Preliminary characterisation of tumor necrosis factor alpha and interleukin-10 responses to chlamydia pecorum infection in the koala (Phascolarctos cinereus)

Debilitating infectious diseases caused by Chlamydia are major contributors to the decline of Australia's iconic native marsupial species, the koala (Phascolarctos cinereus). An understanding of koala chlamydial disease pathogenesis and the development of effective strategies to control infections continue to be hindered by an almost complete lack of species-specific immunological reagents. The cell-mediated immune response has been shown to play an influential role in the response to chlamydial infection in other hosts. The objective of this study, hence, was to provide preliminary data on the role of two key cytokines, pro-inflammatory tumour necrosis factor alpha (TNFα) and anti-inflammatory interleukin 10 (IL10), in the koala Chlamydia pecorum response. Utilising sequence homology between the cytokine sequences obtained from several recently sequenced marsupial genomes, this report describes the first mRNA sequences of any koala cytokine and the development of koala specific TNFα and IL10 real-time PCR assays to measure the expression of these genes from koala samples. In preliminary studies comparing wild koalas with overt chlamydial disease, previous evidence of C. pecorum infection or no signs of C. pecorum infection, we revealed strong but variable expression of TNFα and IL10 in wild koalas with current signs of chlamydiosis. The description of these assays and the preliminary data on the cell-mediated immune response of koalas to chlamydial infection paves the way for future studies characterising the koala immune response to a range of its pathogens while providing reagents to assist with measuring the efficacy of ongoing attempts to develop a koala chlamydial vaccine.

The role of the Eph and ephrin proteins in prostate cancer

Prostate cancer is the most commonly diagnosed malignancy and the second leading cause of cancer related deaths in Australian men. Treatment in the early stages of the disease involves surgery, radiation and/or hormone therapy. However, in late stages of the disease these treatments are no longer effective and only palliative care is available. Therefore, there is a focus on exploration of novel therapies to increase survival and treatment efficacy. Advanced prostate cancer is characterised by bone or other distant metastasis. Spreading of the primary tumour to a secondary location is a complex process requiring an initial loss in cell-cell adhesion followed by increased cell migration and invasion. One gene family that has been known to affect cell-to-cell contact in other model systems are the Eph receptor tyrosine kinases. They are the largest family of receptor tyrosine kinases made up of 14 vertebrate Eph receptors that bind to nine cell membrane bound ephrin ligands. Eph-ephrin interaction is crucial in regulating cell behaviour in developmental processes and it is now thought that the underlying mechanisms involved in development may also be involved in cancer. Aberrant expression has been reported in many human malignancies including prostate cancer. Furthermore, expression has been linked with metastasis and poor prognosis in other tumour models. This study explores the potential role of the Eph receptor family in prostate cancer, in particular the roles of EphA2, EphA3 and ephrin-A5. Gene expression profiles were established for the Eph family in a series of prostate cancer cell lines using quantitative real time RT-PCR. A smaller subset of the most prominently expressed genes was chosen to screen a cohort of clinical samples. Elevated levels of EphA2, EphA3 and their ligands, ephrin-A1 and ephrin-A5 were observed in individual cell lines. Interestingly high EphA3 expression was observed in the androgen responsive cell lines while EphA2 was more prominent in the androgen independent cell lines. However, studies using 5-dihydrotestosterone suggest that EphA3 expression in not regulated by androgen. Cells expressing EphA2 showed a greater ability for migration and invasion while cells expressing EphA3 showed poor migration and invasion. Forced expression of EphA2 in the LNCaP cell line resulted in a more invasive phenotype while forced expression of EphA3 in the PC-3 cell line suggests a possible negative effect for EphA3 on cell migration and invasion. Cell signalling studies show activation of EphA2 decreases activity of proteins thought to be involved in pathways regulating cell movement including Akt, Src and FAK. Changes to the activation status of Rho family members, including RhoA and Rac1, associated with reorganisation of the actin cytoskeleton, an important part of cell migration was also observed. As a result, activation of EphA2 in PC-3 cells resulted in a less invasive phenotype. A novel finding in this study was the discovery of a combination of two EphA2 Mabs able to activate EphA2. Preliminary results show a potential for this antibody combination to reduce prostate cancer invasion in vitro. A unique aspect of Eph-ephrin interaction is the resulting bi-directional signalling that occurs through both the receptor and ligand. In this study a potential role for ephrin-A5 mediated signalling in prostate cancer was observed. LNCaP cells express high levels of EphA3 and its high affinity ligand ephrin-A5. In stripe assays, used to study guidance cues, LNCaP cells show strong attraction/migration to EphA3-Fc stripes but not ephrin-A5-Fc stripes suggesting ephrin-A5 mediated reverse cell signalling is involved. Knockdown of ephrin-A5 using shRNA resulted in a decrease in attraction/migration to EphA3-Fc stripes. Furthermore a reduction in proliferation was also observed in vitro. A subcutaneous xenograft model using ephrin-A5 shRNA cells versus controls showed a decrease in tumour formation. This study demonstrates a difference in EphA2 and EphA3 function in prostate cancer migration/invasion and a potential role for ephrin-A5 in prostate cancer cell adhesion and growth.

