching of Maths and English. Beginning generalist teachers suggested they do not have adequate content knowledge and skills, received limited support and had few opportunities for professional development. The story constellations revealed the influence of school beliefs, community beliefs and policy beliefs on beginning teacher self-efficacy for the arts. When the story constellations were placed side by side, they brought to the surface critical points for discussion and analysis about collective efficacy, subject valuing, supportive networks available and training of generalist teachers. Findings provide key messages for schools, teacher educators, administrators, policy makers, the community and the arts industry about supporting beginning teacher self-efficacy for the arts. Findings also reinforce areas of need and development for future policy initiatives that encourage and support teacher self-efficacy for the arts in the middle years of schooling (years four to nine). Since the arts are considered an integral part of the curriculum for students in Queensland, a shared responsibility for the delivery of quality arts programs is needed with a democratic approach to planning, policy and implementation.

An investigation of high-volume fly ash concrete for pavements

Lu, Yuan — 2008-11-21T00:00:00Z

An investigation of strategies to teach word processing skills to young adults with intellectual disabilities

Lloyd, Janette Mary — 2008-11-21T00:00:00Z

This research project had two aims. The first aim was to develop guidelines to assist in the selection and evaluation of computer software packages for use in a literacy program for young adults with intellectual disabilities. The second aim was to develop, implement, and evaluate strategies to enable learners with intellectual disabilities to work independently with a word processing program. Three studies were undertaken to achieve these aims. The first was the preliminary study, the second was the main study, and the third study was an extension of the main study to a larger classroom context. The preliminary study was conducted to develop guidelines that could be used to gather information about three commercial educational software programs that were available at the time and were being promoted as effective tools in the teaching of literacy. A range of characteristics and qualities of effective programs was identified from a review of the literature and these findings were used to develop checklists to assess available software. Findings from the preliminary study revealed a need to further explore the learners needs and skills when using software packages such as Microsoft Word 98 in classroom settings. These findings formed the basis for the main study. The aim of the main study was to develop, implement, and evaluate teaching strategies to enable students with intellectual disabilities to work independently with word processing using Microsoft Word 98. Action research was adopted as the research design for the main study. The participants in the main study were 11 young adults with intellectual disabilities ranging in age from 18 to 25 years. In the Initial Reconnaissance Phase, a combination of formal standardised assessments, informal researcher developed instruments, and informal assessments were used to collect data about the participants computer skills, comprehension skills, vocabulary, interests, attitudes and behaviours. Using the findings from these assessments, a General Plan was developed to teach a specific computer skill - saving and retrieving documents from a specific folder. A pre-test was administered prior to the commencement of the teaching sessions and then readministered as a post-test at the conclusion of the sessions. The participants were then observed in their regular classroom to determine if the skill had been retained after a 10-week period. The findings from the post assessments showed positive results for all participants in the study. The study was then extended to a larger group of learners in a classroom setting. The classroom study included all learners in the group (n=10). The General Plan was revised but as it proved to be successful in its original format, few changes were made. In the classroom study, the post-tests revealed that seven participants were able to save and retrieve documents independently from a specific folder, and three participants were not able to save independently. The study indicated a range of strategies that could be used to help the remainder of the learners build towards gaining the targeted computer skills. The results from this investigation add to the current body of knowledge about software evaluation and teaching strategies that can be used to enhance the computer skills of young adults with intellectual disabilities. These findings have important implications for the design of literacy programs and how technology can be used as a teaching tool to create a richer teaching environment.

An investigation of the genetic components controlling reproduction, germline development and sex in Marsupenaeus japonicus (Bate).

Tamera Callaghan — 2011-09-20T00:00:00Z

Significant advances in the domestication and genetic improvement of cultured penaeid shrimp species have been achieved globally. The domestication of species, including Litopenaeus vannamei, Penaeus monodon and Marsupenaeus japonicus, has enabled the production of stocks selectively bred for fast growth, disease resistance, improved survival and improved feed conversion efficiency (Argue et al., 2002; Preston et al., 2004; Preston et al., 2010; Glencross et al., 2010). As progress is made in selective breeding, the production of reproductively sterile stocks that are protected from unwanted or unlicensed breeding has become a research priority. Furthermore, penaeids are sexually dimorphic with females growing significantly larger than males. This is commercially important as the production of all-female populations would increase pond yields. Currently, a limited knowledge of the genetic basis of reproduction, germline development, and sex determination and differentiation restricts further progress in this research area. Several methods have been investigated to produce reproductively sterile and/or all-female populations of shrimp, including irradiation, polyploidy and hybridization (Sellars et al., 2006, 2007; Benzie et al., 2001). Although these methods have had varying degrees of success, a method that confers 100% sterility or all-female populations is yet to be achieved. This study aims to increase our understanding of the genetic basis of reproduction, sex and germline development in M. japonicus in an effort to produce reproductively sterile, all-female stocks for commercial production. The three principal components of this study are; (1) the identification of genes involved with gonad development and sexual differentiation; (2) the identification and characterization of an evolutionarily conserved germline specific gene; and (3) the assessment of RNAi as a technique to produce loss-of-function phenotypes for a germline gene. To identify genes involved with gonad development and sexual differentiation, expressed sequence tags (ESTs) were identified from reciprocal suppression subtractive hybridization (SSH) cDNA libraries from M. japonicus female and male gonads. Random sequencing of 576 clones from the two libraries revealed 296 unique ESTs. The expression profiles of 24 of these ESTs were determined in female and male gonads and developing post-larvae by qPCR. When expression was determined in gonads, six of the ESTs were expressed in ovaries only and five of the ESTs were expressed in testes only. When expression was determined in whole individuals during post-larval development, expression of the ESTs was low and inconsistent until stage PL110 (110 days since metamorphosis from mysis stage to the first post-larval stage). At PL110, seven of the ESTs were detected in females only and seven ESTs were detected in males only. Sex-specific expression at this developmental stage indicates that these ESTs act as important gonadal development markers and may have a role in gametogenesis. To further understand the genes involved with germline development and reproduction, a comparative approach was used to identify vasa, an evolutionarily conserved gene involved with germline specification. Vasa is a DEAD-box ATP-dependent RNA helicase that has a key role in germline development in many animals. Vasa orthologues were isolated from M. japonicus and P. monodon, and were named Mj-vasa and Pm-vasa respectively. The deduced amino acid sequences from Mj-vasa and Pm-vasa contained all of the conserved DEAD-box family motifs and three CCHC zinc finger repeats in their N-termini. Mj-vasa expression was examined in female and male broodstock tissues, as well as during ovarian, embryonic and larval development. Using qPCR and in situ hybridization, Mj-vasa transcripts were detected in the female and male gonads, and were localized to the cytoplasm of oocytes in female broodstock. Mj-vasa transcript abundance decreased during ovarian development. During embryogenesis and larval development, Mj-vasa transcripts were most abundant in zygotes, indicating that it is maternally expressed. Mj-vasa mRNA levels decreased between 2 hours (h) and 4 h post-spawning, and remained at low levels throughout embryogenesis and larval development. These results suggest the Mj-vasa may have a role in germ cell development and may be able to be used as a germline marker in M. japonicus. To assess whether germline and gonad genes can be knocked down to result in loss-of-function phenotypes, Mj-vasa-dsRNA was administered to female M. japonicus broodstock. The expression of Mj-vasa, six ESTs that were expressed in the ovary only and an EST that is expressed similarly in ovaries and testes were examined in control and dsRNA injected animals using qPCR. In the control animals, the expression of Mj-vasa and the six ovary specific ESTs decreased during ovarian development. In the Mj-vasa-dsRNA-injected animals, two individuals had a lower level of Mj-vasa expression than control animals with similar GSIs. This decreased level of Mj-vasa expression may have been the result of knockdown by the Mj-vasa-dsRNA injection. However, inhibition of gonad development was not observed in these individuals. Variation in gene expression and natural variation in ovarian development during a moult cycle made it difficult to assess the effect of dsRNA injection on Mj-vasa transcript abundance and ovarian development. These factors demonstrate the importance of determining the natural baseline expression level of target genes and the need to account for biological variation amongst individuals when performing gene regulation experiments. In this project a range of molecular tools were applied to identify genes involved with reproduction, sex and germline development in M. japonicus. A number of candidate genes were identified for future gene regulation studies which aim to produce reproductively sterile and/or all-female shrimp populations.

An Investigation of the Impact of Note Taking on the Quality of Mock Jurors’ Decisions

Tanya Strub — 2010-04-05T00:00:00Z

Abstract This research investigated the extent to which taking notes influenced the quality of mock jurors’ decisions. High quality decisions were defined in this research as those which did not reflect the influence of the offender stereotype. The impact of note taking on the quality of jurors’ decisions is central to the judicial community’s concerns about note taking as a jury aid and their willingness to offer it in trial contexts. Previous research has argued that note takers make better quality decisions than non-note takers because note takers recall more trial content and make judgements that better reflect the evidence presented. However, according to dual process models of persuasion, high quality decisions should show evidence of both effortful processing of information and no influence of peripheral cues, such as stereotypes. To date, the existing literature has neglected to consider the extent to which note takers, as compared to non-note takers, are influenced by peripheral cues. The current research sought to address this by investigating the extent to which note taking and non-note taking mock jurors were influenced by stereotypes when making decisions in a mock criminal trial. In particular, note taking and non-note taking mock jurors were presented with a criminal trial in which either a male or female defendant had been charged with a stereotypically masculine crime (e.g., aggravated robbery or murder). The extent to which mock jurors were more likely to convict the male defendant and acquit the female defendant was used as a marker of the extent that stereotypes about offenders influenced participants in these studies. Across studies, note takers’ perceptions of guilt, evaluation of the defendant, and, in some instances, recall of trial content, reflected stereotype-based processing while the corresponding measures for non-note takers did not. This research then went on to investigate why note takers were more vulnerable to the influence of stereotypes than non-note takers. It was proposed that one reason might be the requirement that note takers simultaneously record and evaluate trial content. Previous research has shown that persons engaged in dual tasks rely on stereotypes to increase information processing efficiency and are therefore able to re-direct cognitive resources to the additional task. Consistent with previous studies, the current research found that both note takers and mock jurors engaged in an additional task during the trial were more vulnerable to the influence of stereotypes than non-note takers. Furthermore, whilst investigating interventions designed to reduce the influence of stereotypes on note takers’ decisions, results revealed that such interventions were less successful in improving decision quality than interventions that removed the requirement to engage in dual tasks. In particular, the influence of stereotypes was reduced when note takers were encouraged to elaborate on the content of their notes during designated review periods. Whilst methodological features of this research program--namely a reliance on student samples and the relative brevity of mock trials used--may have led to an underestimation of the reliance on stereotypes for note takers, the research has implications for the instructions given to jurors about note taking in judicial contexts. Specifically, the central conclusion of the thesis is that it would seem prudent to amend instructions to direct note takers to engage in the effortful review of their notes prior to coming together to reach a verdict.

An Investigation of the Impact of Physical Education on the Attitudes and Exercise Behaviour of Lower Secondary School Students in Chiang Rai, Thailand

Lekkla, Phitak — 2008-11-21T00:00:00Z

The purpose of this study was to investigate the impact of physical education on the attitudes and exercise behaviour of lower secondary students in Chiang Rai province, Thailand. This study was designed in two phases of investigation. First, a quantitative study was undertaken using a questionnaire given to 500 students designed by the researcher that aimed to ascertain the attitudes toward exercise, exercise behaviours and problems in doing exercise. The aim of the study was to provide preliminary data on the likely aspects of the impact of physical education curriculum on the students lives. The second phase of the investigation was a qualitative study using an in depth semi-structured interview of 30 active and 30 inactive students selected on the basis of their responses in the first phase. Ten physical education teachers and five school administrators across the range of schools in the investigation were also interviewed. This phase aimed to examine the effectiveness of physical education teaching and learning especially with the implementation of the new PE curriculum. Data from Phase 1 were analysed using a Statistical Packages for Social Sciences for Windows (SPSS for Windows). The second phase was analyzed descriptively from transcriptions of the audio-tapes of the interviews and from these themes and category responses were developed. Inter-rater reliability was obtained. The findings from Phase 1 showed that students thought that PE provided in school was worthwhile for their life. Most students reported that they have positive attitude towards exercise and believed that exercise had health benefits. Also, in Phase 2 most students both active and inactive agreed that PE activities learnt from classes could help them to have knowledge and skills for a healthy lifestyle after they finish school. However, the most salient finding concerned students knowledge about the basic principles of exercise such as warming up, cooling down, duration and frequency of exercise for health. It is necessary to provide these content on physical education curriculum to fill these gaps. Three major factors influenced students exercise behaviour. First, students interests and motivation to exercise. Most of them exercised to have fun, have friends and becauses it was good for their health. Second, the content of PE curriculum provided in PE classes influenced their exercise behaviour. The majority of active students reported that they preferred sport as the first priority. In contrast, inactive students preferred recreation but sports would be their last choice. The last factor was perceived barriers to exercise. Generally, students did not have many barriers to exercise. However, poor sports skills and having to help their parents to do household chores were the major barriers for some students especially for inactive students.

An investigation of the means of making eHealth more relevant to low socioeconomic communities

Dart, Jared Magnus — 2008-11-21T00:00:00Z

This thesis project investigated the means of making eHealth more relevant to low socioeconomic status (SES) communities. As with other information and communication technology (ICT) based initiatives, the uptake of eHealth is limited by access to technology. Online health information may be a means of providing increased access to health information. However, access to online health information and health information in general is disparate amongst sections of the populations. Middle and high SES communities, as well as the well-educated generally have high access to health information yet paradoxically they are less affected by modifiable/preventable diseases which can be influenced by effective health education. Therefore the challenge for health education and eHealth is how to reach those in low SES communities. This thesis employed three phases of research to answer this question. The first phase of the project investigated means of providing community based access to ICT in very low SES communities in India in order to provide data as to how such community based structures might deliver community oriented health information. The second phase investigated an online community portal to establish whether this would be a useful means of contextualising online health information and whether it could be the online counterpart to the community based ICT structures investigated in phase one. Phase three sought to determine what types of health information community members from various SES communities wanted and how their preferences as well as those of medical students might affect the design of a community eHealth approach. This thesis employed case study methodology to provide rich qualitative data in an area of research which is highly influenced by socioeconomic, socio-political and personal factors. The case studies which focused heavily on direct observation and key informant interviews as well as document analysis in turn informed the development of a series of community and medical student surveys which sought to provide a broader sample of opinions as well as quantitative data. The first phase investigated several community based ICT strategies a hub and spokes telecentre model, a similar but less tightly structured model which employed a community portal, and a mobile community access point - to determine how they might be utilised to facilitate eHealth uptake in low SES communities. These field studies, based in India, found that a hub and spokes model with peripheral field sites supported by a central knowledge hub would be a useful model to facilitate the delivery of appropriate health information. Information intermediaries at these peripheral sites could occupy a key role in delivering health information in an appropriate manner, as well as training individuals how to access appropriate health information independently. In addition, these studies identified a number of features necessary for a community based ICT access strategy employed for eHealth purposes. Making information relevant to the local context, as well as facilitating community access to health information, has been a challenge to the eHealth and wider health community. One means of achieving this employed by the UNITeS case study in phase one was an online community portal that delivers information relevant to a defined geographical area. The second phase of this project investigated the application of a non-health oriented community portal in a low SES community in South East Queensland, Australia, in order to determine how such a structure might be applied for eHealth purposes. This study demonstrated that there are significant problems associated with community members initiating and administering a community portal, especially regarding financial constraints and access to appropriate infrastructure. However, there are also a number of potential benefits of such a localising strategy being employed for eHealth. It is a useful means of contextualising information and providing access to practical information about local health resources; it may provide a recognisable contact point for health information seekers mediating their access to relevant and accurate online health information; and it provides greater proximity to community members and information seekers than a national health information portal. The third phase of research characterised the current health information environment in a low SES community and compared it to a mid-high socioeconomic SES community and to university students and staff. Through field work which included direct observation, key informant interviews, and surveys I explored the community demand for more health information, the current and preferred future use of health information sources, ascribed importance and trust of health information sources, the use of the local doctor as a source of health information, and the use of the internet for health information seeking. Results indicated a demand across all three communities for more health information, a remarkable concordance in the use of health information sources other than the internet, and that the local doctor is the most important and preferred source of health information. In addition, the research highlighted the importance of proxy health information seeking and the infrequent actual use of the doctor as a source of health information, despite community demand for more health information and stated preference for information from this source. The research also investigated the communitys requirements for a community eHealth strategy through key informant interviews in a low SES community, as well as through the survey research described above. Results revealed that community members requirements differed between the low and mid-high socioeconomic communities as well as from university students and staff. This was in part influenced by exposure to the internet as a source of health information, but also to the information needs of the various communities. This finding, not previously demonstrated in the eHealth literature, illustrates the need for a community specific approach. The survey results, thus, offer valuable guidance for the development of such an approach. Lastly, this project investigated the attitudes of medical students the doctors of the future to the current health education environment in which they are to practise, to the priority eHealth policies, and to potential components of a community oriented eHealth strategy. I found that most medical students believed that the current health system did not allow them to educate patients about their health issues, and that the principal constraint was inadequate time. Results indicated that the majority of students supported a patient information prescription system and community health portal to facilitate health information delivery, as well as delineating their attitudes to the various types of health information which should be provided by such a system. The final chapter presents a model for a community eHealth system which incorporates the findings of this research and addresses the needs identified through stakeholder consultation, as well as identifying areas for future research, including an action research project investigating a community oriented eHealth architecture. The model identified includes components for community based and hospital based delivery of health information; a means for keeping the clinician engaged with the health information process, fulfilling their role as coordinators of health care whilst allowing auxiliary health personnel to deliver basic health information; as well as an online means of coordinating the delivery of health information identified as important by community members. Specific, complex patient oriented health information should remain the domain of clinicians. This research has several limitations largely stemming from the fact that it is highly novel and covers a broad research area. As a result, a lot of the research is exploratory and raises many more questions than it answers. Nevertheless, it is a unique contribution to an internationally neglected area of research.

