UQ Theses Collection (RHD) - UQ staff and students only - UQ eSpace

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

Antibody mediated immunity against malaria and application of phage display technology

Vukovic, Peter — 2011-08-29T00:00:00Z

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 and quality parameters of Australian unifloral honey

Mossel, Brenda Louise. — 2007-08-24T18:01:43Z

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.

Antitrust enforcement in the software market : a study of the Microsoft cases in the United States

Chen, Yi-Jen — 2013-04-02T13:38:04Z

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 performance model for coal-washing dense medium cyclones

Wood, Christopher John — 2012-11-12T15:20:18Z

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 Piston and Die Test to Predict Laboratory-scale HPGR Performance

Hawkins, Rachel Anne — 2008-11-21T00:00:00Z

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 molecular markers to breeding barleys for disease resistance

Poulsen, David Malcolm Ernest. — 2007-08-24T00:00:00Z

Application of the tree augmented naive Bayes network to classification and forecasting

Tang, Adelina Lai Toh. — 2012-05-24T00:00:00Z

Application of wavelets to two classes of process engineering problems

Liu, Yazeng. — 2011-06-29T00:00:00Z

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

Kylie Varcoe — 2009-10-15T00:00:00Z

Application of X-ray microtomography to discrete element method simulations of agglomerate breakage

Golchert, Dennis J — 2007-08-24T00:00:00Z

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

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

Applications of forecasting and optimisation in the Australian national electricity market

Baloi, Cristian Augustus — 2007-08-24T00:00:00Z

Applications of the JIP-test of chlorophyll fluorescence

Force, Lesleigh Eileen. — 2007-08-24T00:00:00Z

Applied and molecular approaches to improving the cultivation of the tropical abalone Haliotis asinina Linnaeus

Jackson, Daniel John. — 2007-08-24T00:00:00Z

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.

Applying advanced methods to power system planning studies

Mr Guang Ya Yang — 2008-11-13T00:00:00Z

Applying Formal Methods to Software Testing

Stocks, Philip Alan — 2008-11-21T00:00:00Z

This thesis examines applying formal methods to software testing. Software testing is a critical phase of the software life-cycle which can be very effective if performed rigorously. Formal specifications offer the bases for rigorous testing practices. Not surprisingly, the most immediate use of formal specifications in software testing is as sources of black-box test suites. However, formal specifications have more uses in software testing than merely being sources for test data. We examine these uses, and show how to get more assistance and benefit from formal methods in software testing. At the core of this work is a exible framework in which to conduct specification-based testing. The framework is founded on formal definitions of tests and test suites, which directly addresses important issues in managing software testing. This provides a uniform platform for other applications of formal methods to testing such as analysis and reification of tests, and also for applications beyond testing such as maintenance and specification validation. The framework has to be exible so that any testing strategies can be used. We examine the need to adapt certain strategies to work with the framework and formal specification. Our experiments showed some deficiencies that arise when using derivation strategies on abstract specifications. These deficiencies led us to develop two new specification-based testing strategies based on extensions to existing strate- gies. We demonstrate the framework, strategies, and other applications of formal methods to software testing using three case studies. In each of these, the framework was easy to use. It provided an elegant and powerful means for defining and structuring tests, and a suitable staging ground for other applications of formal methods to software testing. This thesis demonstrates how formal specification techniques can systematise the application of testing strategies, and also how the concepts of software testing can be combined with formal specifications to extend the role of the formal specification in software development.

Approaches to Performance in Chopin’s Mazurkas: A critical commentary on selected mazurkas with specific reference to dance types, rubato and ornamentation

Thi Thanh Hang Nguyen — 2012-03-02T00:00:00Z

Performance aspects of Chopin’s Mazurkas are considered from the point of view of their relationship to: characteristics of the original peasant dance forms, Chopin’s concept of rubato, and the correct interpretation of ornamentation. Early chapters establish a range of parameters relating to the concepts within which the interpretation of the Mazurkas may operate. Subsequent chapters explore the application and understanding of these interpretative limits through an increasingly detailed focus, culminating in a critical discussion of the Mazurka in A minor, op. 17, no. 4. Findings suggest ways in which interpretative freedom and originality may be tempered by a careful consideration of the parameters outlined. Both current and historical sources are considered.

Approaches to the identification of genes for schizophrenia

Taylor, Jennifer M. — 2011-09-05T00:00:00Z

Approach to Ecological Mission in and Through the Christian Community in Australia: Beyond Apathy to Committed Action

Clive Ayre — 2009-02-10T00:00:00Z

The thesis sets out to consider the role of the Christian Church in the context of the emergent ecological crisis. The essential context for such a study is twofold. First, within the Australian Church there is clearly a dominant emphasis on an anthropocentric mission strategy, and consequently it will be argued that such a position is inadequate. Second, it will be argued that it can almost be taken as a “given” that the ecological or environmental crisis facing life on planet Earth is immediate and critical, and covers a range of well-documented categories – global warming, extreme weather events, degradation of the soil, and other factors. The loss of bio-diversity is gathering pace, while the threat to iconic features such as the Great Barrier Reef is very real. Even just from a pragmatic or humanitarian point of view, it seems important for the Christian Church to be part of a global response. From that background the thesis proceeds in three essential stages. The first issue is the identification of a sound ecological theology, or ecotheology. From the background of a large and increasing volume of literature, a range of both human-centred and eco-friendly theological positions is considered, concluding with an argument in favour of theistic biocentrism, but acknowledging that a responsible Christian environmental response may emerge from other theological positions. Thus, the thesis proposes that in addition to the scientific evidence, there is a compelling theological argument for Christian action in caring for the environment as God’s creation, and this represents a clear rationale for eco-mission. In the second part, the issue that is considered is the range of existing theologies of mission. This literature has tended to be strongly anthropocentric and very weak in the ecological area; however, there is an increasing volume of literature demonstrating a shift in emphasis towards an enhanced awareness of an ecological dimension, and in identifying that trend the thesis seeks to develop an eco-mission theology. However, there is still a perception in many congregations and denominations that ecology is not really part of the Church’s agenda. While practical action guidance models are not common, this thesis aims to challenge such a perception, and to change the culture of apathy and non-involvement in building on a foundation of ecotheology and a theology of eco-mission. Third, the thesis then explores the range and extent of Christian eco-mission, beginning with a study of how that is practised in England, and continuing with a comparative study of emerging eco-mission activity in Australia. Thus, it addresses the fundamental question as to why Christian denominations (and, by implication, local congregations) are not more actively involved in ecological mission, and explore possibilities for that position to be changed. The thesis is set within a practical theology paradigm, and employs a qualitative methodology. This involves a series of interviews supplemented by written comments and personal observations, from which dominant themes will be drawn and analysed. Thus the thesis is designed to help the Christian community to understand the seriousness of the situation as well as the biblical and theological rationale for appropriate action in “the greening of mission” and the establishment of an Australian eco-church model. In grasping the ecological aspects of its divine charter in caring for God’s creation, the Church may operate with greater confidence alongside other concerned people and groups in the community.

Approximation and exploration of streaming time series data

Xie, Qing — 2013-03-19T17:14:49Z

A pragmatic and semantic study of the Chinese modal particle A

Wang, Ying Xian — 2008-11-21T00:00:00Z

A preventative approach for minimising the impact of attrition in longitudinal studies

David, Michael Costan — 2013-03-07T16:17:38Z

'A prince of much and various knowledge, and curious observation' : Charles II's cultural interests through his collecting

Helman, Susannah — 2007-08-24T00:00:00Z