Maternal report of young children's eating styles. Validation of the Children's Eating Behaviour Questionnaire in three ethnically diverse Australian samples

The aim of this study was to validate the Children’s Eating Behaviour Questionnaire (CEBQ) in three ethnically and culturally diverse samples of mothers in Australia. Confirmatory factor analysis utilising structural equation modelling examined whether the established 8-factor model of the CEBQ was supported in our three populations: (i) a community sample of first-time mothers allocated to the control group of the NOURISH trial (mean child age = 24 months [SD = 1]; N = 244); (ii) a sample of immigrant Indian mothers of children aged 1–5 years (mean age = 34 months [SD = 14]; N = 203), and (iii) a sample of immigrant Chinese mothers of children aged 1–4 years (mean age = 36 months [SD = 14]; N = 216). The original 8-factor model provided an acceptable fit to the data in the NOURISH sample with minor post hoc re-specifications (two error covariances on Satiety Responsiveness and an item-factor covariance to account for a cross-loading of an item (Fussiness) on Satiety Responsiveness). The re-specified model showed reasonable fit in both the Indian and Chinese samples. Cronbach’s α estimates ranged from .73 to .91 in the Australian sample and .61–.88 in the immigrant samples. This study supports the appropriateness of the CEBQ in the multicultural Australian context.

Real-time image classification for adaptive mission planning using an Autonomous Underwater Vehicle

Real-time image analysis and classification onboard robotic marine vehicles, such as AUVs, is a key step in the realisation of adaptive mission planning for large-scale habitat mapping in previously unexplored environments. This paper describes a novel technique to train, process, and classify images collected onboard an AUV used in relatively shallow waters with poor visibility and non-uniform lighting. The approach utilises Förstner feature detectors and Laws texture energy masks for image characterisation, and a bag of words approach for feature recognition. To improve classification performance we propose a usefulness gain to learn the importance of each histogram component for each class. Experimental results illustrate the performance of the system in characterisation of a variety of marine habitats and its ability to operate onboard an AUV's main processor suitable for real-time mission planning.

Pulse-coupled neural network performance for real-time identification of vegetation during forced landing

Safety concerns in the operation of autonomous aerial systems require safe-landing protocols be followed during situations where the mission should be aborted due to mechanical or other failure. This article presents a pulse-coupled neural network (PCNN) to assist in the vegetation classification in a vision-based landing site detection system for an unmanned aircraft. We propose a heterogeneous computing architecture and an OpenCL implementation of a PCNN feature generator. Its performance is compared across OpenCL kernels designed for CPU, GPU, and FPGA platforms. This comparison examines the compute times required for network convergence under a variety of images to determine the plausibility for real-time feature detection.

Assessment of polybrominated diphenyl ethers (PBDEs) in samples collected from indoor environments in South East Queensland, Australia

Polybrominated diphenyl ethers (PBDEs) are compounds that are used as flame retardants. Human exposure is suggested to be via food, dust and air. An assessment of PBDE exposure via indoor environments using samples of air, dust and surface wipes from eight sites in South East Queensland, Australia was conducted. For indoor air, ΣPBDEs ranged from 0.5 -179 pg/m3 for homes and 15 - 487 pg/m3 for offices. In dust, ΣPBDEs ranged from 87 - 733 ng/g dust and 583 - 3070 ng/g dust in homes and offices, respectively. PBDEs were detected on 9 out of 10 surfaces sampled and ranged from non-detectable to 5985 pg/cm2. Overall, the congener profiles for air and dust were dominated by BDE-209. This study demonstrated that PBDEs are ubiquitous in the indoor environments of selected buildings in South East Queensland and suggest the need for detailed assessment of PBDE concentrations using more sites to further investigate the factors influencing PBDE exposure in Australia.

Pilot plant studies of ion exchange for desalination of coal seam gas produced water

This paper reports a study of ion exchange (IX) as an alternative CSG water treatment to the widely used reverse osmosis (RO) desalination process. An IX pilot plant facility has been constructed and operated using both synthetic and real CSG water samples. Application of appropriate synthetic resin technology has proved the effectiveness of IX processes.