An investigation of the relationship between body composition, inflammatory adipokines and asthma in children: Asthma Fit Study

Arshi, Mandana — 2012-11-21T00:00:00Z

An Investigation of the Relationship between Posttraumatic Stress Disorder and Chronic Pain due to Whiplash Injury.

Rachael Dunne — 2011-02-03T00:00:00Z

Whiplash associated disorders (WAD) are a common and incur substantial personal and economic costs. This is a complex condition involves both physical and psychological impairments and research has shown that a persistent posttraumatic stress reaction is associated with poor functional recovery (Buitenhuis, de Jong, Jaspers, & Groothoff, 2006; Sterling, Kenardy, Jull, & Vicenzino, 2003). Many studies have demonstrated general support for the fact that Posttraumatic Stress Disorder (PTSD) influences the experience of pain; however, the specific mechanism through which this may operate has not yet been clearly established. One possible mechanism is an abnormal stress system function, involving psychophysiological reactivity and disturbances in the sympathetic nervous system; however empirical testing of this hypothesis is limited. Guided by theoretical models (Asmundson, Coons, Taylor, & Katz, 2002; Asmundson, Stein, & McCreary, 2002; Keane & Barlow, 2002; Liedl & Knaevelsrud, 2008; Sharp, 2001; Sharp & Harvey, 2001; Vlaeyen & Linton, 2000), the present research aimed to explore the nature of the relationship between PTSD and chronic pain due to whiplash injury through two empirical studies. The first study investigated the impact of comorbid PTSD on mental and physical health outcomes in seventy-two individuals with chronic WAD. Participants were classified into two groups, according to diagnosis of current injury-related PTSD based of the Structured Clinical Interview for DSM-IV (SCID) (PTSD: n = 33; No PTSD n = 39). The first part of the study utilised a cross sectional design to assess differences between individuals with and without PTSD on self-report measures. Results indicated that those with PTSD were more likely to report greater number of locations of pain (particularly back and shoulder pain), medication use (specifically analgesics and anti-depressants) and general disability (as measured by the SF-36). While there was a trend for individuals with PTSD to report more neck disability (as measured by the Neck Disability Index) this did not reach significance. Significant relationships were however found between neck disability levels and PTSD severity (particularly the avoidance and hyperarousal subscales). Significant relationships were also found between physical health (as measured by the SF-36) and PTSD severity (particularly the avoidance subscale). An additional aim of this first study was to examine the direct impact of activation of PTSD symptoms on affect, arousal and pain threshold measures. Utilising an experimental design, individuals with and without PTSD underwent a series of sensory pain threshold measures under standard conditions and again after exposure to an individually relevant trauma cue. As expected, under standard conditions individuals with PTSD reported more negative affect and pain and demonstrated greater physiological arousal and lower sensory pain thresholds than those without PTSD. Exposure to specific trauma cues resulted in significantly greater increases in physiological arousal and negative affect for those with PTSD compared to those without PTSD. Changes in sensory pain thresholds between and across the groups revealed mixed results. As predicted, individuals with PTSD demonstrated lower pain thresholds compared to those without PTSD across all sensory measures at baseline. For individuals with PTSD, exposure to the trauma cue resulted in further significant decreases in cold and pressure pain thresholds at the site of injury (i.e. a hyperalgesic effect) however, no significant changes in self-reported pain or heat and remote pressure pain thresholds were found. As expected, for individuals without PTSD the trauma cue had minimal impact on any sensory pain threshold measures. Building on the findings of study 1 and previous research reporting poorer WAD outcomes (Buitenhuis, et al., 2006; Sterling, et al., 2003) and responses to physical therapies for individuals with comorbid PTSD (Jull, Sterling, Kenardy, & Beller, 2007), study 2 aimed to assess treatment of PTSD within a chronic WAD sample. Trauma-focused Cognitive Behavioural Therapy (CBT) has shown moderate effectiveness in chronic pain samples however, there have been no clinical trials within WAD and thus Study 2 aimed to fill the gap in this research. The impact of the PTSD treatment on disability, physiological arousal and sensory pain thresholds was also investigated. Individuals with both chronic WAD and PTSD (taken from the PTSD group in study 1) were randomly allocated to either CBT (n = 13) or a waitlist control (n = 13). Treatment effects were evaluated at 10-12 weeks and 6-month follow-up, using a structured clinical interview for DSM-IV TR (SCID), self-report questionnaires and measures of physiological arousal and sensory pain thresholds. Results indicated clinically significant reductions in PTSD symptoms in the CBT group compared to the waitlist group at the post-assessment. Further gains in the PTSD group were also noted at the follow-up. The treatment of PTSD was also associated with improvements in self-reported disability (as measured by the NDI) and improved physical, emotional and social functioning and physiological reactivity to trauma cues, however minimal changes in sensory pain thresholds were observed between groups or over time. This study provides support for the effectiveness of trauma-focused CBT to target PTSD symptoms within chronic WAD. The finding that treatment of PTSD resulted in improvements in self-reported disability and quality of life with minimal changes in sensory pain thresholds highlights the complex and inter-relating mechanisms that underlie both WAD and PTSD. The theoretical and clinical implications of the results and the need for development and refinement of the understanding of these comorbid conditions through future research is discussed.

An investigation on rail squat prediction due to Rolling Contact Fatigue

Farjoo, Mohammadali — 2013-03-13T11:27:31Z

An Isotopic, Geochemical and Petrological Investigation of Organic Matter-rich Archaean Metasediments from the North Pilbara Terrane, Pilbara Craton, Western Australia: In Search of Early Life.

Lawrence Duck — 2009-11-17T00:00:00Z

Various organic compounds, including graphitic carbon, can be formed abiotically in hydrothermal systems, such that evidence for early life must necessarily combine geological, morphological and geochemical data to be compelling. Carbonaceous materials (CM) have been isolated from three rock packages of mid to early Archaean age from the Pilbara Craton of Western Australia. This CM has been subjected to a multidisciplinary approach utilising a variety of analytical and observational techniques, in an attempt to establish the occurrence, associations, mineral affinities, historical environments of growth, and the metamorphic/thermal history experienced by what may be some of the earliest, relatively pristine record of 3500 million year old life on this planet. CM isolated from drillcore obtained from the first of these localities, the 3.24 Ga Sulphur Springs volcanic hosted massive sulphide (VHMS) deposit, occurs as isotopically light (δ13C values of −34.0 ‰ to −26.8 δ13C) finely striated, lenticular to banded material emplaced parallel to original sedimentary bedding planes within the fine-grained silicified epiclastic hanging wall sediments. Petrological and transmission electron microscopy (TEM) observations have revealed well-preserved bundles of filamentous and tubular structured microbial remains closely resembling both modern-day and more ancient microbial forms documented from sea floor hydrothermal environments. Total organic carbon (TOC) has a range of <1.0 to 2.3 %, while the thermal maturity (%Ro) of the filamentous bundles points to maximum temperatures since deposition of around 90–100 °C, a factor that has enabled the preservation of their morphology. These results are suggestive of a well-developed Archaean sediment-hosted microbial community, situated within a basinal environment associated with an active centre of seafloor hydrothermal activity. The majority of the CM isolated from drillcore samples of the second locality, the 3.46 Ga Salgash Subgroup, a lower member of the Apex Basalt, also appears as in situ, bedding parallel bands intercalated with foliated altered argillaceous sandstone beds. TOC of the samples ranges from 1.25 to 11.48 %, while carbon content varies from 2.05 to 32.17 %. δ13C results are relatively heavy, varying from -30.4 to -22.5 ‰. Thermal maturity indicators of 10-13 %Ro suggest the CM having been subjected to temperatures greater than normally obtained from processes associated with burial. Electron paramagnetic resonance (EPR) results showed this CM in a highly ordered graphitic state. Optically, the graphite lacks the typical pronounced anisotropy characterising graphites in metamorphic terranes. Graphitisation therefore, is likely the result of rapid heating at very high temperature. HRTEM of this material revealed an extremely high level of molecular ordering contemporaneous with the presence of the C60 fullerene molecules within carbon nanotubes. These forms are a key to the distinction between biologically and abiotically synthesized CM, both by their small size and their resistance to thermal degradation. The occurrence of these carbon forms in terrestrial deposits is rare, and usually associated with wildfires, lighting strike or meteoritic impact. In the case of the Salgash CM, the formation of these molecules and the isotropic graphitised state of the CM is interpreted as a result of emplacement under pressure of very high temperature (komatiitic/ peridotite) lavas. The thermal overprint of the CM by such a high temperature process resulted in the volatilisation of the organic material, destruction of any primary biological morphology and the subsequent reorganisation of the residual CM, resulting in increased molecular ordering. In the third part of the study, CM isolated from drillcore samples of the ca. 3.5 Ga Dresser Formation bedded black chert-barite units, occurs in both dispersed and layered forms, interlayered with fine-grained silica. The intimate association of the CM and silica strongly resembles silicified microbial colonies from active hydrothermal systems, which have been previously proposed as analogues of Archaean hydrothermal sites. Isotopically light δ13C values from -38.2 to -32.1 ‰, and the association of C, H, and N, are highly indicative of a biological origin for the material. Palaeotemperatures calculated from δ18O isotope analysis of quartz chips indicate a depositional temperature for the hydrothermal veins ranging from ~120 °C to ~200 °C. 207Pb-206Pb isotope analyses conducted on pyrites extracted from the interbedded barite units reveal a dual MORB and Erosion mix source for the Pb, which gives an average 207Pb/206Pb age of 3531±42 Ma for the deposit. Ro measurements reveal four distinct CM populations, defined as ACM, A1CM, BCM, and CCM, which represent temperatures ranging from 170 °C to potentially >400 °C. TEM and HRTEM observations of the lower temperature CM population show morphological entities strongly suggestive of microbial remains, including possible cell wall remnants. Higher Ro rank CM commonly fills or coats mineral grains and lacks distinguishable structures, which is consistent with an increased thermal degradation /hydrothermal overprint. The geological setting and mineralogy of the Dresser Formation endorse its formational history as a silica-barite dominated seafloor hydrothermal deposit, most likely analogous to modern “white smokers”. The occurrence of the predominant CM (type ACM) in more or less continuous bands and laminae within the sedimentary rocks suggest an in situ, syndepositional source for the majority of this material, whereas the dispersed nature of type BCM particles indicates a recycled nature. The occurrence of type CCM within fluid inclusions gives an insight into the primary morphology of the non-degraded original microbial cells that may have existed at that time. These observations, combined with the carbon isotopic heterogeneity and fractionations are suggestive of chemosynthetic microbes occupying a seafloor hydrothermal system where rapid silicification at relatively low temperature preserved the CM. Finally, in an effort to further understand the CM structures observed in the rocks of the Dresser Formation in the context of present day microbial colonies in similar environments, a comparative morphological study was conducted using a potential modern analogue derived from an active seafloor hydrothermal environment. Such methodology utilises the standard classification used in biological species identification, which is initially based on visual identification of specific features, whether by the naked eye, light microscopy or electron microscopy. The extant hyperthermophilic microbe Methanocaldococcus jannaschii was cultured under conditions similar to the Archaean seafloor, simulating an increased thermal maturity by artificially induced autoclaving at 100 °C (1 atm) and 132 °C (2 atm). A striking resemblance to the early Archaean forms observed in the Dresser CM was evident in both wall structure and thermal degradation mode of the cultured microbe. Cell disintegration of the cultures occurred at 100 °C marking the limits of life, whereas complete disintegration, deformation and shrinkage of the cells occurred at 132 °C. These comparative observations present as a feasible way of understanding the structural features in CM identified in Archaean sedimentary packages.

An outline of the Flynn-Chabauty method for curves of genus 2 with an application to the curve C : y2 = x5 − 2x

Freiberg, Tristan (Tristan Munro) — 2008-11-21T00:00:00Z

A NOVEL AND COST-EFFECTIVE UNDERWATER WIRELESS COMMUNICATION TECHNIQUE FOR SENSOR NETWORKS.

Umberto Cella — 2010-02-19T00:00:00Z

abstract: This thesis presents a novel, thorough approach to the application of low frequency electromagnetic (EM) wave wireless communication in marine environment. This investigation is both theoretical and experimental, and is oriented towards marine sensor network applications. Different solutions within the underwater low frequency EM communication area are compared on the basis of their feasibility and practicality, especially in relation to scientific environmental monitoring applications. As a result, this thesis gathers a coordinated series of application oriented analyses of devices, such as antennas, transmitters, receivers, and of propagation issues, like signal attenuation and antenna positioning. The concluding step in this analysis is constituted by experimental field tests. As a final outcome, this works provides facts, guidelines and prototype designs related to the application of EM communication in shallow water environment, and demonstrates this communication technique is convenient for shallow water sensor networks implementation. The process followed in this analysis starts from practical considerations regarding the characteristics required by scientific equipment used in environmental monitoring. A case study is presented where a hybrid (partially wired) marine sensor network is deployed in Moreton Bay, Queensland. Strengths and weaknesses of this system are analysed, and, based on this experience, new requirements and constraints are set for a prospective improved fully wireless sensor network. In particular, the shallow water marine environment is recognized as the most likely target for scientific investigation because of its biological, economical and social importance. Firstly, various underwater communication techniques are analysed and compared. This is done on the basis of two factors: the first one is the final use of the sensor network, and the second one is the peculiar nature of the shallow water marine environment. From this analysis, it emerges that EM communication may be, in the shallow water environment, a viable and good alternative to acoustic- and optical-based techniques. From this point on, this work is aimed to prove this possibility. The next step undertaken is the theoretical analysis of EM propagation in the shallow water environment, which is modelled as a stratified lossy dielectric. The outcome of theoretical calculations is that, within a certain distance, and for a given transmitter power, low frequency EM waves are a communication channel exploitable by underwater wireless sensor networks. This is particularly true when the required data rate is low, as it is in the case of monitoring variables such as temperatures or concentrations of dissolved substances in the sea. Following this, the electric dipole and the loop antenna are studied and compared when immersed in a lossy medium such as seawater. In particular, the comparison is drawn in terms of antenna size, with absorbed power and radiated field level held equal. This, together with other practical considerations, allows the choice of the electric dipole – with some variations with respect to free space applications – as the preferred transmitting and receiving antenna. Theoretical results are verified and completed by simulations, and final prototype design guidelines are presented, together with best deployment practice suggestions. Finally, measurements are conducted in order to verify the previous calculations and considerations. In addition to them, a sensor network prototype that uses EM underwater communication is presented and tested. The field tests verify, in a real situation and at several frequencies, the maximum distance coverable with a 100 mW power source. Moreover, the same test is also conducted in fresh water, and results are compared. The instruments used for the measurements are thoroughly described, as it is the wireless sensor prototype presented. The main feature of this design is its simplicity, demonstrating that shallow water EM communication is easily achievable and that it meets the standards required by a local area marine sensor network. It can be concluded that this work offers a thorough theoretical analysis of EM propagation in shallow water environment: in parallel with this, a synthesis of practical issues that are encountered in the design of EM communication devices for underwater sensor networks is also presented. In particular, EM underwater propagation, antennas, transmitters and receiver circuits and deployment issues are thoroughly covered. Aspects such as the application of advanced signal modulations and communication protocols, however, are intentionally left open to further investigation. In fact, the range of research topics opened by this work is very wide, and they could not be all covered within this work: they span from energy harvesting to communication protocols, from antenna design to power management. All these areas are well covered by literature for terrestrial sensor networks, but they are not covered for underwater sensor networks that use EM communication: these latter are, in fact, a novelty by themselves. The problems related to this particular application have been, therefore, thoroughly exposed and opened to future research.

