Damage identification and condition assessment of building structures using frequency response functions and neural networks

This thesis investigated the viability of using Frequency Response Functions in combination with Artificial Neural Network technique in damage assessment of building structures. The proposed approach can help overcome some of limitations associated with previously developed vibration based methods and assist in delivering more accurate and robust damage identification results. Excellent results are obtained for damage identification of the case studies proving that the proposed approach has been developed successfully.

Calibration of the electron volt spectrometer, a deep inelastic neutron scattering spectrometer at the ISIS pulsed neutron spallation source

The electron Volt Spectrometer (eVS) is an inverse geometry filter difference spectrometer that has been optimised to measure the single atom properties of condensed matter systems using a technique known as Neutron Compton Scattering (NCS) or Deep Inelastic Neutron Scattering (DINS). The spectrometer utilises the high flux of epithermal neutrons that are produced by the ISIS neutron spallation source enabling the direct measurement of atomic momentum distributions and ground state kinetic energies. In this paper the procedure that is used to calibrate the spectrometer is described. This includes details of the method used to determine detector positions and neutron flight path lengths as well as the determination of the instrument resolution. Examples of measurements on 3 different samples are shown, ZrH2, 4He and Sn which show the self-consistency of the calibration procedure.

Utilisation of hospital emergency departments among immigrants from refugee source-countries in Queensland

Despite the increasing number of immigrants, there is a limited body of literature describing the use of hospital emergency department (ED) care by immigrants in Australia. This study aims to describe how immigrants from refugee source countries (IRSC) utilise ED care, compared to immigrants from the main English speaking countries (MESC), immigrants from other countries (IOC) and the local population in Queensland. A retrospective analysis of a Queensland state-wide hospital ED dataset (ED Information System) from 1-1-2008 to 31-12-2010 was conducted. Our study showed that immigrants are not a homogenous group. We found that immigrants from IRSC are more likely to use interpreters (8.9%) in the ED compared to IOC. Furthermore, IRSC have a higher rate of ambulance use (odds ratio 1.2, 95% confidence interval (CI) 1.2–1.3), are less likely to be admitted to the hospital from the ED (odds ratio 0.7 (95% CI 0.7–0.8), and have a longer length of stay (LOS; mean differences 33.0, 95% CI 28.8–37.2), in minutes, in the ED compared to the Australian born population. Our findings highlight the need to develop policies and educational interventions to ensure the equitable use of health services among vulnerable immigrant populations.

