From science to management : using Bayesian networks to learn about Lyngbya

Toxic blooms of Lyngbya majuscula occur in coastal areas worldwide and have major ecological, health and economic consequences. The exact causes and combinations of factors which lead to these blooms are not clearly understood. Lyngbya experts and stakeholders are a particularly diverse group, including ecologists, scientists, state and local government representatives, community organisations, catchment industry groups and local fishermen. An integrated Bayesian Network approach was developed to better understand and model this complex environmental problem, identify knowledge gaps, prioritise future research and evaluate management options.

PITX2 and non-canonical Wnt pathway interaction in metastatic prostate cancer

The non-canonical Wnt pathway, a regulator of cellular motility and morphology, is increasingly implicated in cancer metastasis. In a quantitative PCR array analysis of 84 Wnt pathway associated genes, both non-canonical and canonical pathways were activated in primary and metastatic tumors relative to normal prostate. Expression of the Wnt target gene PITX2 in a prostate cancer (PCa) bone metastasis was strikingly elevated over normal prostate (over 2,000-fold) and primary prostate cancer (over 200-fold). The elevation of PITX2 protein was also evident on tissue microarrays, with strong PITX2 immunostaining in PCa skeletal and, to a lesser degree, soft tissue metastases. PITX2 is associated with cell migration during normal tissue morphogenesis. In our studies, overexpression of individual PITX2A/B/C isoforms stimulated PC-3 PCa cell motility, with the PITX2A isoform imparting a specific motility advantage in the presence of non-canonical Wnt5a stimulation. Furthermore, PITX2 specific shRNA inhibited PC-3 cell migration toward bone cell derived chemoattractant. These experimental results support a pivotal role of PITX2A and non-canonical Wnt signaling in enhancement of PCa cell motility, suggest PITX2 involvement in homing of PCa to the skeleton, and are consistent with a role for PITX2 in PCa metastasis to soft and bone tissues. Our findings, which significantly expand previous evidence that PITX2 is associated with risk of PCa biochemical recurrence, indicate that variation in PITX2 expression accompanies and may promote prostate tumor progression and metastasis.

Effectiveness of an acellular synthetic matrix in the treatment of hard-to-heal leg ulcers

Hard-to-heal leg ulcers are a major cause of morbidity in the elderly population. Despite improvements in wound care, some wounds will not heal and they present a significant challenge for patients and health care providers. A multi-centre cohort study was conducted to evaluate the effectiveness and safety of a synthetic, extracellular matrix protein as an adjunct to standard care in the treatment of hard-to-heal venous or mixed leg ulcers. Primary effectiveness criteria were (i) reduction in wound size evaluated by percentage change in wound area and (ii) healing assessed by number of patients healed by end of the 12 week study. Pain reduction was assessed as a secondary effectiveness criteria using VAS. A total of 45 patients completed the study and no difference was observed between cohorts for treatment frequency. Healing was achieved in 35·6% and wound size decreased in 93·3% of patients. Median wound area percentage reduction was 70·8%. Over 50% of patients reported pain on first visit and 87·0% of these reported no pain at the end of the study. Median time to first reporting of no pain was 14 days after treatment initiation. The authors consider the extracellular synthetic matrix protein an effective and safe adjunct to standard care in the treatment of hard-to-heal leg ulcers.

Integrin-functionalized artificial membranes as test platforms for monitoring small integrin ligand binding by surface plasmon-enhanced fluorescence spectroscopy

The design and synthesis of molecularly or supramolecularly defined interfacial architectures have seen in recent years a remarkable growth of interest and scientific research activities for various reasons. On the one hand, it is generally believed that the construction of an interactive interface between the living world of cells, tissue, or whole organisms and the (inorganic or organic) materials world of technical devices such as implants or medical parts requires proper construction and structural (and functional) control of this organism–machine interface. It is still the very beginning of generating a better understanding of what is needed to make an organism tolerate implants, to guarantee bidirectional communication between microelectronic devices and living tissue, or to simply construct interactive biocompatibility of surfaces in general. This exhaustive book lucidly describes the design, synthesis, assembly and characterization, and bio-(medical) applications of interfacial layers on solid substrates with molecularly or supramolecularly controlled architectures. Experts in the field share their contributions that have been developed in recent years.