A novel liposaccharide system for the delivery of endomorphin-1 across the blood-brain barrier

Koda, Yasuko — 2008-11-21T00:00:00Z

The endogenous opioid peptide endomorphin-1 (Endo-1; Tyr-Pro-Trp-Phe-NH2) was isolated from mammalian brain tissue by Zadina et.al. in 1997. This naturally occurring peptide exhibits high selectivity and affinity for the µ-opioid receptor and its efficacy as a µ-opioid agonist has been shown in vivo and in vitro as similar to or higher than that of morphine. The ability to use these endogenous opioid ligands as biologically available pain relief could redefine pain management by offering potent analgesia with potentially minimal side effects. However, the significant therapeutic potential of endogenous opioid peptides is hampered by their poor metabolic stability and permeability cross the blood-brain barrier (BBB) and gastrointestinal (GI) tract in the case of oral administration. In order to improve bioavailability, chemical modifications of Endo-1 bearing a variety of lipids and sugars at the N-/C-terminus and unique peptides incorporating 2',6'- dimethyl-L-tyrosine (DMT) in place of the Tyr residue of Endo-1 were designed and synthesized. These analogues were evaluated for bioavailability using Caco-2 cells and pharmacological efficacy using SH-SY5Y cells in in vitro studies. The most promising compound was selected for in vivo biodistribution studies which were performed using intra venous (i.v.) injection and oral administration in adult male Sprague-Dawley (S.D.) rats. All results were compared to the native peptide Endo-1. Enzymatic stability assays using Caco-2 cell homogenates showed lipoamino acids and glucose succinate conjugated at N-terminus of Endo-1 analogues exhibited great stability with approximately 5-15 fold longer half lives than Endo-1 (t1/2=5.5 minutes). The stable in metabolic enzymes, lipophilic analogue C8-lipoamino acid conjugate (C8Laa-Endo-1) exhibited high apparent permeability (Papp= 3.54 × 10-6 cm/s) through Caco-2 cell monolayers. Conjugates with increased alkyl chain length Laas (carbon atom number of C12 and C18) conjugated to Endo-1 exhibited poor solubility, thus C12Laa-Endo-1 was subjected to various formulation studies achieving 87% liposome encapsulation using hydration of freeze-dried monophase method of preparation. Liposome formulated C12Laa-Endo-1 showed improved water solubility and exhibited significant enzymatic stability and high permeability. Chemically modified Endo-1 analogues were also assessed for opioid receptor binding affinity and functional efficacy using human neuroblastoma SH-SY5Y cells that express µ- and s-opioid receptors. Modification of the C-terminus of Endo-1 caused a severe drop in affinity for the µ- and s-opioid receptors, whereas N-terminal modified compounds exhibited small decreases in affinity. Analogues bearing both DMT and C8Laa conjugated at N-terminus exhibited 20-25 fold greater binding affinity than the native peptide Endo-1. The rank order of inhibition of forskolin-stimulated c-AMP accumulation was similar to receptor binding affinities. The IC50 of (DMT)1-Endo-1 and C8Laa-(DMT)1-Endo-1 was 0.43 and 0.32 nM respectively compared to 14 nM for Endo-1. The substitution of DMT in the place of Tyr residue exhibits great enhancement of these opioid activities. An in vivo study of the biodistribution of C8Laa-Endo-1 was carried out with i.v. injection and oral administration. The distribution study required N-terminal [3H]- acetylation of both Endo-1 as control and C8Laa-Endo-1. A variety of organs were taken at certain time points (15, 30 and 60 minutes) and the [3H] levels measured. C8Laa-Endo-1 showed approximately 10% uptake in the brain at 15 minutes post i.v. injection. After oral administration, C8Laa-Endo-1 accumulated in the small intestine more than Endo-1. Endo-1 was observed more in the liver than C8Laa-Endo-1 over experimental time points following i.v. injection and oral administration suggesting that Endo-1 may be metabolized via first pass metabolism in the liver. In conclusion, N-terminal modifications improved enzymatic stability and cell monolayer permeability in Caco-2 cells assays. Opioid agonist activities in SHSY5Ycells confirmed that an unencumbered C-terminus was essential for Endo-1 pharmacological activity. Furthermore, DMT incorporation at Tyr residue of Endo-1 enhanced opioid agonist activity.

A Novel Odour Attenuates The Physiological Effects of Chronic Stress

Peng Tjun Choy — 2011-03-25T00:00:00Z

Odours derived from plants have been used for centuries in aromatherapy for relieving stress, anxiety and depression. Most of the evidences for these remedies are anecdotal with minimal evidence based research. The aim of this study was to create an innovative stress relief odour to attenuate the physiological effects of chronic stress. Using an effective model for stress inducement, our laboratory has shown using concurrent stressors of social isolation and rat (predator) odour increases sympathetic neurotransmission in stress mice. The first part of this study, I used this model as a bioassay for stress inducement and evaluated 7 natural different plants derived green odours and various concentrations on their effects on stress where a control group (without treatment) is exposed to concurrent stressors while another group exposed to same concurrent stressors received treatment of 0.2 ml of odour sprayed onto beddings of animal cage 3 times daily for 2 weeks. Cis-3-hexen-1-ol and trans-2-hexenal are the more effective odours for attenuating effects of chronic stress. Upon completion of the first part of this project, I ranked the efficacy of these odours on their stress attenuation effects and proceed to stage two, where I used various combinations of the more effective stress relief odours and created concoctions of odours. I ranked these various odours combinations for efficacy and the most effective combination consist of three active chemical odours resulted in a novel odour PraescentTM. The third stage of this project is to investigate further the effect of Praescent on long term stress exposure. I exposed two groups of 4 weeks old postnatal inbred male BALB/c mice to concurrent stressors with one group receiving treatment of a combination of green odours, PraescentTM. Chronically stressed animals have increased levels of neurotransmitter release from the sympathetic varicosities when compared to minimal stressed animals. Stressed without treatment animals have a 105% increased in mean amplitude (131 ± 9.47 μV, n=30) compared to concurrent Praescent treated stressed animals (63.994 ± 3.75 μV, n=50; P < 0.00005). To corroborate these findings, I measured levels of stress hormone, corticosterone from plasma of these animals. Stressed animals had a significantly higher (3 times) in mean corticosterone plasma level (8.584 ng/ml, n=16) compared to concurrent Praescent treated stressed animals (2.078 ng/ml, n=14, P = 0.0329); hence Praescent has efficacious stress attenuating effects. The method of using odours to regulate the adverse effects of chronic stress is an ideal way managing stress as the olfactory system is the only sensory system that projects directly into the limbic system and the hypothalamus. The results obtained here are an important step toward human trials. We aim to use these results to further develop a novel therapeutic product for human use to combat the unwanted effects of chronic stress and reduce the prevalence of stress related illnesses. This is important not only for the individual but also for the prosperity of the nation as many of these health related cost will be reduce and productivity of the country increase.

Ant community response to management practices on rehabilitated mine sites

Elizabeth Williams — 2011-05-19T00:00:00Z

In Australia, there is a requirement to rehabilitate land altered by mining operations. The recovery of such landscapes can be long and protracted due to the often large disturbance caused by mining. It is important to monitor ecosystem recovery to ensure it is progressing towards the pre-determined end-use. In Queensland, monitoring criteria are predominantly based on vegetation, soil physico-chemical conditions and landform stability. To ensure recovery is efficient, management practices are often conducted to improve individual aspects of the rehabilitated ecosystem. These management procedures typically target vegetation parameters (such as increasing biodiversity) and can cause secondary disturbances to the system. Generally, minimal attention is paid to the impact of such secondary disturbances on other biota. Ants have been widely used as bioindicators to assess the impact of land management practices and, in particular, the rehabilitation of mine sites. However, there is limited published research on the influence of secondary disturbances on ant communities at recovering landscapes such as those presented post-mining. The question thus arises as to whether ant communities in these systems are more sensitive to subsequent management practices compared to those occurring on land not previously disturbed by mining. In this research, ant communities were examined as bioindicators of the assessment of management practices or secondary disturbances on two rehabilitated mines. Firstly, at a rehabilitated sand mine on North Stradbroke Island, the differences between ant communities at sites subjected to clearing, prescribed burning and/or wildfire were studied. Unmined habitats were also examined to determine whether the post-rehabilitation disturbances were facilitating ant succession to a composition similar to that in surrounding natural areas. Data from approximately two years after the last secondary disturbance showed that these sites contained a simple ant community composed primarily of non-specialised species, typical of disturbed but unmined habitats. Despite this basic community structure, many specialist and late successional ants were also present. Data collected at three years post-disturbance showed that ant composition at managed rehabilitation sites increased in similarity to the unmanaged rehabilitation site, suggesting the impacts of the management practices were short-term. Regardless of this, multivariate analyses indicated that the ant communities in the rehabilitation areas remained substantially different to those in the unmined native habitat. Therefore, the various management practices imposed did not facilitate convergence to the native ant composition. This may be because not enough time has elapsed since rehabilitation or it may be due to differences in vegetation composition and habitat structure. It is recognised that it may be unrealistic to assume that ant communities at the rehabilitated sites will converge with those in unmined areas due to the intrinsic nature of the biophysical alterations resulting from mining. At a second location in central Queensland (Norwich Park Coal Mine), the ant communities on rehabilitated pastures with different grazing histories were investigated and compared to the ant fauna of nearby unmined sites. Results showed that there was minimal disparity in the ant characteristics assessed between rehabilitated pasture with no, low, medium and high levels of cattle grazing. However, the cattle had been removed from paddocks approximately two years prior to ant sampling, possibly allowing sufficient time for both vegetation and ant communities to restructure. A rehabilitated pasture that had continuous very low grazing up until ant sampling, showed a composition similar to the other rehabilitation sites, but with additional species that were otherwise found only at the unmined reference sites. Analysis of vegetation and habitat variables suggested that the composition of ants was influenced by the cover of sward-forming grasses, particularly buffel. Such cover decreased the amount of bare ground and insolation (affecting thermophilic species) and increased vegetation complexity at ground level (influencing mobility of large species). Habitat alterations created by management practices are suggested to be the primary influence on the ant fauna examined in this research. Ant composition was shaped by habitat structure at both ground level and in the mid- to upperstorey, a response similar to that often observed following disturbances on unmined land. This may indicate that the ant communities in the studied post-mining rehabilitated areas have similar resilience to ants on unmined land subjected to the same management procedures. Additionally, trends in ant parameters were not precisely reflected in vegetation variables, suggesting that more than vegetation surveys in rehabilitation monitoring programs are required for a comprehensive understanding of rehabilitation progression and success. In addition, this thesis examined aspects of ant sampling methodology. Although there has been a call for standardisation for many years, this has not been successfully achieved. Therefore, a component of this project included an extensive literature review and evaluation of sampling methods, leading to recommendations for future standardisation. A methodology trial to determine an appropriate density and sample size of pitfall traps was also conducted. The resulting methodological and procedural advancements provided by this body of work should validate the need to foster greater attention on improving the efficiency and accuracy of ant research.

Antecedents and Consequences of Customer Affect in Collective Hedonic Services

Sandy Ng — 2008-06-27T00:00:00Z

Antecedents of Trust and Collaboration within the Context of Cultural Route Tourism

Zhuo Wang — 2011-08-23T00:00:00Z

This research aims to provide a basis for understanding stakeholder collaboration in a context of cultural route tourism (CRT) and further for guiding regional tourism planning practice in CRT related areas. In order to do this, trust is adopted as an important factor that can reduce uncertainty (Bouncken, 2000) and ‘lubricate stakeholders’ collaboration’ (Putnam, Leonardi, & Nanetti, 1993, p. 171). A conceptual framework of antecedents of trust based on Mayer, Davis and Schoorman’s (1995) is developed, which aims to test the main research question: How does trust affect the collaboration between stakeholders within a CRT context? The existing literature concerning trust focuses on interpersonal trust from a dyadic perspective, where the trustor and trustee are the two engaged parties. Dyadic trust, is a fundamental basis for all types of trust (Whitener, Brodt, Korsgaard, & Werner, 1998), and is based on a rational choice model of behaviour (Burt & Knez, 2006, p. 229). However, it has limitations on dealing with social situations where social and environmental factors might exert trust pairs. The conceptual framework developed in this research is an extended model of trust based on stakeholder and collaboration theories. From a stakeholder theory, the issues of identification and salience are highlighted and then applied to identify the research subject(s) – the relevant stakeholders in CRT (Mitchell, Agle, & Wood, 1997). Collaboration theory provides the determinants of successful collaboration (Blumenberg, 2002). Trust is then highlighted as prominent factor that joints stakeholders through their collaboration. Based on the analysis of dyadic mechanism of trust, the propensity to trust, trustee’s trustworthiness, and social identity are then examined as the major antecedents of trust in a CRT context. The objective of this research is to apply a trust-collaboration model in a CRT context. An interpretive social science paradigm and a case study using qualitative data collection are adopted. Dali and Lijiang, covering a section of the Tea Horse Route (THR), are selected as the case area in which to conduct semi-structured interview. All the evidence was recorded, transcribed and analysed with use of Nvivo software. The results indicate that collaboration among micro tourism enterprises is a prominent phenomenon along the THR, where stakeholders are connected and facilitated their collaboration by trust relationships. The trustor’s propensity to trust provides a general willingness of a trustor, which is the prerequisite of trust formulation. Trustee’s trustworthiness can be examined from their ability, benevolence, integrity, and social identity. Social identity is a new antecedent of trust that is identified by this research and supported by the evidence, which can be accessed both from a trustor and trustee perspective, and an important facilitator towards stakeholders’ collaboration. The proposed extended conceptual framework is confirmed to be applicable in a CRT context, specifically in a regional planning area. It provides a framework for further research of stakeholder collaboration and regional tourism planning in a large scale of a cultural route context. However, the data obtained by the researcher are only from a sector of a THR context in a tourism development stage. As a result, the conceptual framework should be considered for further testing and evaluation.

Antennas for Modern Indoor Wireless Communication Systems

Serguei Zagriatski — 2010-03-08T00:00:00Z

Recent years have witnessed a growing demand for broadband wireless communication services such as on-the-go web-browsing, high speed data transfer and streaming of high definition multimedia. In response to this growth, there has been a rapid progress in research and development of technologies supporting high-speed wireless networks offering flexibility and scalability to heterogeneous consumer requirements. A fundamental challenge to the reliable operation of a wireless communication link is the wireless channel which is influenced by time-variant noise, interference, multipath and scarcity of the available frequency spectrum. Due to the wireless nature of the signal transmission and the manner in which energy is distributed or collected, an antenna has a profound influence on an efficient operation of wireless link. Because nowadays an antenna is required to work with many wireless standards, it poses one of the most difficult design and development technological problems. In the past, many antenna designs were concentrated on conventional outdoor applications such as satellite communications, terrestrial point to point communications and cellular base stations. In these applications, the primary design goal was the antenna electrical performance. In case of indoor applications, the designer has to pay attention not only to the electrical performance but also to mechanical, environmental and aesthetic features of antenna. In this thesis, the investigations into design and development of antenna for indoor wireless communication systems that are either currently widespread or quickly entering the consumer market are carried out. First, a single band circularly polarized Radial Line Slot Array antenna covering 2.4GHz ISM frequency spectrum of IEEE 802.11b/g protocol is proposed. Then, an access point antenna for IEEE 802.11a/b/g WLAN applications operating in a dual frequency band covering 2.4GHz and 5.2GHz frequency spectra is described. It consists of a RLSA antenna and a patch antenna combined in one body. During the design stage, in addition to characteristics such as return loss, radiation pattern and polarization, attention is paid to mechanical rigidity, light weight and low visual impact of these radiating structures. A low manufacturing cost is also part of the design strategy. This is important because of competitive commercial market of WLAN applications which is sensitive to the development cost. In theoretical investigations, a Field Matching Method is utilized to achieve a first order approximation to the coaxial-to-waveguide transition forming the feeding element of the RLSA antenna. Next, the full EM analysis (HFSS™) based on Field Element Method is applied to simulate the single and dual band antennas. Both types of access point antennas are manufactured and tested. Experimental results are compared with simulation results. The next part of this thesis presents the investigations into antenna diversity techniques for a wireless communication link in an indoor environment. The design of the automated experimental testbed is presented. This testing facility is used to measure the signal strength levels of a communication link between a mobile wireless device and an access point when they are equipped with multiple element antennas (MEAs). Special attention is given to the benefits of using MEA in a rich scattering environment that is accompanied the experiment. Full design details including electrical and mechanical features are provided. For a given feeding configuration, the testbed allows for measuring the received signal strength when the receiving module is moved over a circular area in an indoor environment. First set of experiments concerns the MEA system that utilizes two single-port transceivers each equipped with either 180º or 90º 3dB hybrid. By using alternatively one of the two input ports of the hybrids to feed a pair of monopole antennas several different transmission or reception modes of the 2x2 MEA communication link are investigated. The next set of experiments focuses on the performances of an indoor wireless system which uses either linearly or circularly polarized antennas at the two sides of the communication link. The overall diversity results indicate that by marginally increasing an overall system complexity (by using simple hybrid circuits and antennas), traditional transceiver systems equipped with MEA can provide significant improvements in the quality of indoor wireless link. The final part of this thesis presents the investigations into the design of planar monopole antennas that offer good return loss and omni-directional radiation pattern characteristics over an Ultra Wide frequency Band (UWB) spanning from 3.1GHz to 10.6GHz. Two types of planar monopole antennas are investigated. First, the ring type square with semi-circular base monopole antenna placed vertically above a finite ground plane is introduced followed by its design, manufacturing and testing. The second UWB antenna which is proposed in this thesis is a printed square with semi-circular base monopole antenna. This antenna is positioned in the same plane as ground and thus offers direct integration with a front-end circuitry of wireless transceiver. Several variations of this type of antenna featuring different outlines are designed, manufactured and tested. The obtained experimental results show a good agreement with the simulation results, as accomplished with the full EM analysis and simulation software HFSS™.

