Speaker verification using I-vector features

This PhD research has provided novel solutions to three major challenges which have prevented the wide spread deployment of speaker recognition technology: (1) combating enrolment/ verification mismatch, (2) reducing the large amount of development and training data that is required and (3) reducing the duration of speech required to verify a speaker. A range of applications of speaker recognition technology from forensics in criminal investigations to secure access in banking will benefit from the research outcomes.

Development and characterization of a novel, antimicrobial, sterile hydrogel dressing for burn wounds : single-step production with gamma irradiation creates silver nanoparticles and radical polymerization

Patients with burn wounds are susceptible to wound infection and sepsis. This research introduces a novel burn wound dressing that contains silver nanoparticles (SNPs) to treat infection in a 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na(+) ) hydrogel. Silver nitrate was dissolved in AMPS-Na(+) solution and then exposed to gamma irradiation to form SNP-infused hydrogels. The gamma irradiation results in a cross-linked polymeric network of sterile hydrogel dressing and a reduction of silver ions to form SNPs infused in the hydrogel in a one-step process. About 80% of the total silver was released from the hydrogels after 72 h immersion in simulated body fluid solution; therefore, they could be used on wounds for up to 3 days. All the hydrogels were found to be nontoxic to normal human dermal fibroblast cells. The silver-loaded hydrogels had good inhibitory action against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. Results from a pilot study on a porcine burn model showed that the 5-mM silver hydrogel was efficient at preventing bacterial colonization of wounds, and the results were comparable to the commercially available silver dressings (Acticoat(TM) , PolyMem Silver(®) ). These results support its use as a potential burn wound dressing.

Cytotoxicity testing of silver-containing burn treatments using primary and immortal skin cells

A novel burn wound hydrogel dressing has been previously developed which is composed of 2-acrylamido-2-methylpropane sulfonic acid sodium salt with silver nanoparticles (silver AMPS). This study compared the cytotoxicity of this dressing to the commercially available silver products; Acticoat™, PolyMem Silver® and Flamazine™ cream. Human keratinocytes (HaCaT and primary HEK) and normal human fibroblasts (NHF) were exposed to dressings incubated on Nunc™ polycarbonate inserts for 24, 48 and 72h. Four different cytotoxicity assays were performed including; Trypan Blue cell count, MTT, Celltiter-Blue™ and Toluidine Blue surface area assays. The results were expressed as relative cell viability compared to an untreated control. The cytotoxic effects of Acticoat™ and Flamazine™ cream were dependent on exposure time and cell type. After 24h exposure, Acticoat™ and Flamazine™ cream were toxic to all tested cell lines. Surprisingly, HaCaTs treated with Acticoat™ and Flamazine™ had an improved ability to survive at 48 and 72h while HEKs and NHFs had no improvement in survival with any treatment. The novel silver hydrogel and PolyMem Silver® showed low cytotoxicity to all tested cell lines at every time interval and these results support the possibility of using the novel silver hydrogel as a burn wound dressing. Researchers who rely on HaCaT cells as an accurate keratinocyte model should be aware that they can respond differently to primary skin cells.

Qld flood inquest : ‘I could see his arms moving, he was trying to swim’

"Despite the 10 months of grieving for those lost in Queensland’s January floods, new evidence produced during the coronial inquest into the 22 deaths and three disappearances has revealed new shocks for the bereaved families. Brisbane Coroner’s Court yesterday was introduced to a series of high-tech Google Earth animations backed by funereal music, explaining the scope of the unfolding tragedy, which swept away husbands, wives, children and grandparents in less than three hours on the afternoon of January 10 this year. The court was also told of the extensive search for human remains, of 131 kilometres of creeks and rivers from Spring Bluff to Brisbane and hundreds of dams that were searched three times by police divers, 250 army personnel and 200 police."

New Dawn (Parts I & II)

New Dawn is a cross-media visual art project that comprises a multi–channel video work (Boxcopy ARI, Brisbane) and a series of sculptural works (MetroArts, Brisbane) both of which conflate the online spectacle of real events with virtual gaming. The purpose of this project is to question this new phenomenon and what are the political, social and economic repercussions for these new technological developments on our bodies and subjectivities. By doing this my work asks us to reflect on how we function as a society in response to these new spaces of interaction, how we might respond to the political dimensions of these expanded sites of inhabitation, and how they might also represent a more troubling scenario for the possibility of dissent or opposition in our media saturated culture. The work was shown at multiple venues simultaneously. One of the components of the work won the 2013 Sunshine Coast Art Prize for sculpture.