Binding of small mono- and oligomeric integrin ligands to membrane-embedded integrins monitored by surface plasmon-enhanced fluorescence spectroscopy

We recently developed a binding assay format by incorporating native transmembrane receptors into artificial phospholipid bilayers on biosensor devices for surface plasmon resonance spectroscopy. By extending the method to surface plasmon-enhanced fluorescence spectroscopy (SPFS), sensitive recording of the association of even very small ligands is enabled. Herewith, we monitored binding of synthetic mono- and oligomeric RGD-based peptides and peptidomimetics to integrins alphavbeta3 and alphavbeta5, after having confirmed correct orientation and functionality of membrane-embedded integrins. We evaluated integrin binding of RGD multimers linked together via aminohexanoic acid (Ahx) spacers and showed that the dimer revealed higher binding activity than the tetramer, followed by the RGD monomers. The peptidomimetic was also found to be highly active with a slightly higher selectivity toward alphavbeta3. The different compounds were also evaluated in in vitro cell adhesion tests for their capacity to interfere with alphavbeta3-mediated cell attachment to vitronectin. We hereby demonstrated that the different RGD monomers were similarly effective; the RGD dimer and tetramer showed comparable IC50 values, which were, however, significantly higher than those of the monomers. Best cell detachment from vitronectin was achieved by the peptidomimetic. The novel SPFS-binding assay platform proves to be a suitable, reliable, and sensitive method to monitor the binding capacity of small ligands to native transmembrane receptors, here demonstrated for integrins.

A comparison of patient matched meibum and tear lipidomes

Purpose. To quantify the molecular lipid composition of patient-matched tear and meibum samples and compare tear and meibum lipid molecular profiles. Methods. Lipids were extracted from tears and meibum by bi-phasic methods using 10:3 tertbutyl methyl ether:methanol, washed with aqueous ammonium acetate, and analyzed by chipbased nanoelectrospray ionization tandem mass spectrometry. Targeted precursor ion and neutral loss scans identified individual molecular lipids and quantification was obtained by comparison to internal standards in each lipid class. Results. Two hundred and thirty-six lipid species were identified and quantified from nine lipid classes comprised of cholesterol esters, wax esters, (O-acyl)-x-hydroxy fatty acids, triacylglycerols, phosphatidylcholine, lysophosphatidylcholine, phosphatidylethanolamine, sphingomyelin, and phosphatidylserine. With the exception of phospholipids, lipid molecular profiles were strikingly similar between tears and meibum. Conclusions. Comparisons between tears and meibum indicate that meibum is likely to supply the majority of lipids in the tear film lipid layer. However, the observed higher mole ratio of phospholipid in tears shows that analysis of meibum alone does not provide a complete understanding of the tear film lipid composition.

Epithelial to mesenchymal transition and breast cancer

Epithelial-mesenchymal plasticity in breast carcinoma encompasses the phenotypic spectrum whereby epithelial carcinoma cells within a primary tumor acquire mesenchymal features and re-epithelialize to form a cohesive secondary mass at a metastatic site. Such plasticity has implications in progression of breast carcinoma to metastasis, and will likely influence response to therapy. The transcriptional and epigenetic regulation of molecular and cellular processes that underlie breast cancer and result in characteristic changes in cell behavior can be monitored using an increasing array of marker proteins. Amongst these markers exists the potential for emergent prognostic, predictive and therapeutic targeting.

Children's perspectives on values and rules in Australian early education

In recent years, issues relating to moral and conventional values have been emphasized in educational policies. This study examines young children’s (100 children aged 4–8 years) own understandings of values and rules for how to treat others and participate in school. Eleven classrooms, within seven different elementary schools in Queensland, were visited. Children were interviewed regarding their views about moral and conventional issues, rules and participation in everyday school life. According to the children, ‘doing the right thing’ in school involved both a concern for others’ wellbeing and for the social order in school, including conventions, rules and behaviour connected with discipline. The children’s responsibility seemed, however, to be to adapt to the (school) system, rather than being an active participant in constructing the system.

Contribution of fibroblast and mast cell (afferent) and tumor (efferent) IL-6 effects within the tumor microenvironment

Hyperactive inflammatory responses following cancer initiation have led to cancer being described as a 'wound that never heals'. These inflammatory responses elicit signals via NFκB leading to IL-6 production, and IL-6 in turn has been shown to induce epithelial to mesenchymal transition in breast cancer cells in vitro, implicating a role for this cytokine in cancer cell invasion. We previously have shown that conditioned medium derived from cancer-associated fibroblasts induced an Epithelial to Mesenchymal transition (EMT) in PMC42-LA breast cancer cells and we have now identify IL-6 as present in this medium. We further show that IL-6 is expressed approximately 100 fold higher in a cancer-associated fibroblast line compared to normal fibroblasts. Comparison of mouse-specific (stroma) and human-specific (tumor) IL-6 mRNA expression from MCF-7, MDA MB 468 and MDA MB 231 xenografts also indicated the stroma rather than tumor as a significantly higher source of IL-6 expression. Mast cells (MCs) feature in inflammatory cancer-associated stroma, and activated MCs secrete IL-6. We observed a higher MC index (average number of mast cells per xenograft section/average tumor size) in MDA MB 468 compared to MDA MB 231 xenografts, where all MC were observed to be active (degranulating). This higher MC index correlated with greater mouse-specific IL-6 expression in the MDA MB 468 xenografts, implicating MC as an important source of stromal IL-6. Furthermore, immunohistochemistry on these xenografts for pSTAT3, which lies downstream of the IL-6 receptor indicated frequent correlations between pSTAT3 and mast cell positive cells. Analysis of publically available databases for IL-6 expression in patient tissue revealed higher IL-6 in laser capture microdissected stroma compared to adjacent tissue epithelium from patients with inflammatory breast cancer (IBC) and invasive non-inflammatory breast cancer (non-IBC) and we show that IL-6 expression was significantly higher in Basal versus Luminal molecular/phenotypic groupings of breast cancer cell lines. Finally, we discuss how afferent and efferent IL-6 pathways may participate in a positive feedback cycle to dictate tumor progression.