Anterior-Posterior Ground Reaction Force Characteristics for Post-Block Foot Contacts in Sprint Running

Watts, Mark Charles — 2008-11-21T00:00:00Z

Past research on the acceleration phase in sprint running has concentrated on the kinematics of sprint blocks set-up and the initial steps after exiting the sprint blocks. In contrast, there has been limited research on the ground reaction forces (GRF) generated during the initial post-block foot contacts. These initial foot contacts in sprinting are important for optimising performance in the initial acceleration phase of sprinting. However, little is known about the GRF elite sprinters generate during the initial foot contacts and how these GRF characteristics relate to performance. It is the anterior-posterior (A-P) GRF that are of most importance as they indicate the sprinters motion from the start to the finish line. This thesis investigates the A-P GRF of the first two foot contacts of the sprint start after leaving the blocks. The participants included seventeen male and six female sprinters with a mean age of 22.6 (SD 4.4 years). Seventeen of the sprinters had competed at international/national level competitions and six at recreational/amateur level competitions. The athletes were classified as senior male elite (SME), senior female elite (SFE), junior male elite (JME) and senior male recreational (SMR). The sprinters were instructed to perform block starts at maximal effort to produce the fastest time over 5 metres on a 30 metre indoor laboratory track. Timing gates were used to record 5 metre times and two strain gauge force plates were placed in series to collect GRF data from the first two foot contacts after leaving the starting blocks. From the GRF data, braking time, maximum A-P braking force, A-P braking impulse, propulsive time, maximum A-P propulsive force, A-P propulsive impulse and A-P contact impulse were determined for each trial. The A-P propulsive phase constituted greater than 90% of the total contact time, had approximately twice the magnitude of the maximum force of the braking phase and accounted for more than 95% of the total contact impulse across the four groups of sprinters. The SME group produced a significantly larger A-P propulsive impulse on the first and second steps compared to the SFE (p less than 0.05 and p less than 0.05 respectively), JME (not significant and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME groups maximum A-P propulsive force was significantly larger on the first and second steps than the SFE (p less than 0.05 and p less than 0.05 respectively), JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The SME groups propulsive time on the first and second steps was not significantly different compared to the SFE (both not significant) but was significantly shorter compared to the JME (p less than 0.05 and p less than 0.05 respectively) and SMR (p less than 0.05 and p less than 0.05 respectively) groups. The maximum A-P propulsive force correlated strongly with 5 metre time for the first step (rs = -0.670, p less than 0.01), second step (rs = -0.621, p less than 0.01) and the addition of the first and second steps (rs = -0.678, p less than 0.01) across all the sprinters. Whereas, the A-P propulsive impulse correlated strongly with 5 metre time for the first step (rs = -0.525, p less than 0.01), second step (rs = -0.592, p less than 0.01) and the addition of the first and second steps (rs = -0.584, p less than 0.01). Three A-P GRF patterns were observed during the first and second foot contacts of the sprinters examined in this study. A braking-propulsive (B-P) pattern was the most frequently observed followed by a propulsive-braking-propulsive (P-B-P) and a no braking (NB) pattern 82.7%, 15.4% and 1.9% respectively. The P-B-P and NB patterns, which have not been described previously, appeared most frequently in the least experienced sprinters. In the past, some sprinters and their coaches have tried to minimise the braking phase and maximise the propulsive phase of the first two foot contacts after exiting the blocks during sprinting. This study suggests that increasing the maximum propulsive force is the best way to increase performance over the first 5 metres of the acceleration phase. The research also suggests that there will be little benefit gained from trying to increase performance by focusing on the braking phase during these first two steps after exiting the blocks. As such, sprinters and coaches should focus their attention primarily on producing a large A-P propulsive force during the first two steps of a sprint.

Antibiotics and Antibiotic Resistant Bacteria in the Aquatic Environment: A Global Issue, an Australian Perspective

Andrew Watkinson — 2008-06-12T00:00:00Z

Anticipating the future:Today’s solutions, tomorrow’s problems? A case study exploring the capacity of institutional responses to complex environmental problems to achieve their objectives

Rachel Greenfield — 2009-11-03T00:00:00Z

Over time the impact of human interactions upon the natural environment has revealed changes to the condition and structure of the landscape. Practices which were once deemed to be suitable to natural conditions have since been recognised as having caused degradation to land, water, soils, and impacted upon floral and faunal biodiversity. In response to evidence of ecological declines, a range of institutional and management responses have been implemented, evolving to become a complex and fragmented environmental legal and management system. The purpose of this study was to examine the effectiveness of institutional responses as solutions to environmental problems. It did this through a case study exploration of the development, implementation, and administration of regulatory changes to the management of native vegetation in Queensland. These reforms were introduced to meet electoral commitments to address the high land clearing rates in light of scientific evidence of the association between this activity and the symptoms of degradation. Specifically, the study investigated whether these reforms would achieve their designed objectives without perverse impacts upon the ecological, economic, or social sustainability in semi-arid rangelands of south-west Queensland. The Pressure-State-Response (PSR)/ Driving Force-Pressure-State-Impact-Response (DPSIR) Models and the principles of Ecologically Sustainable Development (ESD) provided the foundation for the formation of the case study research questions to examine this complex real world environmental problem, and the attempts made to achieve its resolution. These questions focused upon each element of the Models. Hence, five research questions guided this investigation: 1. What is the condition of the environment in south-west Queensland? 2. What are the major pressures upon the condition of the environment? 3. How effectively have institutional responses to address the environmental problem been implemented? 4. What are the social, economic, and environmental impacts of the response in the case study region? 5. Was the response designed to maximise its potential effectiveness without unintended consequences (impacts)? Five research cycles were employed to gather and verify data required to explore these questions. Firstly, published knowledge, science, and best-practice approaches to decision making were highlighted through literature examinations. Focus groups then identified priority issues for further exploration. Interviews facilitated the in-depth investigation of problems and the testing of assumptions. Practical and on-ground conditions, practices, and issues were subsequently detailed in ethnographic studies, and emerging research and system changes reviews presented the context to the matters being explored. Through this process of data collection, triangulation, and verification, collectively, this case study investigation found that: • despite extensive research and investment into science and knowledge, environmental problems in the case study area persist, due to the combined impacts of natural and induced pressures; • the introduction of domestic grazing and permanent waters into an area ill-equipped to handle it led to the transformation of the semi-arid landscape, whilst the changes which have become apparent have been attempted to be resolved by the landholders who inherited them; • the on-ground responses to degradation are influenced by an evolving, multifaceted, and multi-jurisdictional framework of policies, laws, and strategies which comprise the environmental legal system, and are implemented at international, national, jurisdictional, local, and property levels; • Queensland’s native vegetation framework is one of the more recent additions to this system, and whilst well intended, its design and implementation has been criticised as poorly reflecting best practice approaches; • regulatory deficiencies have the potential to limit the effectiveness of native vegetation reforms and the achievement of desired legislated objectives, and have the potential to compounding environmental, social, and economic problems in the case study region. However, it is argued that had a best practice approach to institutional response design and implementation been followed, this would have provided the opportunity to anticipate future problems, and allowed them to be addressed through the development and implementation of complementary tools and strategies. Furthermore, where institutional responses anticipate and address perversities as they occur, this can ensure that potential solutions to complex problems are capable of maximising the achievement of desired objectives without unacceptable impacts. Consequently, in order to identify and prevent the undesired outcomes predicted for the case study region, and to maximise the effectiveness of policy and institutional responses, problems need to be correctly defined, and appropriate responses generated. Hence, the thesis is: Where institutional reforms to solve environmental problems are not designed,implemented, and administered effectively, they will create negative ecological,economic, and social impacts. Policy design must be capable of conceptualizing and responding to possible and probable outcomes. However, and despite the knowledge, science, and information to do this already being available to guide decision making processes, the exploration of the case study demonstrated that institutional responses can still be potentially ineffective. This may be due to the complexity of issues needing to be considered, and the lack of guiding processes and tools to assist decision makers undertake this multidisciplinary activity. To resolve this dilemma, an adapted model has been created. The “Anticipatory, Sustainable, and Precautionary Institutional Response Evaluation (ASPIRE) Model” incorporates the findings and lessons from this study, and the elements which need to be considered in decision making. Through the utilisation of this model as a framework for examining complex problems, and developing and evaluating proposed solutions, the replication of the negative and perverse impacts of institutional responses which are anticipated for the case study can be prevented in the future. This will be achieved where the model is utilised by decision makers to guide the process for policy development and solution design in all sectors which attempt to address complex problems in multifaceted management environments.

Antifungal pharmacodynamic relationships in experimental invasive candidiasis and invasive aspergillosis: implications for antifungal therapy

Hope, William Winima Denbeigh — 2008-11-21T00:00:00Z

Invasive candidiasis and invasive aspergillosis are both leading causes of morbidity and mortality in immunocompromised patients. Pharmacodynamics is the study of concentration-effect relationships. In recent years, there have been significant advances in the pharmacodynamics of antibacterial and antiviral agents. In contrast, less is known about the pharmacodynamics of antifungal agents. This thesis examines the pharmacodynamic relationships of antifungal agents for invasive candidiasis and invasive aspergillosis as a means for studying a range of clinically relevant questions which are difficult to resolve using other experimental platforms. The common themes are as follows: (1) the development of novel experimental pharmacodynamic models are required for an understanding of concentration-effect relationships; (2) innate immunological effectors, in combination with antifungal agents play a crucial role in determining the outcome of invasive fungal infections; (3) a delay in the administration of antifungal agents is potentially detrimental to the host; (4) critical events in the invasion of Candida spp. and Aspergillus spp. occur within the initial 24 hour period post infection; (5) mathematical models can be used to further understand and predict system behavior; and (6) population pharmacokinetics and Monte Carlo simulation provide a mechanism to further explore the clinical implications of experimental data. An introduction to the microbiology and pathogenesis of invasive fungal infections, along with the pharmacology of antifungal agents and modeling techniques used are reviewed in Chapter 1. The pharmacodynamic models of invasive candidiasis, developed in Chapter 2, which were then used to study: (1) the antifungal effect of neutrophils, and (2) the effect of a delay in the administration of antifungal agents on the exposure-response relationships. The findings were placed in a pathological context, by defining the histological appearances in the kidney. These studies demonstrated that neutrophils exerted a significant antifungal effect independent of antifungal agents. The antifungal effect of neutrophils was quantified using a mathematical model. A progressive delay in the administration of antifungal agents resulted in a diminishing antifungal effect. The data underscores the importance of adequate numbers of neutrophils and the administration of antifungal agents at the earliest possible point in time to maximize the probability of a favorable therapeutic outcome. Chapter 3 investigates the utility of combining the antifungal agents amphotericin B and 5- fluorocytosine (5FC) for the treatment of invasive candidiasis. Using a surface response methodology, the combination was shown to be additive. The clinical implications of this finding were explored using population pharmacokinetics and Monte Carlo simulation; this approach showed that the currently recommended dosage of 5FC is significantly in excess of that required to produce near maximal effect, and therefore unnecessarily exposes recipients to the risk of drug related toxicity. In Chapter 4, a unique molecular mechanism of resistance of C. albicans to 5FC was defined. In Chapter 5, a definition of a drug-exposure breakpoint for 5FC was sought (i.e. a value which separates individuals into groups with a satisfactory versus a suboptimal outcome), and the clinical implications of this finding were explored. Isolates in which the molecular mechanism of 5FC resistance had been defined in Chapter 4, were used. These experimental data were then bridged to humans to predict a susceptibility breakpoint of 5FC. Chapter 6 represents a synthesis of all of the skills acquired in previous chapters, to develop a novel in vitro model of the human alveolus. This model was used to study the pathogenesis of early invasive pulmonary aspergillosis, and the pharmacodynamic relationships of amphotericin B against A. fumigatus. A long standing problem related to the measurement of the residual Aspergillus burden following antifungal therapy was resolved with the use of the Aspergillus cell-wall antigen, galactomannan. The invasion of Aspergillus was studied using confocal microscopy and an A. fumigatus transformant expressing green fluorescent protein. The growth of Aspergillus could not be suppressed with antifungal drugs alone; rather, a combination of amphotericin B and macrophages was required to suppress growth. A large mathematical model was developed to define the concentration of amphotericin B and number of macrophages required to suppress fungal growth. The clinical implications of the experimental data were explored using population pharmacokinetics and Monte Carlo simulation. In the concluding chapter, the advantages of a pharmacodynamic approach and the future challenges are discussed.

Antigenic, genetic and biological characterization of the flavivirus Alfuy.

May, Fiona J. — 2008-11-21T00:00:00Z

Alfuy virus (ALFV) is a member of the Japanese encephalitis virus (JEV) antigenic complex of flaviviruses and is currently classified as a subtype of Murray Valley encephalitis virus (MVEV). However, while MVEV and JEV pose significant health risks to regions of Northern Australia, there is little evidence that ALFV causes disease in humans or other animals. Due to the apparent low pathogenicity of ALFV, few studies have previously focused on this virus, therefore, very little is known about it. This thesis aims to improve our understanding of this virus, with the potential of using ALFV, or markers of attenuation discovered within its genome, to develop novel vaccines for use against MVEV, JEV, and even other members of the Flavivirus genus. Previously, nucleotide sequence analysis of a small portion of the genome of ALFV was used to reclassify the virus as a subtype of MVEV. During this project the entire genome of ALFV was sequenced and compared with other members of the genus. Phylogenetic relationships revealed that although ALFV is closely related to MVEV, it is no closer to MVEV than to JEV or to Usutu virus, suggesting that ALFV should not be classed as a subtype of MVEV. Indeed, antigenic studies comparing ALFV, MVEV and JEV, using mAbs produced to MVEV, show a distinct antigenic profile for ALFV. Several unique genetic markers that may affect the virulence of ALFV were observed in the genome. Within the envelope (E) protein, the conserved Nlinked glycosylation motif contained a substitution causing a loss of glycosylation. Also within the E protein, the hinge region, involved in low-pH dependent conformational changes in the protein, also showed several amino acid differences when compared with MVEV and other related viruses. In addition, the highly conserved terminal dinucleotide was deleted. This region is thought to be important for replication of viral RNA. Virulence studies of different strains of ALFV in three-week old Swiss outbred mice also show a different pattern of virulence to MVEV. While MVEV is highly neurovirulent and neuroinvasive in these animals, ALFV exhibits weak neuroinvasiveness, producing very little disease in mice infected intraperitoneally, and producing ALFV-specific antibody only in mice infected with high doses. Even in the highly susceptible IFN-alphaR-/- mice (deficient in the receptor for interferon-alpha), ALFV caused significantly delayed mortality. This data suggests that ALFV is inefficient at replicating in the periphery of these animals. ALFV also exhibited a different tropism to MVEV in vitro, showing significantly reduced replication in Vero cells, a line of African Green Monkey kidney cells that supports efficient replication of all other members of the JEV complex. Binding studies showed that ALFV was able to bind to the surface of these cells, but electroporation of viral RNA directly into the cytoplasm was unable to initiate infection, suggesting inefficient replication or translation of ALFV viral RNA in this cell type. To determine the motifs responsible for these unique phenotypic characteristics of ALFV, three chimeric viruses were engineered based on a previously constructed infectious clone of MVEV. One, containing the structural (prM and E) genes of ALFV in the MVEV backbone, exhibited weak neuroinvasiveness, similar to ALFV, but unlike ALFV, was able to replicate efficiently in Vero cells, and produced ALFVspecific antibody in mice infected with low viral doses. This suggests that the structural genes of ALFV are associated with poor neuroinvasion, but are not responsible for poor extraneural replication in mice, or lack of growth in Vero cells. Another mutant virus was constructed by deleting the terminal dinucleotide in the MVEV infectious clone. This clone spontaneously reverted to the wild type sequence, preventing phenotypic analysis of this mutation. The final chimera contained the nonstructural genes of ALFV with the structural genes and the UTRs of MVEV. Unfortunately, despite several attempts, this clone was unstable in the bacterial host, and insertions or deletions were spontaneously introduced into the genome. Based on phylogenetic, antigenic and virulence data, ALFV is sufficiently different from MVEV to be classified as a separate virus within the genus. Determinants of the low neuroinvasiveness of ALFV have been localized to the structural genes of ALFV, probably within the hinge region of E, and/or due to the lack of glycosylation of the E protein. The cause of the delayed growth in Vero cells was unable to be determined, but is not due to a motif within the structural genes.