Strategies for improved disease resistance in micro-propagated bananas

Bananas (Musa sp) are one of the most important food crops in the world and provide a staple food and source of income in many households especially in Africa. Diseases are a major constraint to production with bunchy top, caused by Banana bunchy top virus (BBTV) generally considered the most important virus disease of bananas worldwide. Of the fungal diseases, Fusarium wilt, caused by the Fusarium oxysporum f.sp cubense (Foc), and black Sigatoka, caused by Mycosphaerella fijiensis, are arguably two of the most important and cause significant yield losses. The low fertility of commercially important banana cultivars has hampered efforts to generate disease resistance using conventional breeding. Possible alternative strategies to generate or increase disease resistance are through genetic engineering or by manipulation of the innate plant defence mechanisms, namely systemic acquired resistance (SAR). The first research component of this thesis describes attempts to generate BBTV-resistant banana plants using a genetic modification approach. The second research component of the thesis focused on the identification of a potential marker gene associated with SAR in banana plants and a comparison of the expression levels of the marker gene in response to biotic and abiotic stresses, and chemical inducers. Previous research at QUT CTCB showed that replication of BBTV DNA components in banana embryogenic cell suspensions (ECS) was abolished following co-bombardment with 1.1mers of mutated BBTV DNA-R. BBTV DNA-R encodes the master replication protein (Rep) and is the only viral protein essential for BBTV replication. In this study, ECS of banana were stably transformed with the same constructs, each containing a different mutation in BBTV DNA-R, namely H41G, Y79F and K187M, to examine the effect on virus replication in stably transformed plants. Cells were also transformed with a construct containing a native BBTV Rep. A total of 16, 16, 11 and five lines of stably transformed banana plants containing the Y79F, H41G, K187M and native Rep constructs, respectively, were generated. Of these, up to nine replicates from Y79F lines, four H41G lines, seven K187M lines and three native Rep lines were inoculated with BBTV by exposure to viruliferous aphids in two separate experiments. At least one replicate from each of the nine Y79F lines developed typical bunchy top symptoms and all tested positive for BBTV using PCR. Of the four H41G lines tested, at least one replicate from three of the lines showed symptoms of bunchy top and tested positive using PCR. However, none of the five replicates of one H41G line (H41G-3) developed symptoms of bunchy top and none of the plants tested positive for BBTV using PCR. Of the seven K187M lines, at least one replicate of all lines except one (K187M-1) developed symptoms of bunchy top and tested positive for BBTV. Importantly, none of the four replicates of line K187M-1 showed symptoms or tested positive for BBTV. At least one replicate from each of the three native Rep lines developed symptoms and tested positive for BBTV. The H41G-3 and K187M-1 lines possibly represent the first transgenic banana plants generated using a mutated Rep strategy. The second research component of this thesis focused on the identification of SAR-associated genes in banana and their expression levels in response to biotic and abiotic stresses and chemical inducers. The impetus for this research was the observation that tissue-cultured (TC) banana plants were more susceptible to Fusarium wilt disease (and possibly bunchy top disease) than plants grown from field-derived suckers, possibly due to decreased levels of SAR gene expression in the former. In this study, the pathogenesis-related protein 1 (PR-1) gene was identified as a potential marker for SAR gene expression in banana. A quantitative real-time PCR assay was developed and optimised in order to determine the expression of PR-1, with polyubiquitin (Ubi-1) found to be the most suitable reference gene to enable relative quantification. The levels of PR-1 expression were subsequently compared in Lady Finger and Cavendish (cv. Williams) banana plants grown under three different environmental conditions, namely in the field, the glass house and in tissue-culture. PR-1 was shown to be expressed in both cultivars growing under different conditions. While PR-1 expression was highest in the field grown bananas and lowest in the TC bananas in Lady Finger cultivar, this was not the case in the Cavendish cultivar with glass house plants exhibiting the lowest PR-1 expression compared with tissue culture and field grown plants. The important outcomes of this work were the establishment of a qPCR-based assay to monitor PR-1 expression levels in banana and a preliminary assessment of the baseline PR-1 expression levels in two banana cultivars under three different growing conditions. After establishing the baseline PR-1 expression levels in Cavendish bananas, a study was done to determine whether PR-1 levels could be increased in these plants by exposure to known banana pathogens and non-pathogens, and a known chemical inducer of SAR. Cavendish banana plants were exposed to pathogenic Foc subtropical race 4 (FocSR4) and non-pathogenic Foc race 1 (Foc1), as well as two putative inducers of resistance, Fusarium lycopersici (Fol) and the chemical, acibenzolar-S-methyl (BION®). Tissue culture bananas were acclimatised under either glass house (TCS) or field (TCH) conditions and treatments were carried out in a randomised complete block design. PR-1 expression was determined using qPCR for both TCS and TCH samples for the period 12-72h post-exposure. Treatment of TCH plants using Foc1 and FocSR4 resulted in 120 and 80 times higher PR-1 expression than baseline levels, respectively. For TCS plants treated with Foc1, PR-1 expression was 30 times higher than baseline levels at 12h post-exposure, while TCS plants treated with FocSR4 showed the highest PR-1 expression (20 times higher than baseline levels) at 72h post-exposure. Interestingly, when TCS plants were treated with Fol there was a marked increase of PR-1 expression at 12 h and 48 h following treatment which was 4 and 8 times higher than the levels observed when TCS plants were treated with Foc1 and FocSR4, respectively. In contrast, when TCH plants were treated with Fol only a slight increase in PR-1 expression was observed at 12 h, which eventually returned to baseline levels. Exposure of both TCS and TCH plants to BION® resulted in no effect on PR-1 expression levels at any time-point. The major outcome of the SAR study was that the glass house acclimatised tissue culture bananas exhibited lower PR-1 gene expression compared to field acclimatised tissue culture plants and the identification of Fol as a good candidate for SAR induction in banana plants exhibiting low PR-1 levels. A number of outcomes that foster understanding of both pathogen-derived and plant innate resistance strategies in order to potentially improve banana resistance to diseases were explored in this study and include identification of potential inducers of systemic acquired resistance and a promising mutated Rep approach for BBTV resistance. The work presented in this thesis is the first report on the generation of potential BBTV resistant bananas using the mutated Rep approach. In addition, this is the first report on the status of SAR in banana grown under different conditions of exposure to the biotic and abiotic environment. Further, a robust qPCR assay for the study of gene expression using banana leaf samples was developed and a potential inducer of SAR in tissue culture bananas identified which could be harnessed to increase resistance in tissue culture bananas.