Prevalence and clinical outcomes for patients with ALK-positive resected stage I to III adenocarcinoma : results from the European Thoracic Oncology Platform Lungscape Project

PURPOSE: The prevalence of anaplastic lymphoma kinase (ALK) gene fusion (ALK positivity) in early-stage non-small-cell lung cancer (NSCLC) varies by population examined and detection method used. The Lungscape ALK project was designed to address the prevalence and prognostic impact of ALK positivity in resected lung adenocarcinoma in a primarily European population. METHODS: Analysis of ALK status was performed by immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) in tissue sections of 1,281 patients with adenocarcinoma in the European Thoracic Oncology Platform Lungscape iBiobank. Positive patients were matched with negative patients in a 1:2 ratio, both for IHC and for FISH testing. Testing was performed in 16 participating centers, using the same protocol after passing external quality assessment. RESULTS: Positive ALK IHC staining was present in 80 patients (prevalence of 6.2%; 95% CI, 4.9% to 7.6%). Of these, 28 patients were ALK FISH positive, corresponding to a lower bound for the prevalence of FISH positivity of 2.2%. FISH specificity was 100%, and FISH sensitivity was 35.0% (95% CI, 24.7% to 46.5%), with a sensitivity value of 81.3% (95% CI, 63.6% to 92.8%) for IHC 2+/3+ patients. The hazard of death for FISH-positive patients was lower than for IHC-negative patients (P = .022). Multivariable models, adjusted for patient, tumor, and treatment characteristics, and matched cohort analysis confirmed that ALK FISH positivity is a predictor for better overall survival (OS). CONCLUSION: In this large cohort of surgically resected lung adenocarcinomas, the prevalence of ALK positivity was 6.2% using IHC and at least 2.2% using FISH. A screening strategy based on IHC or H-score could be envisaged. ALK positivity (by either IHC or FISH) was related to better OS.

“I’m Happy with Who I Am” : A Discursive Analysis of the Self-characterisation Practices of Boys in “Behaviour” Schools

In this chapter, I draw on poststructural theories of language to examine the self-characterisation practices of 33 boys attending special schools for students with disruptive behaviour. During a semi-structured interview, each boy was asked to describe his personality and then to choose from a selection of positive/negative word pairs. The objective was to determine whether these young people would characterise themselves in positive or negative ways. Participants were then asked if there was anything they would change about themselves if they could. Responses were analysed and compared against a discourse model developed from media reports and interviews with their principals. Findings suggest that while discourse may well ‘form the objects of which it speaks’ (Foucault, 1972, p. 49) in the eyes of teachers, principals, psychiatrists and paediatricians, it also offers a means through which the constituted subject can re-author itself in a more positive frame.

Nanostructured silver-gold bimetallic SERS substrates for selective identification of bacteria in human blood

Surface-enhanced Raman spectroscopy (SERS) is a potentially important tool in the rapid and accurate detection of pathogenic bacteria in biological fluids. However, for diagnostic application of this technique, it is necessary to develop a highly sensitive, stable, biocompatible and reproducible SERS-active substrate. In this work, we have developed a silver–gold bimetallic SERS surface by a simple potentiostatic electrodeposition of a thin gold layer on an electrochemically roughened nanoscopic silver substrate. The resultant substrate was very stable under atmospheric conditions and exhibited the strong Raman enhancement with the high reproducibility of the recorded SERS spectra of bacteria (E. coli, S. enterica, S. epidermidis, and B. megaterium). The coating of the antibiotic over the SERS substrate selectively captured bacteria from blood samples and also increased the Raman signal in contrast to the bare surface. Finally, we have utilized the antibiotic-coated hybrid surface to selectively identify different pathogenic bacteria, namely E. coli, S. enterica and S. epidermidis from blood samples.

Regenerative silver nanoparticles for SERRS investigation of metmyoglobin with conserved heme pocket

Shell isolated silver nanoparticles with an ultrathin silica layer (Ag@SiO2NPs) are used as a surface-enhanced resonance Raman scattering (SERRS) substrate for probing metmyoglobin (metMb) in aqueous solution. The ultrathin silica layer protects metMb from reaching the bare silver surface and conserves the heme pocket during SERRS analysis with a Raman enhancement factor (EFSERS) of 4.78 × 104. In spite of the good SERRS enhancement, the interaction between the protein and Ag@SiO2NPs is weak enough to separate them by centrifugation in such a way that both are regenerated in their original form and can be reused. Using Ag@SiO2NPs as the SERRS substrate, the lowest detection limit of 2 nM was achieved for metMb whilst conserving the native structure of the heme centre.