Effect of real support conditions on the shear strength of hollow flange channel beams

This paper presents the details of experimental studies on the effect of real support conditions on the shear strength of LiteSteel beams (LSB). The LSB has a unique shape of a channel beam with two rectangular hollow flanges, made using a unique manufacturing process. In some applications in the building industry LSBs are used with only one web side plate (WSP) at their supports and are not used with full height web side plates (WSP) at their supports. Past research studies showed that theses real support connections did not provide simply supported conditions. Many studies have been carried out to evaluate the behaviour and design of LSBs with simply supported conditions subject to pure bending and predominant shear actions. To date, however, no investigation has been conducted into the effect of real support conditions on the shear strength of LSBs. Hence detailed experimental studies were undertaken to investigate the shear behaviour and strength of LSBs with real support conditions. A total of 28 experimental tests were conducted as part of the studies. Simply supported test specimens of LSBs with aspect ratios of 1.0 and 1.5 were loaded at mid-span until failure. It was found that the effect of using one WSP on the shear behaviour of LSB is significant and there is about 25% shear capacity reduction due to the lateral movement of the bottom flange at the supports. Shear capacity of LSB was also found to decrease when full height WSPs were not used. Suitable support connections were developed to improve the shear capacity of LSBs based on test results.

Repeated sequences as genetic markers in pooled tissue samples

We show, using the PDR1 element of pea, that dispersed repeated sequences of moderate copy number can be used simply and efficiently to generate markers linked to a trait of interest. Inspection of hybridization patterns of repeated sequences to DNA mixtures of pooled genotypes is a sensitive way of detecting such markers. The large number of bands in tracks of digests of these mixtures allows the simultaneous sampling of loci at many places in the genome, and the many unlinked loci serve as internal controls. It is also shown that intensity ratios calculated from these band differences can be used to give a rough estimate of linkage distance.

Quantitative stem-loop RT-PCR for detection of microRNAs

Plant microRNAs (miRNAs) are a class of endogenous small RNAs that are essential for plant development and survival. They arise from larger precursor RNAs with a characteristic hairpin structure and regulate gene activity by targeting mRNA transcripts for cleavage or translational repression. Efficient and reliable detection and quantification of miRNA expression has become an essential step in understanding their specific roles. The expression levels of miRNAs can vary dramatically between samples and they often escape detection by conventional technologies such as cloning, northern hybridization and microarray analysis. The stem-loop RT-PCR method described here is designed to detect and quantify mature miRNAs in a fast, specific, accurate and reliable manner. First, a miRNA-specific stem-loop RT primer is hybridized to the miRNA and then reverse transcribed. Next, the RT product is amplified and monitored in real time using a miRNA-specific forward primer and the universal reverse primer. This method enables miRNA expression profiling from as little as 10 pg of total RNA and is suitable for high-throughput miRNA expression analysis.

Enabling safe autonomous driving in real-world city traffic using multiple criteria decision making

This paper addresses the topic of real-time decision making for autonomous city vehicles, i.e., the autonomous vehicles' ability to make appropriate driving decisions in city road traffic situations. The paper explains the overall controls system architecture, the decision making task decomposition, and focuses on how Multiple Criteria Decision Making (MCDM) is used in the process of selecting the most appropriate driving maneuver from the set of feasible ones. Experimental tests show that MCDM is suitable for this new application area.

Methodology for developing real-time motorway traffic risk identification models using individual-vehicle data

Most of existing motorway traffic safety studies using disaggregate traffic flow data aim at developing models for identifying real-time traffic risks by comparing pre-crash and non-crash conditions. One of serious shortcomings in those studies is that non-crash conditions are arbitrarily selected and hence, not representative, i.e. selected non-crash data might not be the right data comparable with pre-crash data; the non-crash/pre-crash ratio is arbitrarily decided and neglects the abundance of non-crash over pre-crash conditions; etc. Here, we present a methodology for developing a real-time MotorwaY Traffic Risk Identification Model (MyTRIM) using individual vehicle data, meteorological data, and crash data. Non-crash data are clustered into groups called traffic regimes. Thereafter, pre-crash data are classified into regimes to match with relevant non-crash data. Among totally eight traffic regimes obtained, four highly risky regimes were identified; three regime-based Risk Identification Models (RIM) with sufficient pre-crash data were developed. MyTRIM memorizes the latest risk evolution identified by RIM to predict near future risks. Traffic practitioners can decide MyTRIM’s memory size based on the trade-off between detection and false alarm rates. Decreasing the memory size from 5 to 1 precipitates the increase of detection rate from 65.0% to 100.0% and of false alarm rate from 0.21% to 3.68%. Moreover, critical factors in differentiating pre-crash and non-crash conditions are recognized and usable for developing preventive measures. MyTRIM can be used by practitioners in real-time as an independent tool to make online decision or integrated with existing traffic management systems.