Examining young recreational sportswomen's intentions to engage in sun-protective behavior : the role of group and image norms

Researchers examined the sun-protective intentions and behavior of young, Caucasian, Australian sportswomen aged between 17 and 35 years (N = 100). The study adopted a 2 x 2 experimental design, comparing group norms (supportive vs. non-supportive) and image norms (tanned vs. pale) related to sun protection and taking into account group identification with friends and peers in the sport. While no significant findings emerged involving image norms, regression analyses revealed a significant two-way interaction for group norm x identification on recreational sportswomen's intentions to engage in sun protection in the next fortnight. Participants identifying strongly with their group had stronger intentions to engage in sun protection when exposed to a norm reflecting fellow recreational sportswomen engaging in sun-protective actions in comparison to those exposed to a non-supportive group. In addition, while prior intentions to engage in sun protection were not significantly related to sun-protection behavior, post-manipulation intentions after exposure to the sun-protective information that was provided were significantly related to follow-up behavior. Overall, the findings supported the importance of group-based social influences, rather than tanned media images, on sun-protective decisions among young recreational sportswomen and provided a targeted source for intervention strategies encouraging sun safety among this at-risk group for repeated sun exposure.

Gestational Diabetes Mellitus in Far North Queensland, Australia, 2004 to 2010 : midwives’ perinatal data most accurate source

Objectives: This study examines the accuracy of Gestational Diabetes Mellitus (GDM) case-ascertainment in routinely collected data. Methods: Retrospective cohort study analysed routinely collected data from all births at Cairns Base Hospital, Australia, from 1 January 2004 to 31 December 2010 in the Cairns Base Hospital Clinical Coding system (CBHCC) and the Queensland Perinatal Data Collection (QPDC). GDM case ascertainment in the National Diabetes Services Scheme (NDSS) and Cairns Diabetes Centre (CDC) data were compared. Results: From 2004 to 2010, the specificity of GDM case-ascertainment in the QPDC was 99%. In 2010, only 2 of 225 additional cases were identified from the CDC and CBHCC, suggesting QPDC sensitivity is also over 99%. In comparison, the sensitivity of the CBHCC data was 80% during 2004–2010. The sensitivity of CDC data was 74% in 2010. During 2010, 223 births were coded as GDM in the QPDC, and the NDSS registered 247 women with GDM from the same postcodes, suggesting reasonable uptake on the NDSS register. However, the proportion of Aboriginal and Torres Strait Islander women was lower than expected. Conclusion: The accuracy of GDM case ascertainment in the QPDC appears high, with lower accuracy in routinely collected hospital and local health service data. This limits capacity of local data for planning and evaluation, and developing structured systems to improve post-pregnancy care, and may underestimate resources required. Implications: Data linkage should be considered to improve accuracy of routinely collected local health service data. The accuracy of the NDSS for Aboriginal and Torres Strait Islander women requires further evaluation.

Identification of molecular genetic factors that influence migraine

Migraine is a common neurological disorder with a strong genetic basis. However, the complex nature of the disorder has meant that few genes or susceptibility loci have been identified and replicated consistently to confirm their involvement in migraine. Approaches to genetic studies of the disorder have included analysis of the rare migraine subtype, familial hemiplegic migraine with several causal genes identified for this severe subtype. However, the exact genetic contributors to the more common migraine subtypes are still to be deciphered. Genome-wide studies such as genome-wide association studies and linkage analysis as well as candidate genes studies have been employed to investigate genes involved in common migraine. Neurological, hormonal and vascular genes are all considered key factors in the pathophysiology of migraine and are a focus of many of these studies. It is clear that the influence of individual genes on the expression of this disorder will vary. Furthermore, the disorder may be dependent on gene–gene and gene–environment interactions that have not yet been considered. In addition, identifying susceptibility genes may require phenotyping methods outside of the International Classification of Headache Disorders II criteria, such as trait component analysis and latent class analysis to better define the ambit of migraine expression.

