101 research outputs found

    The 'Southern Gateway' between Australia and Antarctica : A Proposal for ODP Palaeoclimatic, Palaeoceanographic and Transform Margin Drilling

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    Dealing with Climate Change: Paleoclimate research in Australia

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    Palaeoclimate research relevant to marine systems in Australia includes the collection and analysis of: (a) shallow-water and deep-sea corals, which provide highresolution archives, (b) deep-sea sediment and ice cores, which span longer time scales, and (c) palaeoclimate modelling, which gives us insights into mechanisms, dynamics and thresholds underlying past climate states. Palaeoclimate research in Australia is mature and well recognised internationally. To further advance Australian palaeoclimate research, we must address major challenges that include insufficient research vessel access, insufficient targeted research funding, as well as the lack of a well funded national centre to coordinate research efforts (e.g. academic institution or ARC Centre of Excellence for Palaeoclimate Research)

    The planform of epeirogeny: vertical motions of Australia during the Cretaceous

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    Estimates of dynamic motion of Australia since the end of the Jurassic have been made by modeling marine flooding and comparing it with palaeogeographical reconstructions of marine inundation. First, sediment isopachs were back stripped from present-day topography. Dynamic motion was determined by the displacement needed to approximate observed flooding when allowance is made for changes in eustatic sea-level. The reconstructed inundation patterns suggest that during the Cretaceous, Australia remained a relatively stable platform, and flooding in the eastern interior during the Early Cretaceous was primarily the result of the regional tectonic motion. Vertical motion during the Cretaceous was much smaller than the movement since the end of the Cretaceous. Subsidence and marine flooding in the Eromanga and Surat Basins, and the subsequent 500 m of uplift of the eastern portion of the basin, may have been driven by changes in plate dynamics during the Mesozoic. Convergence along the north-east edge of Australia between 200 and 100 Ma coincides with platform sedimentation and subsidence within the Eromanga and Surat Basins. A major shift in the position of subduction at 140 Ma was coeval with the marine incursion into the Eromanga. When subduction ended at 95 Ma, marine inundation of the Eromanga also ended. Subsidence and uplift of the eastern interior is consistent with dynamic models of subduction in which subsidence is generated when the dip angle of the slab decreases and uplift is generated when subduction terminates (i.e. the dynamic load vanishes). Since the end of the Cretaceous, Australia has uniformly subsided by about 250 m with little apparent tilting. This vertical subsidence may have resulted from the northward migration of the continent from a dynamic topography high and geoid low toward lower dynamic topography and a higher geoid.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71983/1/j.1365-2117.1994.tb00076.x.pd

    New challenges for BRCA testing:a view from the diagnostic laboratory

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    Increased demand for BRCA testing is placing pressures on diagnostic laboratories to raise their mutation screening capacity and handle the challenges associated with classifying BRCA sequence variants for clinical significance, for example interpretation of pathogenic mutations or variants of unknown significance, accurate determination of large genomic rearrangements and detection of somatic mutations in DNA extracted from formalin-fixed, paraffin-embedded tumour samples. Many diagnostic laboratories are adopting next-generation sequencing (NGS) technology to increase their screening capacity and reduce processing time and unit costs. However, migration to NGS introduces complexities arising from choice of components of the BRCA testing workflow, such as NGS platform, enrichment method and bioinformatics analysis process. An efficient, cost-effective accurate mutation detection strategy and a standardised, systematic approach to the reporting of BRCA test results is imperative for diagnostic laboratories. This review covers the challenges of BRCA testing from the perspective of a diagnostics laboratory

    Divergent Immune Responses in Behaviorally-Inhibited vs. Non-Inhibited Male Rats

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    Stable behavioral traits (temperament, personality) often predict health outcomes. Temperament-specific differences in immune function could explain temperament-specific health outcomes, however, we have limited information on whether immune function varies by personality. In the present study, we examined the relationship between a basic behavioral trait (behavioral-inhibition vs. non-inhibition) and two immune responses (innate inflammation and delayed-type hypersensitivity, DTH) in a rodent model. In humans, behavioral inhibition (fearful temperament) is associated with altered stress physiology and allergies. In laboratory rats, the trait is associated with elevated glucocorticoid production. We hypothesized that behavioral inhibition is associated with glucocorticoid resistance and dampened T-helper 1 cell responses often associated with chronic stress and allergies. Further, this immune profile would predict poorly-regulated innate inflammation and dampened DTH. In male Sprague-Dawley rats, we quantified consistent behavioral phenotypes by measuring latency to contact two kinds of novelty (object vs. social), then measured lipopolysaccharide(LPS)-induced innate inflammation or keyhole limpet hemocyanin(KLH)-induced DTH. Behaviorally-inhibited rats had heightened glucocorticoid and interleukin-6 responses to a low/moderate dose of LPS and reduced DTH swelling to KLH re-exposure compared to non-inhibited rats. These results suggest that behavioral inhibition is associated with a glucocorticoid resistant state with poorly regulated innate inflammation and dampened cell-mediated immune responses. This immune profile may be associated with exaggerated T-helper 2 responses, which could set the stage for an allergic/asthmatic/atopic predisposition in inhibited individuals. Human and animal models of temperament-specific immune responses represent an area for further exploration of mechanisms involved in individual differences in health

    Quantitative analysis of a footwall‐scarp degradation complex and syn‐rift stratigraphic architecture, Exmouth Plateau, NW Shelf, offshore Australia

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    Interactions between footwall‐, hangingwall‐ and axial‐derived depositional systems make syn‐rift stratigraphic architecture difficult to predict, and preservation of net‐erosional source landscapes is limited. Distinguishing between deposits derived from fault‐scarp degradation (consequent systems) and those derived from long‐lived catchments beyond the fault block crest (antecedent systems) is also challenging, but important for hydrocarbon reservoir prospecting. We undertake geometric and volumetric analysis of a fault‐scarp degradation complex and adjacent hangingwall‐fill associated with the Thebe‐2 fault block on the Exmouth Plateau, NW Shelf, offshore Australia, using high resolution 3D seismic data. Vertical and headward erosion of the complex and fault throw are measured. Seismic‐stratigraphic and seismic facies mapping allow us to constrain the spatial and architectural variability of depositional systems in the hangingwall. Footwall‐derived systems interacted with hangingwall‐ and axial‐derived systems, through diversion around topography, interfingering or successive onlap. We calculate the volume of footwall‐sourced hangingwall fans (VHW) for nine quadrants along the fault block, and compare this to the volume of material eroded from the immediately up‐dip fault‐scarp (VFW). This analysis highlights areas of sediment bypass (VFW > VHW) and areas fed by sediment sources beyond the degraded fault scarp (VHW > VFW). Exposure of the border fault footwall and adjacent fault terraces produced small catchments located beyond the fault block crest that fed the hangingwall basin. One source persisted throughout the main syn‐rift episode, and its location coincided with: (a) an intra‐basin topographic high; (b) a local fault throw minimum; (c) increased vertical and headward erosion within the fault‐scarp degradation complex; and (d) sustained clinoform development in the immediate hangingwall. Our novel quantitative volumetric approach to identify through‐going sediment input points could be applied to other rift basin‐fills. We highlight implications for hydrocarbon exploration and emphasize the need to incorporate interaction of multiple sediment sources and their resultant architecture in tectono‐stratigraphic models for rift basins
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