Antigen Presentation and Inflammation in Allogeneic Bone Marrow Transplantation

Kate Ann Markey — 2011-07-05T00:00:00Z

Allogeneic bone marrow transplantation (BMT) is utilised as a curative therapy for haematological malignancies, predominantly leukaemia. The curative benefit of BMT lies in the graft-versus-leukaemia (GVL) effect, in which residual leukaemic cells are recognised by the incoming donor immune system and targeted for elimination via immunological means. Allogeneic BMT is however complicated by a high procedure-related mortality, with post-BMT death occurring due to relapse, infection and graft-versus-host disease (GVHD). GVHD develops to some extent in the majority (50-70%) of allogeneic BMT recipients and results in widespread immunological damage to host tissue, mediated by T and NK cells in the donor graft, as well as by inflammatory cytokines (e.g. TNF, IL-1). There are three key phases in GVHD pathogenesis: 1) initial host tissue damage secondary to pre-transplant conditioning which leads to an initial release of pro-inflammatory cytokines; 2) activation of donor T cells in the graft by both host and donor antigen presenting cells; and 3) the expansion of effector donor T cells and intensification of the inflammatory cytokine response. My work has focused on both the inflammatory cytokine and antigen presentation aspects of GVHD following BMT. Hypotheses: Lymphotoxin alpha, a member of the TNF superfamily of signalling molecules, contributes to GVHD pathology TNF is well established as one of the key pathogenic cytokines in GVHD, and thus it was hypothesised that the related cytokine, lymphotoxin alpha, which signals through the same two receptors, would also contribute to GVHD. Using mouse models of GVHD, I was able to confirm that lymphotoxin alpha is indeed a critically important molecule in GVHD pathology, inducing apoptosis within recipient gastrointestinal tract and skin. This is a clinically important finding, as TNF blockade is now part of standard GVHD therapy, but some agents (e.g. Infliximab) block only TNF, whereas others inhibit both TNF and soluble lymphotoxin (e.g. Etanercept). Recipient plasmacytoid DC do not play a role in the initiation of GVHD Studies defining the role of antigen presenting cell (APC) subsets in both host and donor-mediated antigen presentation have been extremely limited to date. Previous studies within this laboratory sought to clarify the role of plasmacytoid dendritic cells (pDC) and established that host pDC were exquisitely sensitive to radiation and largely absent by the time donor grafts were transferred and that donor pDC fail to mature during GVHD, due to developmental arrest at the “pre-DC” stage. Based on this knowledge, I sought to further examine the role of recipient pDC in the initiation of T cell responses, and confirmed that they were highly unlikely to contribute to the priming of alloreactive T cells after BMT. Subsets of donor APC play differential roles in alloantigen presentation To assess the relative contribution of different APC subsets to alloantigen presentation, transplants were performed using the C57Bl/6 → BALB/c model of allogeneic BMT. Using this system, the TEa transgenic T cell could be used to measure alloantigen presentation, as the TEa has a T cell receptor (TCR) specific for a host-derived peptide presented in the context of donor MHC II molecule. Following transplantation, APC subsets were systematically removed using conditional depletion methods (i.e. CD11c.DTR for cDC, MAFIA donors for macrophages and cDC) and monoclonal antibodies (i.e. 120G8 mAb specific for pDC), and TEa T cells were adoptively transferred in order to quantify alloantigen presentation in the absence of each APC subset. As a result of this study, donor conventional dendritic cells (cDC) were confirmed as the critical donor APC for presenting alloantigen after BMT. GVHD-associated immune suppression occurs due to post-transplant APC dysfunction The final component of this thesis has involved the use of the experimental methods established during my PhD candidature to examine the function of the reconstituting donor immune system following BMT. This work demonstrates that donor cDC function is markedly impaired in the context of GVHD due to a defect MHC-II presentation, arising due to the absence of the CD4+ cDC subset in combination with decreased function of the double-negative (DN) cDC subset. Identifying this defect in cDC development and function during GVHD has important implications for the design of therapies to improve post-transplant immunity, and investigation of interventions to reverse this defect form the basis for ongoing work. The experimental work contained within this thesis addresses several issues; it identifies conventional dendritic cells as the key population for antigen presentation after allogeneic BMT, it confirms that the presence of GVHD after transplant induces deficits in cDC capacity to present exogenously captured antigen via the MHC II pathway, and it provides evidence that lymphotoxin is an important and previously unrecognised pathogenic cytokine in GVHD. These aspects of transplant immunology were previously unreported, and form platforms for new therapeutic interventions to modulate transplant outcome.

Antimicrobial Resistance Mechanisms in Canine Multidrug-Resistant Escherichia coli and Enterobacter spp.

Sidjabat, Hanna — 2008-11-21T00:00:00Z

Multidrug-resistant (MDR) Enterobacteriaceae exhibiting resistance to expanded-spectrum cephalosporins have recently emerged as a cause of opportunistic infections in hospitalised dogs. At the University of Queensland Veterinary Teaching Hospital (UQVTH) and other referral veterinary hospitals in Brisbane Australia, MDR E. coli (MDREC) and MDR Enterobacter spp were the most commonly isolated strains. Plasmid-mediated resistance genes and clonality were determined for 11 MDREC and 10 MDR Enterobacter spp. isolates associated with opportunistic infections in hospitalised dogs. Phenotypic (broth microdilution and disc susceptibility testing, modified disc diffusion testing and IEF for ~Iactamases) and genotypic tests (pCR and sequencing, plasmid analysis and Southern blot hybridisation, bacterial conjugation and transformation) were used to identify and localise specific antimicrobial resistance genes to plasmids. The clonality of the isolates was investigated by PFGE and plasmid analysis. MDREC isolates could be divided into two clonal groups (CG 1 and 2) with distinct PFGE and plasmid profiles. In all MDREC stmins, resistance to expanded-spectrum cephalosporins was imparted by an AmpC ~Iactamase gene, blacMY_7 which was located on a nonconjugative ~93 kb plasmid that did not contain any other known resistance genes. There was a marked difference in the distribution of plasmid-mediated resistance genes between CG 1 and CG 2. The identified resistance genes located on ~170 kb plasmid in MOREC CG 1 strains were blaTEM, catAl and class I integron-associated genes (sull and dfrA17-aadA5). In MDREC CG 2 strains, a second -93 kb plasmid contained biaTEM and co-transferred resistance to sulfonamide/trimethoprim, tetracycline and streptomycin. This plasmid also contained a class I integron, but the gene cassette could not be identified, except for the presence of dfrV in a single isolate. Canine MDR Enterobacter spp. clinical isolates were genotypically diverse based on PFGE; and belonged to either Enterobacter cloacae or Enterobacter hormaechei based on 16S rRNA gene sequence analysis. Of the ten canine Enterobacter spp., nine isolates carried plasmid-mediated blasHv.12 on -140 kb plasmid and the remaining one isolate possessed blacMY_2 on a ~93 kb plasmid. The blasHV_12-carrying plasmid also co-transferred resistance to chloramphenicol (cauV), streptomycin/spectinomycin (aadA2), gentamicin, tetracycline, sulfonamide/trimethoprim; whereas, the blacMY.2-carrying plasmid did not contain any known resistance genes to other antimicrobials. Both blaSHV.12 and blaCM'{.2 carrying plasmids were both readily transmissible. This is the first report of plasmid-mediated blaCM'{.7 in MDREC and blaSHV'12 and blaCM¥.2 in Enterobacter spp. isolated from animals. The fact that the blaSHV.12 carrying plasmid can transfer readily and could be co-selected by several traditional antimicrobials provides an exceptional threat of rapid spread of this plasmid between bacteria causing extraintestinal infections in both humans and animals. In contrast, the blaCM'{'2 or blaCM'{.7 carrying plasmids will only be spread when there is selection pressure created by use of expandedspectrum cephalosporins or broad spectrum ~-Iactam/clavulanic acid combinations. A I-year infection control study was conducted to limit further occurrence of extraintestinal infections and determine the molecular epidemiology of MDREC, and, to a lesser extent, MDR Enterobacter spp. emergence and spread within UQVTH. Selective media were used to obtain MDR coliform isolates from the hospital environment and rectal swabs of hospitalised dogs and hospital employees. Furthermore, a multiplex PCR was designed to identify the MDR coliform isolates as E. coli, and to determine their clonality. A subset of representative isolates was characterised by PFGE, plasmid analysis and serotyping. Similar to the MDREC clinical cases, only two COs were identified. The clinical infections were therefore likely to be endogenous and influenced by prolonged hospitalisation periods and concurrent antimicrobial therapy. Direct, dog-to-dog, faecal-oral transmission was likely to have occurred as well as exposure to a contaminated environment for MDREC CG I and Enterobacter spp. strains. More importantly, the isolation of MDREC CG 2 from two hospital employees showed the possibility ofMDREC transfer between dogs and humans via the faecal-oral route. The clinical cases caused by MDREC and MDREC spread within hospitalised dogs and the hospital environment were therefore resultant from clonal dissemination oftwo distinct clonal lineages. A human clinical MDREC strain isolated from a Brisbane patient with a urmary tract infection Was shown to be genotypically related to MDREC CG I and possessed the same blaCMY.7 plasmid, confirming that dog-to-human, or indeed, human-to-dog MDREC transmission, can also be hypothesised for MDREC CG 1 strains. The level of blaCMY.7 RNA expression and plasmid copy number were determined for representative canine and human MDREC CG 1 and CG 2 strains. It was compared with relative expression in Salmonella enterica serotype Typhimurium (S. typhimurium) strain 100 and laboratory E. coli strains containing the native blaCMY.7 plasmid or the cloned blaCM'{.7 gene plus the transcriptional start site. The constitutive expression level per gene copy of blaCM'{.7 in canine MDREC CG 1 (-1 copy per cell) and CG 2 (-2 copies per cell) Was 100-fold and ISO-fold greater than chromosomal ampC expression in the C. freundii wild-type, respectively. The constitutive expression per copy number of cloned blaCMY.7 insert (-15 copies) was IS-fold lower than corresponding expression in both the E. coli laboratory strain containing the blacMY.7 native plasmid (-2 copies) and the original clinical donor strain. The constitutive expression data correlated with the expanded-spectrum cephalosporin MICs and high-level AmpC expression did not compromise the growth rate of E. coli. Typical ExPEC virulence genes were identified in the three human, 25 canme and 6 environmental MDREC isolates. Regardless of sample source, ExPEC VFs were distributed according to clonality and phylotype. MDREC CG 1 strains belonged to phylogenetic group A (typical commensal E. coli phylotype) and possessed only iutA and traT; whereas MDREC CG 2 were all phylogenetic group D (typical ExPEC phylotype) and possessed iutA, ibeA, fimH, and kpsAfT K5, which are important virulence genes in extraintestinal infections. The fact that MDREC CG 2 possessed type 1 :fimbriae and flagella in comparison to CG 1 isolates may contribute to colonisation ability and virulence, both in the gastrointestinal tract and extraintestinal sites, such as bladder. This is confirmed in three different mouse models (gastrointestinal colonisation, extraintestinal virulence and urinary tract infection) in which CG 1 and CG 2 index strains were compared. Both CGs of MDREC strains isolated from extraintestinal infections in dogs were not only important sources of plasmid-mediated antimicrobial resistance genes, but strong evidence was obtained supporting their ability to colonise and cause extraintestinal infection in humans. Dogs therefore represent an important reservoir of MDR coliforms that cause opportunistic infections and the transfer of strains and/or their plasmid-mediated resistance genes, particularly AmpC j3-lactamase and ESBL genes commonly occurs between humans and dogs. This finding has important public health implications and must be considered in treatment and prevention strategies in human and veterinary settings.

Anti-Petrarchism in the Sonnets of Spenser and Shakespeare

Lipke, Ian — 2008-07-03T00:00:00Z

Antipodes to Terra Australis

Avan Stallard — 2011-06-28T00:00:00Z

The idea of an imaginary southern continent persisted in European discourse for two millennia in an unbroken chain of scholarship stretching from antiquity to the cusp of modern times. The unavoidable question is what drove belief, and what compelled people to persist with the notion of a southern continent even when faced with falsifying evidence? In addressing this question I attempt to draw the historical traces together in a way that not only illuminates what people thought and what actions came from those beliefs, but also suggests how belief, desire and expectation structured the interpretation and reception of geographical data. Misconceptions about the role that theories of hemispheric balance played in the discourse of a southern continent have long obscured the more complicated interplay of geographical lore and empirical discovery with the imperial and commercial milieus of early modern Europe. To say that people believed and held onto their belief in a southern continent because they wanted it to exist is to answer the basic question addressed to all imaginative geographies – why did people believe in something that does not exist? Where I attempt to go further is in showing exactly how desire and expectation structured the entire discourse as it evolved across the centuries.

Anti-pronation tape: Initial effects on neuromotor control of gait, foot posture and foot mobility and the influence of continual use

Melinda Franettovich — 2010-03-25T00:00:00Z

Anti-pronation taping is commonly used by clinicians in the management of lower limb musculoskeletal pain and injury. Despite its frequent use in the clinical setting the mechanism(s) underlying its efficacy is not completely understood. For example, there is evidence that anti-pronation taping produces a biomechanical effect, but there has been little investigation of other mechanisms such as neurophysiological or psychological effects. Additionally, studies to date have been performed in mostly asymptomatic populations and have focused on the initial effect of tape (i.e. immediately following application and through a short duration of activity). Improved understanding of the underlying physiological mechanism(s) of anti-pronation tape is likely to facilitate improved knowledge of the technique, which may optimise its clinical application and contribute to clinical selection guidelines. The aims of this thesis were developed to address several of the limitations in the current anti-pronation taping literature. To facilitate an investigation of the comparative initial physiological effect of anti-pronation tape in a symptomatic and asymptomatic population, the first aim of this thesis was to compare neuromotor control (control of muscle activation and movement patterns) of gait, foot posture and foot mobility between asymptomatic individuals and individuals with a history of exercise related leg pain. The second aim of this thesis was to investigate the initial physiological effects of anti-pronation tape, specifically its neurophysiological (i.e. effect on muscle activation patterns) and biomechanical (i.e. effect on movement patterns, foot posture, foot mobility) effects. Thirdly this thesis aimed to investigate the duration of these initial physiological effects following tape removal. The fourth and fifth aims were to investigate the long term biomechanical and neurophysiological effects of anti-pronation taping i.e. following continual use over a clinically relevant period. In the first instance our aim was to investigate the effect of continual use on neuromotor control of gait, foot posture and foot mobility, and secondly to investigate the effect of continual use on the technique’s initial neurophysiological and biomechanical effects. Individuals with exercise related leg pain demonstrated lower activation of gluteus medius and lateral gastrocnemius during gait, but we observed no differences in lower limb movement patterns or foot posture and foot mobility between the two groups. The initial effect of tape was similar in individuals with and without exercise related leg pain. Specifically application of tape produced a reduction in activation of tibialis posterior, tibialis anterior and medial gastrocnemius, and increased activation of peroneus longus. There was a reduction in foot mobility, ankle plantarflexion and abduction excursion and an increase in ankle dorsiflexion and adduction excursion. Reduced muscle activation and increased motion was also observed at more proximal segments (knee, hip, pelvis), but were of smaller magnitude than at the foot and ankle. Changes in foot mobility, ankle kinematics and leg muscle activity did not continue following the removal of tape, but at more proximal segments (i.e. pelvis, hip and knee) small changes in kinematics and muscle activity were observed following the removal of tape. In regards to long term effects, continual use of tape for approximately 12 days produced a small increase in arch height when compared to a control. We did not observe a change in muscle activation or motion patterns, nor did continual use of the technique influence its initial neurophysiological or biomechanical effects (i.e. reduction in muscle activity, reduction in foot mobility, altered lower limb motion). The studies from this thesis provide evidence that anti-pronation tape should be considered in the management of individuals where reduced midfoot mobility, control of ankle motion or reduced activation of the leg muscles is desired, regardless of symptomatic status. When applied for approximately 12 days, anti-pronation tape produced a small increase in arch height ratio, but no alteration in neuromotor control. We are not aware of any definitive data on what constitutes a clinically meaningful increase in arch height, but results from a published case series suggests that our findings of a small increase in arch height may be clinically relevant for the treatment of lower extremity overuse injuries. Continual use of tape for a clinically relevant period does not alter its initial effects on foot posture and mobility or neuromotor control during gait. It would appear that the initial effects of anti-pronation tape are robust even after continuous use over a period of 11 days.

