4582 research outputs found
Sort by
Development of a low cost flight simulator to enhance students' learning of technical and non-technical flight skills
No full textPrevious research by the author has shown that the use of a simulator for preliminary technical flight skills training has led to improved student performance in flight training. The author has also espoused the use of a simulator for the training of non-technical flight skills, in addition to the training of technical flight skills. The unique property of this flight simulator is the ability to view and export flight data from the device. This is important because it will enable analysis of pilot, or student pilot, to determine whether the flight is safe or unsafe, or student performance is satisfactory or unsatisfactory. The ability to access flight performance data will increase the effectiveness of students’ experiential learning and will greatly assist current research projects under way in the AERO Lab. In this paper, the author describes this relatively low cost flight training device.
Effect of ionic strength and index cation on the sorption of phenanthrene
No full textSorption characteristics of phenanthrene were studied in batch equilibrium experiments with 32 Australian soils that varied widely in physicochemical properties. Sorption of phenanthrene varied widely among the soils and was generally nonlinear, with the nonlinearity index (n) of the Freundlich isotherm varying from 0.62 to 1.01. Simple regression analyses revealed that total organic carbon (TOC) accounts for about 68 % of the variation in the partition coefficient (K′ f ) for sorption among the soils at an equilibrium concentration (C e ) of 0.05 mg/L. The organic carbon normalized distribution coefficient (K OC ), varied considerably between soils with >70 % of the variance of logK OC being accounted for by logTOC, clay and log dissolved organic carbon (DOC). These results show that the phenanthrene C e is influenced by both TOC as well as the DOC in soil suspensions. The effects of ionic strength (IS) and index cation were investigated using four contrasting soils. Results show that with an increase in IS from 0.03 to 0.15 M sorption of phenanthrene generally increased in CaCl2 background solutions, whereas the effect was less significant and variable in NaCl background solutions. Sorption of phenanthrene was slightly higher at low IS (0.03 M) with Na+ as index cation compared with that of Ca2+, whereas an opposite trend was observed at higher IS (0.15 M). For two soils high in TOC, the flocculation of endogenous DOC in the presence of Ca2+ reduced the influence of background electrolyte and resulted in a more linear sorption isotherm as well as higher sorption capacity. This trend was more significant with Ca2+ relative to Na+.
Quantitative determination of metal and metalloid spatial distribution in hydrated and fresh roots of cowpea using synchrotron-based X-ray fluorescence microscopy
No full textMany metals and metalloids, jointly termed metal(loid)s, are toxic to plants even at low levels. This has limited the study of their uptake, distribution, and modes of action in plant roots grown at physiologically relevant concentrations. Synchrotron-based X-ray fluorescence microscopy was used to examine metal(loid)s in hydrated cowpea (Vigna unguiculata L.) roots exposed to Zn(II), Ni(II), Mn(II), Cu(II), Hg(II), Se(IV), Se(VI), As(III), or As(V). Development of a mathematical model enabled in situ quantitative determination of their distribution in root tissues. The binding strength of metals influenced the extent of their movement through the root cylinder, which influenced the toxic effects exerted—metals (e.g. Cu, Hg) that bind more strongly to hard ligands had high concentrations in the rhizodermis and caused this tissue to rupture, while other metals (e.g. Ni, Zn) moved further into the root cylinder and did not cause ruptures. When longitudinal distributions were examined, the highest Se concentration in roots exposed to Se(VI) was in the more proximal root tissues, suggesting that Se(VI) is readily loaded into the stele. This contrasted with other metal(loid)s (e.g. Mn, As), which accumulated in the apex. These differences in metal(loid) spatial distribution provide valuable quantitative data on metal(loid) physiology, including uptake, transport, and toxicity in plant roots.
Development of a low-tech, low-cost alternative to aquaponics, integrating agriculture and aquaculture
No full textResearch proposal (PhD)--University of South Australia, 2013.