Bound to the borders: Representing refugees in the Australian space

This project consists of a novel and an exegesis that explore the use of fiction to counter negative hegemonic representations of refugees in Australia. The possibilities of using Australian spaces, including border spaces, to reveal tensions surrounding refugee belonging and to highlight the reconfiguration of border sites in the Australian imaginary, is a particular focus of this work.

Human single-stranded DNA binding protein 1 (hSSB1/NABP2) is required for the stability and repair of stalled replication forks

Aberrant DNA replication is a primary cause of mutations that are associated with pathological disorders including cancer. During DNA metabolism, the primary causes of replication fork stalling include secondary DNA structures, highly transcribed regions and damaged DNA. The restart of stalled replication forks is critical for the timely progression of the cell cycle and ultimately for the maintenance of genomic stability. Our previous work has implicated the single-stranded DNA binding protein, hSSB1/NABP2, in the repair of DNA double-strand breaks via homologous recombination. Here, we demonstrate that hSSB1 relocates to hydroxyurea (HU)-damaged replication forks where it is required for ATR and Chk1 activation and recruitment of Mre11 and Rad51. Consequently, hSSB1-depleted cells fail to repair and restart stalled replication forks. hSSB1 deficiency causes accumulation of DNA strand breaks and results in chromosome aberrations observed in mitosis, ultimately resulting in hSSB1 being required for survival to HU and camptothecin. Overall, our findings demonstrate the importance of hSSB1 in maintaining and repairing DNA replication forks and for overall genomic stability.

Examining the rhetoric : a comparison of how sustainability and young children's participation and agency are framed in Australian and Swedish early childhood education curricula

This article scrutinizes the ways that young children are described and supported as active participants for change within the Australian and Swedish national steering documents for early childhood education. A critical theory lens was applied in combination with document analysis that looked for concepts related to environment and sustainability i.e. environmental, social, economic and political dimension of development, humans place in nature, and environmental stewardship. Concepts concerned with critical thinking, and children as active participants for change were used as specific dimensions of curriculum interpretation. Analyses show that, while both the Australian and Swedish curricula deal with content connected to environmental, social and cognitive dimensions, there is limited or no discussion of the political dimensions of human development, such as children as active citizens with political agency. In other words, children are not recognised as competent beings or agents of change for sustainability within these early childhood curriculum frameworks. Hence, these supposedly contemporary early childhood education documents lack curricular leadership to support children to contribute their voices and actions to civic and public spheres of participation as equal citizens.

Demonstration of regulatory cross-talk between P fimbriae and type 1 fimbriae in uropathogenic Escherichia coli

The majority of Escherichia coli strains isolated from urinary tract infections have the potential to express multiple fimbriae. Two of the most common fimbrial adhesins are type 1 fimbriae and pyelonephritis-associated pili (Pap). Previous research has shown that induced, plasmid-based expression of a Pap regulator, papB, and its close homologues can prevent inversion of the fim switch controlling the expression of type 1 fimbriae. The aim of the present study was to determine if this cross-regulation occurs when PapB is expressed from its native promoter in the chromosome of E. coli K-12 and clinical isolates. The regulation was examined in three ways: (1) mutated alleles of the pap regulatory region, including papB and papI, that maintain the pap promoter in either the off or the on phase were exchanged into the chromosome of both E. coli K-12 and the clinical isolate E. coli CFT073, and the effect on type 1 fimbrial expression was measured; (2) type 1 fimbrial expression was determined using a novel fimS : : gfp+ reporter system in mutants of the clinical isolate E. coli 536 in which combinations of complete fimbrial clusters had been deleted; (3) type 1 fimbrial expression was determined in a range of clinical isolates and compared with both the number of P clusters and their expression. All three approaches demonstrated that P expression represses type 1 fimbrial expression. Using a number of novel genetic approaches, this work extends the initial finding that PapB inhibits FimB recombination to the impact of this regulation in clinical isolates.

Effects of supervision on tax compliance : evidence from a field experiment in Austria

We conduct a field experiment on tax compliance, focusing on newly founded firms. As a novelty the effect of tax authorities’ supervision on timely tax payments is examined. Interestingly, results show no positive overall effect of close supervision on tax compliance.