Anti-Sectarian Adult Education in Northern Ireland

Smala, Simone — 2009-06-18T00:00:00Z

This thesis presents an analysis of adult education programs concerned with reconciliation, and more specifically with reconciliation pedagogy used by community organisations in Northern Ireland. Northern Ireland for many years was the site of inter-ethnic violence expressed through sectarian and paramilitary presence, but has moved towards a more peaceful, civil society in recent years. This thesis investigates how the role of the citizen-subject in the new Northern Ireland is constituted in adult education programs and how funding regimes govern such community relations initiatives. The thesis offers a critical analysis of interviews with tutors, participants, designers and managers involved in a selected peace and reconciliation course. A broader view on reconciliation pedagogy and curriculum in anti-sectarian adult education in Northern Ireland leads to a closer exploration of social practices and power relations surrounding the chosen course, while drawing upon selected aspects of social theory, Foucauldian discourse analysis and concepts of governmentality. The analysis revealed that the chosen anti-sectarian course, ‘Us and Them’ (Workers Educational Association), proposes individualisation and responsibilisation as alternatives to community identities and nationalistic myths of origins. Equal rights are interpreted as equal rights to cultural expressions, and culture is continuously privileged over other structural differentials in Northern Ireland such as poverty, class or colour. ‘Us and Them’ is one component of a large machinery of projects designed to address the conflict situation in Northern Ireland. This machinery finds its centre in the Northern Ireland Community Relations Council, which privileges certain knowledges based on cultural consociationalism over others and which distributes funds for peace and reconciliation projects accordingly. Furthermore,the thesis examines how contemporary policy papers addressing community relations shape discourses found in anti-sectarian strategies and the rationales, strategies and policies informing “Us and Them’. The aim of the analysis is to explore the power and potential (and the limitations) of individualisation and responsibilisation as techniques in peace and reconciliation pedagogy in post-settlement ethnic conflict situations.

Anxiety in the Foreign Language Classroom: An empirical study of foreign language anxiety experienced by a group of Australian university students studying spoken Chinese

Liu, Shu-Fong Shirley — 2008-11-21T00:00:00Z

Foreign Language Anxiety is a complex phenomenon that has been found to be a predictor of foreign language achievement. Many researchers have studied the proposed notion of language anxiety in the second language classroom. MacIntyre (1995) maintained that language anxiety can play a significant role in creating individual differences in both language learning and communication. In Youngs Interviews (1992), Krashen, Young, Omaggio Hadley, Terrell, and Rardin acknowledged that speaking in the foreign language probably produces the greatest amount of anxiety in language learners. Horwitz et al. (1983) developed the FLCAS (Foreign Language Classroom Anxiety Scale) from their research and empirical studies in order to capture the specific anxiety reaction of a learner to a foreign language learning setting. The main purpose of this study was to test Horwitz et al.s construct of foreign language anxiety by validating an adapted FLCAS for students of Chinese. Most published research has focused on anxiety in learning Western languages, such as Spanish, French, and German. It was hoped that the results of this empirical study using a non-Western language would shed new light on the concept of foreign language anxiety and would expand its scope and implications. This study investigates and examines students perspective on speaking in the Spoken Chinese classes at different levels (Beginner, Intermediate, and Advanced classes) over two consecutive semesters during 2004 at The University of Queensland. Objectives of the study include: (1) investigate and compare the perception of first and second semester students foreign language anxiety in Spoken Chinese classes at Beginner, Intermediate and Advanced levels; (2) assess the reliability of the FLCAS when it is applied to a non-Western language; (3) compare the contributions of the different factors associated with Foreign Language Anxiety; (4) correlate the results obtained from foreign language anxiety and students performance; (5) investigate the role of anxiety contributing to student attrition in foreign language courses at university; and (6) identify the educational implications of the findings with the aim of creating a less stressful language classroom environment. More generally, the results of this empirical study of second language anxiety in learning Chinese should further elucidate the concept of foreign language anxiety established in studies of Western languages and expand the scope and implications of these concepts.

Anxiolytic properties of plant-derived odours in laboratory animals

Haddadan, Giti — 2012-10-22T00:00:00Z

Anxious futures : valuing young people and youth-specific performance in Australia's cultural field in the 1990's

Hunter, Mary Ann — 2008-11-21T00:00:00Z

This thesis investigates the representation, positioning, and valuing of young people and youth-specific performance in the field of cultural production in Australia in the 1990s. Using specific case-studies, this thesis argues that young people and youth-specific performance are being represented, positioned, and valued in a variety of contradictory ways as a result of a number of significant contemporary factors: namely, a prevalence of 'new generation' discourse and an attendant generationalism, a growing critical recognition of young people's 'grounded aesthetics', and existing anxieties surrounding the economic future of Australia's arts industry. This is an unstable situation for youth-specific performance, contrasting from earlier periods in Australia's theatre history when young people were positioned principally in terms of their need for 'development' (education and training) or their potential contribution to ongoing 'progression'. This thesis considers this contemporary situation in relation to issues of access and power for young people in the changed social and cultural conditions of the 1990s. The introductory chapter provides a critical background to the main issues presented in the thesis: the concepts of 'youth' and 'culture', the social and cultural characteristics of young people's lives in the 1990s, the rise of generationalist discourse, and the anxious state of the Australian arts industry. The 'institutional' site of state theatre is then taken as a beginning case study to examine the positioning of young people and youth-specific programs in 'official' cultural environments. It argues that anxious plans for the future survival of state 'flagship' companies are positioning young people and youth-specific programs in predominantly generationalist ways, using 'new generation' discourse to mask often conservative approaches. Chapter One begins with a history of Magpie Theatre (a former youth-specific company attached to the State Theatre Company of South Australia) which reflects some of the major priorities of youth-specific theatre of the last twenty years. By way of contrast, the Sydney Theatre Company's recent attempts to reposition young people and youth-specific work in the 1990s are discussed in Chapter Two. This chapter shows how the company's developmental aims and processing of new work are achieved in 'new generation' programs that strictly control young people's contribution to the company's future. Both chapters help to demonstrate the main conceptual shift in youth-specific theatre in the 1990s from 'developmentalism' to 'difference' (with reference to the concomitant growth of drama-in-education in schools), while at the same time alluding to its varying effect. Chapter Three argues that festivals, as volatile sites of cultural production, magnify the wider cultural field's 'stake of struggles': particularly, the struggles to equitably value young people's diverse contributions to developments in the cultural field, both as cultural 'innovators' and cultural 'preservers'. Centred on an interrelated critique of access, this chapter discusses the various motives and priorities of three recent youth-specific arts festivals in terms of their representation and valuing of young people and their work: the Take Over 97 National Festival for Young People, the Stage X Event, and the Loud National Media Festival of Youth Culture and the Arts. Chapter Four considers a site primarily and explicitly concerned with issues of access, representation, and value. This chapter examines in detail the 'self-narratives' of two youth-specific community-based performances, whereby young people's access to 'grounded' modes of cultural expression resulted in innovative cultural performance and signalled a regenerated social politics of community theatre. The chapter examines how Skate Girl Space by the Hereford Sisters and Zen Che by the Ningi Connection utilised young people's 'grounded aesthetics' of video performance to address young people's necessary negotiation with risk and individualisation in the late 1990s. Both projects counteracted public generationalist discourses, and challenged and reinscribed the conventions of gender performance and 'youth'. The final chapter considers the positioning of young people and youth-specific arts in Australian cultural policy, arguing that youth-specific cultural production rarely fits into the characteristic modes of arts production valorised by statistical frameworks for arts industry evaluation. The chapter calls for more open approaches whereby practice might inform policy which recognises the interconnected social, cultural and economic regimes of value that youth-specific work engages in. This thesis draws from theatre and performance studies, sociology, youth studies, cultural studies, and cultural policy studies.

Anyone for rice? : Australian food culture, multiculturalism and Asian-Australian identities

Widarsito, Sinta Jean — 2008-11-21T00:00:00Z

A participatory design approach in the engineering of ubiquitous computing systems

Timothy Cederman-Haysom — 2009-11-06T00:00:00Z

Ubiquitous computing aims to make human-computer interaction as naturalistic and functionally invisible as possible through embedding computing potential within a particular context to support human activity. However, much of ubiquitous computing research is focussed on technical innovation due to the challenges involved with deploying embedded computing, thereby reducing the commitment to the philosophical ideals of ubiquitous computing in research. This dissertation describes the investigation of a participatory approach to technically-complex research in order to understand how our view of the engineering and human challenges changes when the two are approached hand-in-hand. The domain chosen for this system was a dental surgery. Dentistry involves a complex workspace with computer interaction constrained by surgery hygiene. Ubiquitous computing offers a compelling interaction alternative to the keyboard and mouse paradigm in such an environment. A multi-method approach that employed ethnographic research and design prototyping was undertaken with dentists from several different private practices. A series of field studies used ethnographic methods such as observation and interview. Design events explored prototypes with activities such as design games, contextual interviews, role-playing and contextual prototyping. Activities were devised with the aim of providing a level playing field, whereby both designers and participants feel they can contribute equally, with their respective disciplinary knowledge. It was found that methods needed to be carefully chosen, devised and managed, in order to communicate complex concepts with participants and to constrain the design to technically feasible options. The thesis examines the design problem from the perspectives of a variety of different stakeholders within a participatory design framework, reflected upon by means of human-centred action research. Data was gathered through design speculations and observation, and explored using methods such as the Video Card Game and Video Interaction Analysis. Fieldwork was analysed using a multi-stage qualitative analysis process which informed further design collaboration with participants. The analysis of data gathered during design studies with dentists also contributed to the development of a prototype system to validate methodological contributions. The resulting prototype utilised off-the-shelf hardware and software which allowed for innovative customisation and development. In-situ prototyping (defined by the author as “participatory bootstrapping”) and a comprehensive knowledge of the domain afforded the creative application of technology. In addition to contributing to the prototype design, the interpretive understandings drawn from analysis identified how technical ideas were presented and utilised by participants of the studies, and how best to engage busy professionals. The final outcomes of the research were a multimodal ubiquitous computing system for interacting within a dental surgery; the development and implementation of a variety of methods aimed at communicating technical concepts and eliciting user motivations, practices and concerns; and a set of design principles for engineers engaging in design of systems for human use. The research presented within this thesis is primarily part of the field of human-computer interaction, but provides evidence of how engineering development can be influenced by a user-centred participatory approach. The benefits that derive from inclusive methods of design are demonstrated by the evaluation of a prototype that employed such methods. The contribution of this thesis is to demonstrate and delineate methods for developing ubiquitous computing technologies for the context of human use. This led to a set of design principles for the engineering of systems for human use: 1. Technology needs to be robust and simple to appropriate. This allows users to give insights on technology developments and also to allow users to discover for themselves how they would use the technology. 2. An evolving and carefully considered set of methods are needed to elicit communication between practitioners and across disciplines. The gaps in understandings and the different representations that arise across the disciplines provide essential clues to next steps in design. These gaps and differences form tensions that can be exploited productively. 3. Context is important for determining which design steps to take. Rather than abstracting a problem in order to solve it, as is usual in engineering design, the problem should remain grounded in the context of use. It reveals what the real problems are that need to be solved rather than the imagined ones. This requires an appreciation of the situated nature of action and of the variability of work. In turn it also requires an appreciation of what the human can and does do and what the machine should support. 4. Accountability in design is required. There is a fundamental tension between trying to make something work and seeing what really does work; specifically it is necessary to understand when automation is worth it in human machine systems. While engaged in the design process, engineers should ask how much technology should reconfigure human practices because of a useful outcome, rather than attempting to automate and converge devices for its own sake. A clear understanding of the constraints and workings of the work space needs to be balanced with the understandings of the limitations of the technology in order to design a system that improves work practice and empowers the practitioner.

A perception-influence model of innovation implementation in project - based engineering

Miller, Andrew — 2009-11-24T00:00:00Z

Innovation is an imperative in all industry sectors. For those such as construction, which are not considered high-tech and which operate as one-off projects, the uptake and diffusion of new innovations into ongoing practice across projects pose particular problems. The nature of these problems faced at a project level needs to be better understood. This thesis is an exploration of innovation implementation in the context of Project-Based Engineering (PBE). It is an empirical investigation of how new planning technologies are implemented in major infrastructure construction projects and the barriers that prevent such implementations from being effective. The findings of this investigation are used to develop and evaluate a new model of innovation implementation in this context. The research design is centred on the immersion of a participant-observer in seven live construction projects over a period of 3.5 years. Each project studied was implementing the same innovation: 4D CAD modelling (3D design model + the construction schedule). A wide cross-section of data was gathered in the field including direct observations, documents and other work products from participation, email and other correspondence associated with the 4D CAD implementations, and formal and informal discussions with project-participants. These data were analysed using content analysis software to find patterns. The research was iterative and involved three phases. The initial phase was a pilot study of implementation in practice using the data from one project. It produced rich descriptions of what transpired and a critical comparison with accounts from the literature. This led to a series of propositions about the influence of project-participant perceptions that were synthesised into a new theoretical model: the initial Perception-Influence model (P-I1 model). The middle research phase then developed this model iteratively using a more-focused data collection and content analysis across four construction project organisations. This was done to provide supporting evidence for the theoretical constructs in the P-I1 model as well as to refine them and add new ones. The outcomes of the middle phase were the P-I2 and P-I3 models. The final research phase analysed the data from the last two project organisations in terms of the P-I model framework with a view to evaluating the model’s theoretical significance and practical applications. The P-I model shows that negative perceptions of value, benefit and usability can cause an innovation implementation to be ineffective as a result of discontinued use or neglect. It provides a map for the progression of an implementation using the perceptions and actions of project-participants as primary constructs. The model proposes that each perception is formed by a number of contributing factors or secondary constructs synthesised from implementation research and user acceptance literature, for example, an opinion or concern about how much an innovation costs (i.e. transaction costs). It also proposes that each perception has both a positive and negative associated action. The constructs that make up the P-I model are grounded in the empirical data. This is because the actions, opinions and concerns of project-participants observed in live projects are evident in project documentation such as emails. These two sources (i.e. observations and project documentation) provide data sets that were used to triangulate inferences about the perceptions of project-participants and the outcome of each 4D CAD implementation (i.e. effective or otherwise). This aspect of the research was not only important for the recommendation of potential applications for the P-I model but also during its conception, development and evaluation. The P-I model is a new and important perspective for both implementation research and PBE practitioners. It helps satisfy the calls for studies of innovation implementation that focus on factors at an individual level and those asking for a better understanding of innovative behaviour. This work shows PBE practitioners how the perceptions of project-participants can have a major impact on the effectiveness of an innovation implementation. The findings provide an evidential basis that can improve implementation effectiveness, especially in PBE organisations. The knowledge built into the P-I model can also assist the planning and execution of innovation implementation strategies, aid in the assessment and redirection of those in progress, and help document lessons learned for implementations within project organisations that have been previously completed. This research uses the P-I model to open the way for future empirical studies of innovation implementation in PBE contexts beyond construction. These would also provide data to further refine the constructs in the model.