Compressional intracontinental orogens : ancient and modern perspectives
No full textCompressional intracontinental orogens are major zones of crustal thickening produced at large distances from active plate boundaries. Consequently, any account of their initiation and subsequent evolution must be framed outside conventional plate tectonics theory, which can only explain the proximal effects of convergent plate-margin interactions. This review considers a range of hypotheses regarding the origins and transmission of compressive stresses in intraplate settings. Both plate-boundary and intraplate stress sources are investigated as potential driving forces, and their relationship to rheological models of the lithosphere is addressed. The controls on strain localisation are then evaluated, focusing on the response of the lithosphere to the weakening effects of structural, thermal and fluid processes. With reference to the characteristic features of intracontinental orogens in central Asia (the Tien Shan) and central Australia (the Petermann and Alice Springs Orogens), it is argued that their formation is largely driven by in-plane stresses generated at plate boundaries, with the lithosphere acting as an effective stress guide. This implies a strong lithospheric mantle rheology, in order to account for far-field stress propagation through the discontinuous upper crust and to enable the support of thick uplifted crustal wedges. Alternative models of intraplate stress generation, primarily involving mantle downwelling, are rejected on the grounds that their predicted temporal and spatial scales for orogenesis are inconsistent with the observed records of deformation. Finally, inherited mechanical weaknesses, thick sedimentary blanketing over a strongly heat-producing crust, and pervasive reaction softening of deep fault networks are identified as important and interrelated controls on the ability of the lithosphere to accommodate rather than transmit stress. These effects ultimately produce orogenic zones with architectural features and evoluti
The GM-CSF receptor family : mechanism of activation and implications for disease
No full textGranulocyte-macrophage colony-stimulating factor (GM-CSF) is a pluripotent cytokine produced by many cells in the body, which regulates normal and malignant hemopoiesis as well as innate and adaptive immunity. GM-CSF assembles and activates its heterodimeric receptor complex on the surface of myeloid cells, initiating multiple signaling pathways that control key functions such as cell survival, cell proliferation, and functional activation. Understanding the molecular composition of these pathways, the interaction of the various components as well as the kinetics and dose-dependent mechanics of receptor activation provides valuable insights into the function of GM-CSF as well as the related cytokines, interleukin-3 and interleukin-5. This knowledge provides opportunities for the development of new therapies to block the action of these cytokines in hematological malignancy and chronic inflammation.
The global challenge for accounting education
No full textAccounting and education are both global phenomena, and there is thus an argument that accounting education should be consistent and comparable across the globe. However, accounting, and accounting education are all socially constructed and globally they have been influenced by their historical, social, economic, political and cultural contexts. This has resulted in many fragmented, heterogeneous communities of practice and many diverse audiences or stakeholders with their own interests and legitimation strategies. There is thus a problem for accounting education to be defined, and to coalesce to one world model that fits the needs of all nations. However, global accounting education can adopt similar learning objectives by using constructivist, experiential and situated learning approaches that are embedded in to the learning programme. The International Education Standards (IES) of the IAESB should be revised to embed these three learning approaches, and IFAC and the IAESB should adopt various strategies to gain pragmatic legitimacy for its education standards.
Nutlin-3a efficacy in sarcoma predicted by transcriptomic and epigenetic profiling
No full textNutlin-3a is a small molecule antagonist of p53/MDM2 that is being explored as a treatment for sarcoma. In this study, we examined the molecular mechanisms underlying the sensitivity of sarcomas to Nutlin-3a. In an ex vivo tissue explant system, we found that TP53 pathway alterations (TP53 status, MDM2/MDM4 genomic amplification/mRNA overexpression, MDM2 SNP309, and TP53 SNP72) didn't confer apoptotic or cytostatic responses in sarcoma tissue biopsies (n=24). Unexpectedly, MDM2 status didn't predict Nutlin-3a sensitivity. RNA sequencing revealed that the global transcriptomic profiles of these sarcomas provided a more robust prediction of apoptotic responses to Nutlin-3a. Expression profiling revealed a subset of TP53 target genes which were transactivated specifically in sarcomas that were highly sensitive to Nutlin-3a. Of these target genes, the GADD45A promoter region was shown to be hypermethylated in 82% of wild-type TP53 sarcomas that didn't respond to Nutlin-3a, thereby providing mechanistic insight into the innate ability of sarcomas to resist apoptotic death following Nutlin-3a treatment. Collectively, our findings argue that the existing benchmark biomarker for MDM2 antagonist efficacy (MDM2 amplification) should not be used to predict outcome, but rather global gene expression profiles and epigenetic status of sarcomas dictate their sensitivity to p53/MDM2 antagonists.
A comparative analysis of dam safety assurance laws : what are 'appropriate' legislative arrangements for jurisdictions with hazardous private dams?
No full textA number of horrific failures of both public and privately owned dams in recent decades has triggered serious concern over the safety of dams throughout the world. However, in Australia, although much Government attention is being devoted to the medium- to large-scale dams, minimal attention is being paid to the serious potential cumulative, catchment-wide problems associated with smaller private dams. The paper determines how to consider addressing hazardous private dam safety issues generally through a comparative analysis of international dam safety policy/law systems. The analysis has identified elements of best and minimum practice that can and do exist successfully to provide deserved assurance to the community of the proper safety management of hazardous private dams at both the individual and cumulative, catchment-wide levels. These elements provide benchmarks that enable ‘appropriate’ legislative arrangements to be determined for different jurisdictional circumstances as illustrated with an Australian policy-deficient case study.