A molecular genetic approach for forensic animal species identification

This study investigated potential markers within chromosomal, mitochondrial DNA (mtDNA) and ribosomal RNA (rRNA) with the aim of developing a DNA based method to allow differentiation between animal species. Such discrimination tests may have important applications in the forensic science, agriculture, quarantine and customs fields. DNA samples from five different animal individuals within the same species for 10 species of animal (including human) were analysed. DNA extraction and quantitation followed by PCR amplification and GeneScan visualisation formed the basis of the experimental analysis. Five gene markers from three different types of genes were investigated. These included genomic markers for the β-actin and TP53 tumor suppressor gene. Mitochondrial DNA markers, designed by Bataille et al. [Forensic Sci. Int. 99 (1999) 165], examined the Cytochrome b gene and Hypervariable Displacement Loop (D-Loop) region. Finally, a ribosomal RNA marker for the 28S rRNA gene optimised by Naito et al. [J. Forensic Sci. 37 (1992) 396] was used as a possible marker for speciation. Results showed a difference of only several base pairs between all species for the β-actin and 28S markers, with the exception of Sus scrofa (pig) β-actin fragment length, which produced a significantly smaller fragment. Multiplexing of Cytochrome b and D-Loop markers gave limited species information, although positive discrimination of human DNA was evident. The most specific and discriminatory results were shown using the TP53 gene since this marker produced greatest fragment size differences between animal species studied. Sample differentiation for all species was possible following TP53 amplification, suggesting that this gene could be used as a potential animal species identifier.

Identification and simultaneous analysis of harmane, harmol, isovitexin and vitexin in Passiflora incarnata extracts with a novel HLPC method

A high performance liquid chromatographic method for the simultaneous analysis of two flavonoids (iso-vitexin and vitexin), and three indole alkaloids (harmane, harmine, and harmol) was developed. This method was then utilised to quantitate levels of these five constituents in methanolic extracts of Australian Passiflora incarnata. HPLC analysis was performed using a Waters™ Novapak C18 (150 × 4 mm, 4 μm) column, with a gradient solvent system of methanol-water-acetic acid. Detection was achieved by PDA UV (254 nm) and fluorescence (excitation 254 nm, emission 414 nm), utilising the external standard method to obtain quantification.

Impact of a school-based food garden on attitudes and identification skills regarding vegetables and fruit : a 12-month intervention trial

Objective To determine changes in ability to identify specific vegetables and fruits, and attitudes towards vegetables and fruit, associated with the introduction of a school-based food garden. Design A 12-month intervention trial using a historical control (control n 132, intervention n 120), class-based, self-administered questionnaires requiring one-word answers and 3-point Likert scale responses. Setting A state primary school (grades 4 to 7) in a low socio-economic area of Brisbane, Australia. Intervention The introduction of a school-based food garden, including the funding of a teacher coordinator for 11 h/week to facilitate integration of garden activities into the curriculum. Main outcome measures Ability to identify a series of vegetables and fruits, attitudes towards vegetables and fruit. Analysis Frequency distributions for each item were generated and χ2 analyses were used to determine statistical significance. Exploratory factor analysis was employed to detect major trends in data. Results The intervention led to enhanced ability to identify individual vegetables and fruits, greater attention to origins of produce (garden-grown and fresh), changes to perceived consumption of vegetables and fruits, and enhanced confidence in preparing fruit and vegetable snacks, but decreased interest in trying new fruits. Conclusions The introduction of this school-based food garden was associated with skill and attitudinal changes conducive to enhancing vegetable and fruit consumption. The ways in which such changes might impact on dietary behaviours and intake require further analysis.