A philosophical investigation of entertainment

Fletcher, Clifton — 2012-09-20T00:00:00Z

A PHYSIOLOGIC INVESTIGATION OF SPEECH MOTOR DEVELOPMENT

Cheng, Hei Yan — 2008-11-21T00:00:00Z

To date, very little is known about the physiologic development of speech production. Information pertaining to tongue movements during speech in children and adolescents is particularly scarce. An improved understanding of the fundamental motor processes for speech will remarkably strengthen our ability to differentially diagnose and treat a number of speech and language disorders in chldren and adolescents. Using advanced instrumental techniques, this thesis aimed to comprehensively examine the developmental process of tongue movement during speech production over the age span of 6 years to adulthood. A total of 48 speakers participated in the current investigations, with six males and six females in each of the following age groups: (i) aged 6- to 7-years; (ii) 8- to 11- years; (iii) 12- to 17-years; and (iv) adults. All participants were native speakers of Australian English and achieved within age appropriate ranges on a battery of speech and oral motor tests. Two physiological assessments, electropalatography (EPG) and electromagnetic articulography (EMA), were conducted to determine the spatial and temporal characteristics and stability of tongue-tip and tongue-body speech movements in developing speech motor systems. EPG recorded details of the tongue motion and contact at the hard palate during production of lingual consonants. With age, there was a reduction of tongue-to-palate contact and an anterior shfi in the place of articulation for alveolar and post-alveolar sounds. Maturation of the velar consonant, in contrast, was primarily marked by greater stability of tongue-to-palate contact. In the timing domain, duration of the consonant closure phase (i.e., when the tongue is in direct contact with the palate) reduced with age, although no changes in duration variability was seen. A concurrent trend of declining duration and duration variability over entire sentences was also identified. Development of tongue-tip - tongue-body coordination was inferred fiom EPG examination of the transition of velar - alveolar articulatory gestures (i.e., during production of the /kl/ consonant cluster). With advanced motor control, older speakers demonstrated more coherently organized gestures within a phonetic sequence and increased differentiation of tongue-tip - tongue-body movement, resulting in phonetic segments that were more distinct and precisely timed. As EPG assessment focused primarily on tongue-to-palate contacts in speech production, EMA was used to identify changes in tongue motion (i.e., movement distance, duration, speed, acceleration and deceleration) in the closing and opening segments of lingual consonant production. In general, it was found that closing and opening durations decreased across the age spans studied; however, changes in movement distance, speed, acceleration and deceleration were less consistently observed. In contrast, the token-to-token variation for each parameter declined as a function of age. Additionally, adults continued to exhibit more stable spatiotemporal patterning of their tongue movements during sentence production compared to both children and adolescents. Lastly, given that the tongue and jaw appear to be closely related in speech motor development, EMA was used to examine the kinematic coordination of the two articulators during consonant production. Interestingly, development of tongue-tip and jaw coordination for speech was manifested in more tightly synchronized movements. In contrast, with maturity, tongue-body and jaw retained movement independence but developed a more consistent kinematic relationship from trial-to-trial. The present EPG and EMA findings suggested that continual, though nonlinear and nonuniform, changes are occurring in the speech motor system from 6 years, to adolescence, and into adulthood.

A Pluralistic Analysis of Housing Renovation Choices in Brisbane

Ti Ching Peng — 2009-11-19T00:00:00Z

Housing renovation is a major activity for many consumers in Australia, and its growing popularity in recent years has been reflected not only by it share in GDP but also by publicity it receives via home exhibitions and numerous TV renovation shows. Despite this, and despite similar experiences in other countries, research on how decisions in this sector are made is still quite sparse, a major restraint being the limitation of secondary data. This thesis attempts to improve knowledge in this area while at the same time exploring the feasibility and benefits of doing applied economic research in a pluralistic manner. From the perspective of mainstream economics, individuals’ decision-making in the context of renovation can be modelled in terms of utility/profit maximization subject to a budget constraint. The literature that has attempted to follow this research strategy is reviewed in Chapter 2, as is research undertaken in sociology that has been partly informed by behavioural economics. The economic literature fails to recognize the possible importance of social influence and psychological factors in this context. This could be unfortunate, as these factors, which are seen as important in some other economic paradigms, may explain how some renovators get derailed from rational decision-making. The methodology of pluralism offers a way to bridge between these divergent arguments by keeping mainstream insights in mind whilst at the same time adopting an ‘open-minded’ rather than ‘autistic’ attitudes towards different paradigms and embracing ‘realistic’ aspects (e.g. limits to individuals’ rational behaviours) rather than assuming them away. Chapter 3 examines the case for pluralism and shows that although debate in economics is often couched in terms of a battle between fundamentally opposed ‘mainstream’ and ‘heterodox’ views, a deeper analysis of sub-paradigms reveals a complex web of partially overlapping core ideas. Once this richer view of schools of thought in economics is recognized, orthodox economics and heterodox economics are not necessarily incompatible but rather seem potentially complementary. Despite renovation being a popular topic in Australia, relevant micro-data regarding individuals’ choices and their social and psychological attitudes towards renovation are in short supply. Therefore, unlike most previous renovation studies using published secondary data, this study involved the collection of primary data by a survey mailed to a sample of Brisbane residents in late 2006 and early 2007. Chapter 4 explains this choice of method, which provided data on respondents’ decision-making regarding renovation, their demographics, and social and psychological factors. This data set was used to analyse the following four topics: individuals’ decision to renovate or not (Chapter 5); renovators’ choice between using their own labour (DIY) or outsourcing the work (Chapter 6); psychographic segments of ‘non-renovators’, ‘DIY-renovators’ and ‘Hire-renovators’ (renovators who outsource the work) (Chapter 7); and factors shaping renovators’ tendencies to engage in overcapitalization and cost escalation in their renovation projects (Chapter 8). The pluralistic philosophy is applied in an addition way to analyse these issues, since the study used a variety of statistical techniques. The empirical results reveal that this dual form of pluralism—involving theoretical inputs from a variety of paradigms (including both ‘old’ and ‘new’ behavioural economics, socio-economics and others) and a variety of analytical techniques (cluster analysis, logistic regression and others)—does indeed widen our understanding of this topic. Generally speaking, the empirical finding stresses the importance of psychological factors in the context of individuals’ decision-making on renovation. In analysing individuals’ decisions to renovate or not, it is shown that, besides conventional factors (such as age of respondents), the psychological factor ‘perceived self-performance in renovation’ is crucial: individuals are more likely to embrace renovation if they perceive highly their ability to handle the renovation process. In exploring renovators’ decisions to engage in do-it-yourself (DIY) or hire others to do the work in their latest renovation projects, besides factors such as the scope of the project and renovators’ capabilities, the psychological factor ‘trust in contractors’ plays an important role: renovators are more likely to choose to use their own labour if they are uncertain about contractors’ reliability while those who outsource renovation works are in general more trusting than those who engage in DIY. The exploratory psychographic analysis of heterogeneous groups within each of the three groups (non-renovators, DIY-renovators and Hire-renovators) indicates the necessity of recognizing the heterogeneity the population when designing policies to improve the efficiency of the renovation market. In the investigation of renovators’ mistakes that lead to overcapitalization and cost escalation, psychological factors did not show their expected strong influences on either of these phenomena. However, it was found that the factors related to the project itself, especially the scope of the project (approximated by ‘time spent on preparation’) and the age of house, influence renovators’ overcapitalized spending and the extent of their cost escalation.

APPLICATION AND APPRAISAL OF A MULTI-OBJECTIVE DECISION SUPPORT SYSTEM FOR THE EVALUATION OF FARM FORESTRY VIABILITY

David Ian Jeffreys — 2009-12-03T00:00:00Z

Abstract This thesis presents innovative applications of Multi-Objective Decision Support Systems (MODSS) to forestry decision support. New MODSS methodologies were developed to assess and evaluate forestry practices and finance regimes. The assessment of forestry investments draw on case studies conducted in the Hodgson Creek catchment on the Darling Downs in south Queensland and on the Atherton Tablelands in north Queensland, Australia. MODSS are systems that aid decision-making, in which a set of alternative management options are evaluated against a set of decision criteria. The criteria, that represent the stakeholders’ goals and objectives, are weighted to reflect stakeholder preferences regarding their relative importance. The weighted criteria scores are then aggregated to create an overall measure of option performance. In the first case study, MODSS procedures identified from the literature as being most suitable to forestry and the MODSS software package DEFINITE was used. After a critical review of the first study, a new MODSS was developed to address the particular needs of forestry evaluations and the weaknesses of current MODSS for addressing these needs. Limitations of the Hodgson Creek MODSS included lack of stakeholder engagement in the MODSS development process, inefficient use of the stakeholder time and an excessive work load on the experts in the scoring process. The new MODSS development process included the combined use of weighted sum and Electré aggregation methods, these being compensatory and non-compensatory aggregation methods. This combination of aggregation methods provided a measure of overall option performance and identified the presence of fatal flaws in the options. Various criteria weighting methods were trialled – including rank order methods, the analytical hierarchy process and direct assessments – to assess their utility for defining weights that reflected stakeholder priorities. A new hybrid weighting technique was developed using a combination of rank order methods and direct assessments. A new and innovative process for scoring options and criteria was developed, using an adaption of the Nominal Group Technique (NGT) in conjunction with a new computer-based Group Decision Support System (GDSS). This iterative process involved repeated rounds of individual scoring and group discussions. In the workshop conducted to elicit scores from experts, the GDSS was used to identify criteria where the elicited scores differed and discussions were focused on these criteria. After the discussions the options were rescored against the criteria and discussed further. This analysis was innovative in that uncertainty around the individual option scores was addressed for the first time using MODSS. This new application was developed in a spreadsheet using the risk analysis package @RISK. Evaluations of forestry options were undertaken at various time scales to address the long delay between incurring costs of tree planting and receiving returns from harvest. The various time scales identify the periods in which environmental and social benefits occurred as the trees grow and the economic benefits occurred at clearfell (or selective) harvest. This thesis specifically focuses on situations where measured and modelled data is not available, and seeks to increase the scientific rigour of the use of expert and stakeholder opinion in MODSS. The MODSS analyses revealed that forestry in the case study areas had the potential to offer considerable economic, environmental and social benefits to both landholders and the wider community. However, these benefits (and the associated costs) were not viewed as equally important. The MODSS developed in this study addressed these concerns. The benefits and costs of an option were reflected in its performance against the criteria. The degree of importance of the individual criteria varied from minor to high and overriding all other considerations. Criteria against which an option performed highly (the option’s strengths) were identified, as were criteria against which an option performed poorly (the option’s weaknesses). When these weaknesses occurred in highly important criteria, these were identified as fatal flaws in the option. The first case study in the Hodgson Creek catchment considered eight forestry options against 17 economic criteria, 12 environmental criteria and 12 social criteria. The second case study on the Atherton Tablelands considered 16 forestry options against eight economic criteria, six environmental criteria and five social criteria. The MODSS analysis identified the most preferred forestry options and the strengths and weaknesses of the options. In both case studies the most preferred options were large or medium-sized plantations with monoculture plantings with an element of non-landholder funding, in the form of government funding, joint ventures or land leasing agreements. These options had the highest performance against the economic criteria at all time scales and satisfactory environmental and social performance. Other forestry options that performed well included plantings focused on under-utilised land areas and salinity prevention areas, agroforestry, and selective harvesting of private native forest. These options generally had a higher level of performance against the social and environmental criteria, but lower levels of performance against economic criteria. These plantings would be undertaken for environmental and social reasons and not for financial returns. The application of MODSS developed in this thesis presents a significant scientific contribution to MODSS methodology. This thesis includes: the use of multiple time-periods to address the temporal differences in the delivery of benefits and costs, the use of NGT and a GDSS to provide a process for rapidly eliciting expert opinion, and the use of the combination of Electré and weighted sum aggregation methods to provide an overall measure of option performance and to identify fatal flaws in the options.

Application of a bioinformatic/biochemical hybrid approach to determine the structure of protein complexes and multi domain proteins.

Dmitri Mouradov — 2009-05-15T00:00:00Z

A recent shift towards proteomics has seen many structural genomics initiatives set up for high-throughput structure determination using traditional methods of x-ray crystallography and NMR. The next step in the proteomic revolution focuses on the interplay of multi-protein complexes and transient protein-protein interactions, which are involved in many cellular functions. Greater understanding of protein-protein interactions will inevitably lead to better comprehension of the regulation of cellular process, which has implications in biomedical sciences and biotechnology. Even though many high-resolution initiatives focus on proteins and protein complexes, their structure-determination success rates are still low. An emerging approach uses chemical cross-linking and mass spectrometry to derive a set of sparse distance constrains, which can be used for building models of proteins and to map out residues in protein interaction interface based on partial structural information. This technique allows low-resolution identification of protein structures and their interactions in cases where traditional structure determination techniques did not produce results. Chemical cross-linkers have been successfully used for many years in identifying interacting proteins. However, recent advances in mass spectrometry have allowed the identification of exact insertion points of low-abundance cross-links and hence has opened up a new perspective on the use of cross-linkers in combination with computational structure prediction. For protein interaction studies, the approach uses chemical cross-linking information with molecular docking, so that the cross-links are treated as explicit constraints in the calculations. This study focuses on a low-cost and rapid approach to structure prediction, where partial structural information and distance constraints can be used to obtain the relative orientation of interacting proteins and domains, specifically as a rescue strategy where traditional high resolution structure determination methods were unsuccessful. This hybrid biochemical/bioinformatics approach was applied in the determination of structure of the latexin:carboxypeptidase A complex, and succeeded in achieving 4 Å rmsd compared to the crystal structure determined subsequently (Mouradov et al., 2006). Application of the bioinformatics/biochemical approach to multi-domain proteins was carried out on murine acyl-CoA thioesterase 7 (Acot7). X-ray crystallography provided structures of the two separate domains of Acot7, however the full length protein did not crystalise. Combining chemical cross-linking, mass spectrometry, molecular docking and homology modeling we were able to reconstruct how the two domains are arranged in the full length protein (Forwood et al., 2007). Limitations of this technique caused by the enormous complexity of the cross-linking reaction mixtures were identified and emphasized by analysing a large (four protein) complex of DNA polymerase III, where only one inter-protein cross-link was identified. A rapid and cost-effective method for identification of cross-linked peptides using a commercially available cross-linker was developed as part of the overall aim of streamlining the hybrid biochemical/bioinformatics in order for it to become a generally applicable technique for rapid protein structure characterisation (King et al., 2008). Finally an in-house software package was developed for assignment of cross-linked peptides based on m/z values.

Application of dielectrophoresis to mineral processing

Ballantyne, Grant Randal — 2012-09-14T00:00:00Z

Application of laminar jet break-up to the preparation of monodisperse poly(ester) microparticles

Rahman, Mohammad Mizanur — 2008-11-21T00:00:00Z

Poly(ester) drug-loaded microspheres are most commonly prepared by emulsion solvent evaporation/extraction in which the polymer is dissolved in an organic solvent which is dispersed in an aqueous continuous phase. Typically, the o/w or more complex w/o/w (required for encapsulation of hydrophilic actives) emulsions are produced by homogenization, sonication or high speed stirring which yield microspheres with wide size distributions. Standard deviations of 25-50% of the mean diameter are not uncommon for microspheres prepared by such technologies. This lack of control and predictability are limitations of the current technologies. Particle size is a primary determinant of drug release and particle deposition following in vivo administration. Any variation in the size of particles will lead to sub-optimal delivery in which release kinetics are difficult to control. A long-sought after goal in particulate drug delivery technologies has therefore been to precisely control the size of the particles. Many theoretical and experimental studies have shown that uniformly sized liquid-liquid dispersions can be formed by laminar jet break-up. However, to date nobody has used the resulting dispersions for the preparation of drug loaded polymeric microparticles. The aim of this project was therefore to investigate the application of laminar jet break-up for the preparation of o/w dispersions for the fabrication of monodisperse biodegradable microparticles of controlled and predictable size. In this study, poly(@-caprolactone) was used as the polymer and was dissolved in an organic solvent (initially and mainly, dichloromethane). The organic polymer solution was loaded into a high precision syringe pump and pumped through orifices of different diameters into an aqueous phase containing poly(vinyl alcohol) as surfactant. The dispersions were subsequently stirred to facilitate solvent removal leading to polymer precipitation and microparticle formation. Resulting microparticles were characterized by optical microscopy and low angle laser light scattering. In the first series of investigations (Chapter 2), the effect of orifice diameter, flow rate (particularly within the laminar jet region), type of organic solvent and polymer/surfactant concentrations on the size and polydispersity of the microparticles were investigated. Uniformly sized microspheres (polydispersity index < 0.5) were observed to form in both the dripping and laminar jet flow regions. Microspheres formed in the laminar region were however smaller and there was a trend of decreasing particle size and polydispersity upon approaching the flow velocity resulting in maximum jet-length. In the dewaving region, polydispersity of the particles was found to increase. Consequently, all further studies were undertaken in the laminar jet region using the flow rate yielding maximum jet length. Polydispersity as well as size of micrparticles was influenced by concentration of poly(vinylalcohol) in the continuous aqueous phase (used as viscosity modifier and surfactant). A concentration of 0.91 % w/v poly(vinylalcohol) was found most suitable with higher/lower concentrations resulting in increased polydispersity as a result of viscosity and interfacial effects. Size and polydispersity of microspheres was found to be also influenced by the organic solvent used to dissolve the poly(ester) with dichloromethane yielding the smallest and most uniformly dispersed microspheres. Size of microspheres produced from dispersions prepared by laminar jet break-up not surprisingly increased with both the size of the orifice used for jetting and the concentration of polymer. In chapter 3, a factorial designed study combined with mathematical modelling was used to investigate whether a relationship existed between the response variable of particle size and these two independent process variables (nozzle orifice diameter and polymer concentration) for microspheres prepared under conditions based on the results of chapter 2 (namely jetting at a velocity yielding maximum jet length, using dichloromethane as the organic solvent and using a poly(vinylalcohol) concentration of 0.91 % w/v in the aqueous phase). Based on the results of four trials (22 factorial design), a linear, algebraic first-degree polynomial correlation was predicted to describe the effects of nozzle orifice diameter, polymer concentration and their interaction on the mean particle size of microspheres. The model was validated by 11 experimental results within the factor space. It was found that the predicted values of ten experiments (means, n=3) were within ±5.5% of the calculated values. Only one experimental result deviated by greater than 10% from that predicted. The model thus allows a prescribed size of particles to be prepared by selecting the appropriate nozzle orifice size and polymer concentration.