Plasmon-tuned silver colloids for SERRS analysis of methemoglobin with preserved nativity

Optically tuned silver nanoparticles (AgNP's) functionalized with ω-mercaptoalkanoic acids are synthesized and used as a signal amplifier for the surface-enhanced resonance Raman scattering (SERRS) study of heme cofactor in methemoglobin (metHb). Even though both mercaptopropionic acid (MPA)- and mercaptononanoic acid (MNA)-functionalized AgNP's exemplify vastly enhanced SERRS signal of metHb, MNA-AgNP's amplify the SERRS signal amid preservation of the nativity of the heme pocket, unlike MPA-AgNP's. The electrostatic interaction between MNA-AgNP's and metHb leads to instant signal enhancement with a Raman enhancement factor (EF(SERS)) of 4.2 × 10(3). Additionally, a Langmuir adsorption isotherm has been employed for the adsorption of metHb on the MNA-AgNP surface, which provides the real surface coverage and equilibrium constant (K) of metHb as 139 nM and 3.6 × 10(8) M(-1), respectively. The lowest detection limit of 10 nM for metHb has been demonstrated using MNA-AgNP's besides retaining the nativity of the heme pocket.

Characterization of acyl chain position in unsaturated phosphatidylcholines using differential mobility-mass spectrometry

Glycerophospholipids (GPs) that differ in the relative position of the two fatty acyl chains on the glycerol backbone (i.e., sn-positional isomers) can have distinct physicochemical properties. The unambiguous assignment of acyl chain position to an individual GP represents a significant analytical challenge. Here we describe a workflow where phosphatidylcholines (PCs) are subjected to ESI for characterization by a combination of differential mobility spectrometry and MS (DMS-MS). When infused as a mixture, ions formed from silver adduction of each phospholipid isomer {e.g., [PC (16:0/18:1) + Ag]+ and [PC (18:1/16:0) + Ag]+} are transmitted through the DMS device at discrete compensation voltages. Varying their relative amounts allows facile and unambiguous assignment of the sn-positions of the fatty acyl chains for each isomer. Integration of the well-resolved ion populations provides a rapid method (< 3 min) for relative quantification of these lipid isomers. The DMS-MS results show excellent agreement with established, but time-consuming, enzymatic approaches and also provide superior accuracy to methods that rely on MS alone. The advantages of this DMS-MS method in identification and quantification of GP isomer populations is demonstrated by direct analysis of complex biological extracts without any prior fractionation.

“I would have lost the respect of my friends and family if they knew I had bent the road rules” : parents, peers, and the perilous behaviour of young drivers

Young novice drivers are at considerable risk of injury on the road. Their behaviour appears vulnerable to the social influence of their parents and friends. The nature and mechanisms of parent and peer influence on young novice driver (16–25 years) behaviour was explored via small group interviews (n = 21) and two surveys (n1 = 1170, n2 = 390) to inform more effective young driver countermeasures. Parental and peer influence occurred in preLicence, Learner, and Provisional (intermediate) periods. Pre-Licence and unsupervised Learner drivers reported their parents were less likely to punish risky driving (e.g., speeding). These drivers were more likely to imitate their parents and reported their parents were also risky drivers. Young novice drivers who experienced or expected social punishments from peers, including ‘being told off’ for risky driving, reported less riskiness. Conversely drivers who experienced or expected social rewards such as being ‘cheered on’ by friends – who were also more risky drivers – reported more risky driving including crashes and offences. Interventions enhancing positive influence and curtailing negative influence may improve road safety outcomes not only for young novice drivers, but for all persons who share the road with them. Parent-specific interventions warrant further development and evaluation including: modelling safe driving behaviour by parents; active monitoring of driving during novice licensure; and sharing the family vehicle during the intermediate phase. Peer-targeted interventions including modelling of safe driving behaviour and attitudes; minimisation of social reinforcement and promotion of social sanctions for risky driving also need further development and evaluation.

Recent surveys of bats (Mammalia: Chiroptera) from China. I. Rhinolophidae and Hipposideridae

We conducted surveys of bats in China between 1999 and 2007, resulting in the identification of at least 62 species. In this paper we present data on 19 species, comprising 12 species from the family Rhinolophidae and seven from the Hipposideridae. Rhinolophids captured were Rhinolophus affinis, R. ferrumequinum, R. lepidus, R. luctus, R. macrotis, R. siamensis, R. marshalli, R. rex, R. pearsonii, R. pusillus, R. sinicus and R. stheno. Because of extensive morphological similarities we question the species distinctiveness of R. osgoodi (may be conspecific with R. lepidus), R. paradoxolophus (which may best be treated as a subspecies of R. rex), R. huananus (probably synonymous with R. siamensis), and we are skeptical as to whether R. sinicus is distinct from R. thomasi. Hipposiderids captured were Hipposideros armiger, H. cineraceus, H. larvatus, H. pomona, H. pratti, Aselliscus stoliczkanus and Coelops frithii. Of these species, two rhinolophids (Rhinolophus marshalli and R. stheno) and one hipposiderid (Hipposideros cineraceus) represent new species records for China. We present data on species' ranges, morphology and echolocation call frequencies, as well as some notes on ecology and conservation status. China hosts a considerable diversity of rhinolophid and hipposiderid bats, yet threats to their habitats and populations are substantial.