BoP and MNCs: where is the market and where the source of innovation?

ln 2004 Prahalad made managers aware of the great economic opportunity that the population at the BoP (Base of the Pyramid) could represent for business in the tom of new potential consumers. However, MNCs (Multi-National Corporations) have continued to fail in penetrating low income markets, arguably because applied strategies are often the same adopted at the top of the pyramid. Even in those few cases where products get re-envisioned, theie introduction in contexts of extreme poverty only induces new needs and develops new dependencies. At best the rearrangement of business models by MNCs has meant the realization of CSR (Corporate Social Responsibly) schemes that have validity from a marketing perspective, but still lack the crucial element of social embeddedness (London & Hart, 2004). Today the challenge is lo reach the lowest population tier with reinvented business models based on principles of value co-creation. Starting from a view of the potential consumer at the BoP as a ring of continuity in the value chain process – a resource that can itself produce value - this paper concludes proposing an alternative innovative approach to operate in developing markets that overturns the roles of MNCs and the BoP. The proposed perspective of ‘reversed' source of innovation and primary target market builds on two fundamental tenets: traditional knowledge is rich and greatly unexploded, and markets at the lop of the pyramid are saturated with unnecessary products / practices that have lost contact with the natural environment.

BoP and MNCs: where is the market and where the source of innovation?

ln 2004 Prahalad made managers aware of the great economic opportunity that the population at the BoP (Base of the Pyramid) could represent for business in the tom of new potential consumers. However, MNCs (Multi-National Corporations) have continued to fail in penetrating low income markets, arguably because applied strategies are often the same adopted at the top of the pyramid. Even in those few cases where products get re-envisioned, theie introduction in contexts of extreme poverty only induces new needs and develops new dependencies. At best the rearrangement of business models by MNCs has meant the realization of CSR (Corporate Social Responsibly) schemes that have validity from a marketing perspective, but still lack the crucial element of social embeddedness (London & Hart, 2004). Today the challenge is lo reach the lowest population tier with reinvented business models based on principles of value co-creation. Starting from a view of the potential consumer at the BoP as a ring of continuity in the value chain process – a resource that can itself produce value - this paper concludes proposing an alternative innovative approach to operate in developing markets that overturns the roles of MNCs and the BoP. The proposed perspective of ‘reversed' source of innovation and primary target market builds on two fundamental tenets: traditional knowledge is rich and greatly unexploded, and markets at the lop of the pyramid are saturated with unnecessary products / practices that have lost contact with the natural environment.

Human identification at a distance using iris and face

This research has successfully applied super-resolution and multiple modality fusion techniques to address the major challenges of human identification at a distance using face and iris. The outcome of the research is useful for security applications.

First measurements of source apportionment of organic aerosols in the Southern Hemisphere

An Aerodyne Aerosol Mass Spectrometer was deployed at five urban schools to examine spatial and temporal variability of organic aerosols (OA) and positive matrix factorization (PMF) used for the first time in the Southern Hemisphere to apportion the sources of the OA across an urban area. The sources identified included hydrocarbon-like OA (HOA), biomass burning OA (BBOA) and oxygenated OA (OOA). At all sites, the main source was OOA, which accounted for 62–73% of the total OA mass and was generally more oxidized compared to those reported in the Northern Hemisphere. This suggests that there are differences in aging processes or regional sources in the two hemispheres. Unlike HOA and BBOA, OOA demonstrated instructive temporal variations but not spatial variation across the urban area. Application of cluster analysis to the PMF-derived sources offered a simple and effective method for qualitative comparison of PMF sources that can be used in other studies.

Improving short utterance based I-vector speaker recognition using source and utterance-duration normalization techniques

A significant amount of speech is typically required for speaker verification system development and evaluation, especially in the presence of large intersession variability. This paper introduces a source and utterance duration normalized linear discriminant analysis (SUN-LDA) approaches to compensate session variability in short-utterance i-vector speaker verification systems. Two variations of SUN-LDA are proposed where normalization techniques are used to capture source variation from both short and full-length development i-vectors, one based upon pooling (SUN-LDA-pooled) and the other on concatenation (SUN-LDA-concat) across the duration and source-dependent session variation. Both the SUN-LDA-pooled and SUN-LDA-concat techniques are shown to provide improvement over traditional LDA on NIST 08 truncated 10sec-10sec evaluation conditions, with the highest improvement obtained with the SUN-LDA-concat technique achieving a relative improvement of 8% in EER for mis-matched conditions and over 3% for matched conditions over traditional LDA approaches.