Application of Luminescent Diamond Nanocrystals to Intra-Cellular Optical Imaging

Bradley R Smith — 2010-10-04T00:00:00Z

Nanodiamond is capable of filling a niche in the demand for new optical labelling technologies. This is due to the potential to encapsulate photo-stable luminescent nitrogen-vacancy defects into diamond crystals which are biologically compatible and have dimensions smaller than 10 nanometres. The focus of this thesis is the development of diamond as a near-ideal optical label for intracellular imaging. Facets of this work include producing, enhancing and detecting luminescence in single-digit nanodiamonds and interfacing this material with an intracellular environment. In this thesis the first observation of nitrogen-vacancy luminescence in weakly bound clusters of 5-nm diamond is described. These luminescent defect centres are produced in crystals with a diameter of only 29 carbon atoms. Interesting properties are then characterised, such as the scaling of luminescence intensity with crystal size and the distribution of nitrogen in single-digit nanodiamonds. Enhancement of this luminescence is found to be possible by surface oxidation treatment which removes intrinsic amorphous carbon shells. These shells surround sub-10 nm diamonds and as our results show, quench nitrogen-vacancy luminescence. By applying this technique, previously observed background luminescence is also ameliorated. A technique for background–free luminescence detection is demonstrated, despite the low absorption cross-section of nitrogen-vacancy centres. This is achieved by exploiting the long excited-state lifetime of luminescent nanodiamonds with time-gated detection. The high frame-rate desired for particle tracking in cells is maintained by implementing a novel wide-field arrangement. Finally, the first demonstration of nanodiamond as a scattering optical label in a biological environment is presented, showing that nanodiamonds can be biologically compatible and well contrasted from the cell background. Together these results represent a step towards resolving extended intracellular biological processes, which require sub-10 nm, photostable optical labelling. For other applications such as high-resolution magnetometry and near-field optical microscopy, the discovery of luminescence in 5-nm crystals and the reduction of short-lived luminescence presented in this work is a critical step forward.

Application of Metal Foams for Improving the Performance of Air-Cooled Heat Exchangers

Mostafa Odabaee — 2011-07-20T00:00:00Z

This thesis investigates the application of metal foam heat exchangers to the air-cooled condensers of geothermal power plants in Australia where the resources are mostly located at the arid areas where there is no water for evaporative cooling of the power plant. One way to remove the heat from the thermodynamic cycles is to use (the most common) finned-tube heat exchangers, consisting of tubes with external fins to increase the air-side heat exchange surface. Another possible alternative is a class of designed porous materials called metal foams, containing such advantages as low-density, high area/volume ratio, and high strength structure. Therefore, they have been applied in a variety of industrial. The numerical study, in three main sections, has been conducted to explore that possibility. First, a comparison between the performance of a metal foam-wrapped solid cylinder in cross-flow and a commercially available finned-tune heat exchanger is investigated. Effects of the key parameters including the free-stream velocity and characteristics of metal foam such as porosity, permeability, and form drag coefficient on heat and fluid flow are examined. Being a determining factor in pressure drop and heat transfer increment, the porous layer thickness is changed systematically to observe that there is an optimum layer thickness beyond which the heat transfer does not improve while the pressure drop continues to increase. This has been verified by the application of Bejan’s Intersection of Asymptotes method. Results have been compared to those of a finned-tube heat exchanger to observe a higher area goodness factor for metal foam-wrapped cylinder. In the second part, an optimization study is carried out to discover an optimized design of metal foam heat exchangers as replacements for finned-tubes in air-cooled condensers of a geothermal power plant. Two different optimization techniques, based on first and second law (of thermodynamics) are reported. While the former leads to the highest heat transfer rate with as low pressure drop as possible, the latter minimizes the generated entropy in the thermodynamic system. Interestingly the two methods lead to the same optimal design. The new design has been compared to the conventional air-cooled condenser designed and optimized by using the commercially available software ASPEN. It is shown that while the heat transfer rate increases significantly (by an order of magnitude) compared to the finned tube for the same main flow obstruction height, the pressure drop increase is within an acceptable range. Further comparison between the two systems are carried out, making use of Mahjoob and Vafai's performance factor developed specifically for metal foam heat exchangers. Following that, the third part explores the heat transfer from a metal foam-wrapped tube bundle. Effects of key parameters, including the free stream velocity, longitudinal and transversal tube pitch, metal foam thickness and characteristics of the foam on heat and fluid flow are examined. It can be observed that the performance of the metal foam heat exchangers, measured in terms of area goodness factor, can be about four times better than that of the conventional design of finned-tube heat exchangers. It is also found that even a very thin layer of metal foam, when wrapped around a bare tube bundle, can significantly improve the area goodness factor. Finally, it is shown that while friction factor is more sensitive to the metal foam permeability than its porosity, the converse is true when it comes to the Colburn factor.

Application of 129Xe NMR to the Study of the behaviour of Polymers in Supercritical Carbon Dioxide

Kylie Varcoe — 2009-10-15T00:00:00Z

Applications and implications of systematic planning for the Pantanal Wetland Biosphere Reserve - Brazil

Reinaldo Lourival — 2008-10-13T00:00:00Z

Applied Science of Professional Rugby League

Tim Gabbett — 2012-06-14T00:00:00Z

ABSTRACT The present thesis examined the applied science of professional rugby league, with a particular focus on (1) the applied physiology of rugby league, (2) skill acquisition in rugby league, and (3) injury incidence in rugby league. In theme one (the Applied Physiology of Rugby League), the specific physical demands of professional rugby league match-play, and the use of game-based training as a means of replicating these demands were investigated. Using both global positioning system (GPS) and ball-in-play analysis, it was revealed that the relative locomotor demands of professional rugby league match-play were similar between hit-up forwards, wide-running forwards, adjustables, and outside backs, although outside backs covered greater absolute distances than other playing positions. In addition, the high-speed running demands were greater in adjustables and outside backs, while the collision and repeated high-intensity effort demands were greater in hit-up forwards and wide-running forwards. The greatest distances covered, high-speed running distances, and frequency of collisions and repeated high-intensity effort bouts were up to 98% greater than the average physical demands. These findings suggest that conditioning programs that are based on the mean values of competition will likely result in players being underprepared for the most demanding passages of competition. The ‘ball-in-play’ analysis demonstrated that players were required to compete for prolonged periods of play, with short recovery periods during brief stoppages in play. Neither traditional conditioning, repeated high-intensity effort training, nor game-based training adequately replicated the physical demands of match-play, suggesting that improvements in conditioning practices may be necessary to adequately prepare players for National Rugby League competition. Differences in the physical demands between National Rugby League and National Youth Competition matches, and junior and senior small-sided games were observed, as evidenced by differences in match activity cycles and high-intensity running demands. The ball was in play longer in National Rugby League matches (~55 min) than National Youth Competition matches (~50 min), and National Rugby League matches had longer average activity cycles (81.2 ± 16.1 s vs. 72.0 ± 14.7 s), longer maximal activity cycles (318.3 ± 65.4 s vs. 288.9 ± 57.5 s), a smaller proportion of short duration (<45 s) activity cycles, and a greater proportion of longer duration (>91-600 s) activity cycles. In addition, senior players covered greater total distances, and completed greater amounts of high-speed running than junior players in small-sided games. Given the salary cap constraints in the National Rugby League competition, teams face pressures to retain older, more experienced players within their playing roster. Due to these pressures, talented, younger players are often ‘fast-tracked’ to the National Rugby League. The differences in physical demands between National Rugby League and National Youth Competition matches, and junior and senior small-sided games, suggest that physical preparation should differ between younger and older players. Perhaps more importantly, the present findings suggest that the training demands of National Youth Competition players should be increased in preparation for National Rugby League matches. In theme two (Skill Acquisition in Rugby League), dual-task techniques were used to assess the attentional demands of selected rugby league skills, as a tool to both measure and ultimately facilitate skill learning. These methods were also used to determine the relationship between off-field measures of skill and competition performances. Differences were found in the dual-task draw and pass proficiency of higher-skilled and lesser-skilled rugby league players, despite a lack of significant differences in primary task performance. These findings demonstrate the advantage of dual-task performance assessments over single-task measures in predicting the capability of different players to compete successfully at a higher level where concurrent demands are high. Based on this information, coaches may use the dual-task draw and pass assessment to provide insight into the level of practice complexity required by individual players. Dual-task training appeared to have some benefits for skill learning, resulting in better acquisition and retention of skill compared to conventional single-task training. Indeed, the mean improvement in dual-task draw and pass proficiency in a dual-task training group (10.0%) was found to be greater than that in a single-task training group (2.3%), offering a moderate effect size (d = 0.57). However, no differences were found in transfer test performance (a small-sided game which provided regular draw and pass opportunities) between players trained under single-task and dual-task conditions. While dual-task training appears to offer advantages over single-task training as a skill learning stimulus to improve time-sharing and dual-task draw and pass performance, further studies are required to confirm the transfer of this advantage to match-like situations. The dual-task draw and pass proficiency of rugby league players (assessed off-field) was related meaningfully to player performance in competition; higher dual-task performance assessed off-field was associated with more successful competition draw and pass attempts. In addition, draw and pass proficiency declined with increases in task complexity. These findings provide evidence of the greater attentional demands of more complex drawing and passing scenarios in professional rugby league. From a practical perspective, these findings also provide evidence of the practical utility of off-field dual-task testing in supplying information predictive of skills performance in competition. Expert-novice differences were found in the dual-task anticipatory skill of rugby league players in response to a “life-like” game-specific video-based test. High-skilled rugby league players had greater response accuracy and decision times than intermediate- and low-skilled players. Furthermore, secondary task performance (verbal reaction times and accuracy in response to a tone recognition task) was poorer in the low-skilled players, demonstrating the increased attentional demands that novice rugby league players experience while performing game-specific decision-making tasks. The anticipation test has several potential practical applications. Firstly, it is likely that it could be used to complement existing measures of playing ability for selecting individuals for higher level representation. Secondly, within National Rugby League high performance programs, the test may be used diagnostically to identify individuals who have a specific need for training in anticipatory skills. Finally, additional video clips of scenarios not used in the anticipation test, could be used to train anticipatory skills, and complement on-field training performed in rugby league training sessions. In theme three (Injury Incidence in Rugby League), the relationship between physical and skill qualities, training loads and injury risk were investigated. In addition, an injury prediction model to prevent non-contact, soft-tissue injuries was developed and implemented. Significant relationships were found between training load and injury with greater training loads being associated with higher injury rates. High strength and power training loads were associated with increases in field injury rates, while greater than average volumes of high-speed running increased the risk of lower-body soft-tissue injury. However, some training factors protected against lower-body soft-tissue injury, with greater amounts of aerobic activity (i.e., low-speed running) being associated with a lower risk of soft-tissue injury. In addition, players with poor repeated-sprint ability and prolonged high-intensity intermittent running ability were at greater risk of sustaining a contact injury. These findings, taken with the physical demands of professional rugby league match-play (i.e. long ball in play periods, and regular performance of repeated high-intensity effort bouts), and the protective effect that well-developed aerobic qualities have against fatigue-induced reductions in skill, demonstrate the importance of high-intensity aerobic training for performance enhancement and injury prevention in professional rugby league players. Based on the relationship between training load and injury, an injury prediction model was developed and implemented. Training load ‘thresholds’ were developed for players on an individual basis. The injury prediction model was found to have acceptable specificity (98.8%) and sensitivity (87.1%). When players exceeded the training load thresholds, they were injured 70 times more often, whereas when training loads were below the injury threshold, players were injured 1/10 as often. These findings provide information on the training dose-response relationship and a scientific method of monitoring and regulating training load in elite rugby league players. Summary The findings of the conducted experiments demonstrate that: 1. The high-speed running demands of professional rugby league match-play are greater in adjustables and outside backs, while the collision and repeated high-intensity effort demands are greater in hit-up forwards and wide-running forwards. 2. Neither traditional conditioning, repeated high-intensity effort training, nor game-based training, adequately replicate the physical demands of match-play, suggesting that improvements in conditioning practices may be necessary to properly prepare players for National Rugby League competition. 3. The physical demands of National Rugby League matches are significantly greater than National Youth Competition matches. The ball was in play longer in National Rugby League matches (~55 min) than National Youth Competition matches (~50 min), and National Rugby League matches had longer average activity cycles (81.2 s vs. 72.0 s), longer maximal activity cycles (318.3 s vs. 288.9 s), a smaller proportion of short duration (<45 s) activity cycles and a greater proportion of longer duration (>91-600 s) activity cycles. 4. Selected physical (e.g. acceleration, maximum velocity, lean body mass, lower body muscular power, and maximal aerobic power) and skill (e.g. tackling proficiency, dual-task draw and pass proficiency) qualities discriminated high-skilled and lesser-skilled rugby league players. In addition, high-skilled players were older and more experienced than lesser-skilled players. 5. Selected physical and skill qualities were related to game performance. Better repeated-sprint ability, and prolonged high-intensity running ability were associated with greater minutes played, while dual-task draw and pass proficiency was significantly associated with the number of try assists and line break assists. 6. Greater lower body muscular power, acceleration, change of direction speed, and lean body mass, along with greater age and playing experience were associated with better tackling proficiency. In addition, greater aerobic fitness was protective against fatigue-induced reductions in tackling proficiency. 7. Differences were observed between high-skilled and lesser-skilled players on a dual-task draw and pass assessment. While no differences were detected in primary task performance between groups, the performance of the high-skilled players was more resistant to skill decrement under dual-task conditions. 8. Eight weeks of dual-task training appeared to have some benefits for skill learning, resulting in better acquisition and retention of this important skill. The mean improvement in dual-task draw and pass proficiency in the dual-task training group (10.0%) was greater than the single-task training group (2.3%), although no differences were found in transfer test performance between players trained under single-task and dual-task conditions. 9. The dual-task draw and pass proficiency of rugby league players (assessed off-field) was related to competition performances; higher dual-task performance was associated with more successful competition draw and pass attempts. 10. High-skilled rugby league players had greater response accuracy and decision times than intermediate- and low-skilled players on a “life-like” game-specific video-based anticipation test. Furthermore, secondary task performance (verbal reaction times and accuracy in response to a tone recognition task) was poorer in the low-skilled players, demonstrating the increased attentional demands of performing game-specific decision-making tasks in novice rugby league players. 11. A significant relationship was found between training loads and injury; greater training loads were associated with higher injury rates. High strength and power training loads were associated with increases in field injury rates, while greater than average volumes of high-speed running increased the risk of lower-body soft-tissue injury. 12. An injury prediction model was developed and implemented to prevent non-contact, soft-tissue injuries. The injury prediction model was found to have acceptable specificity (98.8%) and sensitivity (87.1%). When players exceeded the training load thresholds, they were injured 70 times as often, whereas when training loads were below the injury threshold, players were injured 1/10 as often. These findings suggest that systematically applying sport science to rugby league offers a promising means of developing effective and evidence-based approaches to physical preparation, skill acquisition, and injury prevention.