The Use, Evolution and Lessons Learnt of Deployable Static Solar Array Mechanisms

This paper focuses on the mechanisms incorporated into SSTL's static deployable arrays; namely the sprung-hinges and hold down and release mechanism (HDRM). Combined, the HDRM and hinges form the hold down release system (HDRS). The deployable static solar array HDRS has been successfully used on several missions, first launched upon the DMC-CFESAT spacecraft in 2007 for a U.S. customer (Figure 1), and later used on DMC-UK2 and EXACTVIEW-1 launched in 2009 and 2012, respectively. The simple, robust and low-cost solution HDRS has been evident in allowing missions to satisfy an ever increasing power demand, allowing the solar arrays to increase in size and have a preferable sun angle for increased cell efficiency. The system is now being employed on the first mission out of SSTL's U.S. office (SST-US) on the Orbital Test Bed platform. This paper shall cover details of the original design and development program, problems incurred on latter missions, and evolution of the HDRS for the present Orbital Test Bed mission. Both the original development and recent evolutions have taken place in rapid timescales, to satisfy the high-turnaround of SSTL missions

Heterosynaptic plasticity in pyramidal neurons of the hippocampus

Homeostatic synaptic plasticity (HSP) is an adjustment of synaptic strength which compensates for chronically altered activity levels in a neuron’s inputs. It is proposed that HSP allows the neuron to retain its ability to discriminate between different inputs in a changing environment. HSP has been demonstrated at several levels: the network, the individual neuron, and the synapse. Synapse-specific HSP involves a paradox: if intense transmission strengthens a synapse, HSP will act in a compensatory direction to weaken the same synapse, effectively erasing the memory trace laid down by the initial stimulus. As a solution to this paradox, it has been proposed that the synapse’s homeostatic “tariff” is actually shared with its neighbouring synapses, thus maintaining the strength of the synapse relative to its neighbours. My project aimed to test this hypothesis directly by strengthening a single synapse with a glutamate uncaging “tetanus”, and then estimating changes in the strength of neighbouring synapses by acquiring high-magnification confocal images of the corresponding spines and measuring their head diameters at various time points. The results reported in this thesis confirm the hypothesis – a fraction of spines within 20 to 30 μm of the strengthened spine undergo substantial shrinkage. This heterosynaptic effect is long- lasting (it is still evident 60 minutes after uncaging), and large spines are more likely to shrink than small ones. This thesis also reports followup experiments in which possible mechanisms were explored. Rapid confocal scanning of calcium indicator dye was used to detect possible calcium signals flowing from the uncaging target along the dendrite into neighbouring spines. However, KN62 was found to abolish the heterosynaptic shrinkage effect, indicating that CaMK2 activation is required, which suggests that calcium may not be the signal for heterosynaptic shrinkage

Australian coal mining: Estimating technical change and resource rents in a translog cost function

This paper estimates a translog cost function for the Australian coal industry from 1968/69 to 2004/05. We use a variable measuring the shift to open-pit mining to capture the impact of embodied technical change, while using a time trend to capture the impact of other technical change and changing resource rents. The cost function is estimated with Zellner's SUR procedure. The shift to open-cut mining is shown to be important in lowering cost during the 1970s and 1980s, but more recently cost reduction is captured by the time trend

A compact light-sheet microscope for the study of the mammalian central nervous system

Investigation of the transient processes integral to neuronal function demands rapid and high-resolution imaging techniques over a large field of view, which cannot be achieved with conventional scanning microscopes. Here we describe a compact light sheet fluorescence microscope, featuring a 45° inverted geometry and an integrated photolysis laser, that is optimized for applications in neuroscience, in particular fast imaging of sub-neuronal structures in mammalian brain slices. We demonstrate the utility of this design for three-dimensional morphological reconstruction, activation of a single synapse with localized photolysis, and fast imaging of neuronal Ca2+ signalling across a large field of view. The developed system opens up a host of novel applications for the neuroscience community

STAR: A consensus for skin tear classification.

Until now the Payne-Martin Classification System for Skin Tears has been the only skin tear classification system reported in the literature. Considering that the development of this taxonomy began over twenty years ago, it is rather puzzling that it has been poorly utilised in Australia. especially in light of the fact that skin tears are perceived to be common wounds amongst frail older or disabled persons 1, 2, 3 and their prevalence can be expected to escalate in line with our ageing population. Stage one of the Skin Tear Audit Research (STAR) study aimed to gain a consensus from Australian nurse experts in wound management on a classification system for skin tears and to test the reliability of the resulting classification system. This paper reports on the processes undertaken to achieve a consensus, the STAR Skin Tear Classification System that resulted, and the reliability testingthat it underwent

Raman micro-spectroscopy for accurate identification of primary human bronchial epithelial cells.

Live cell Raman micro-spectroscopy is emerging as a promising bioanalytical technique for label-free discrimination of a range of different cell types (e.g. cancer cells and fibroblasts) and behaviors (e.g. apoptosis). The aim of this study was to determine whether confocal Raman micro-spectroscopy shows sufficient sensitivity and specificity for identification of primary human bronchial epithelial cells (HBECs) to be used for live cell biological studies in vitro. We first compared cell preparation substrates and media, considering their influence on lung cell proliferation and Raman spectra, as well as methods for data acquisition, using different wavelengths (488 nm, 785 nm) and scan protocols (line, area). Evaluating these parameters using human lung cancer (A549) and fibroblast (MRC5) cell lines confirmed that line-scan data acquisition at 785 nm using complete cell media on a quartz substrate gave optimal performance. We then applied our protocol to acquisition of data from primary human bronchial epithelial cells (HBEC) derived from three independent sources, revealing an average sensitivity for different cell types of 96.3% and specificity of 95.2%. These results suggest that Raman micro-spectroscopy is suitable for delineating primary HBEC cell cultures, which in future could be used for identifying different lung cell types within co-cultures and studying the process of early carcinogenesis in lung cell culture

Breaking the Smallsat Barriers to Sub-50cm Imaging

New cutting-edge imaging sensors can now reduce instrument size and mass, leading to mission cost savings, and bring sub-50cm imaging capability into the realm of small satellites. Whilst aperture is essential to achieving resolution, half-pixel shifted sensor architectures decouple achievable Ground Sampling Distance (GSD) from the native ground projected pixel. This facilitates the deployment of Very High Resolution (VHR) small satellite constellations featuring improved Signal-to-Noise performance and increased area collection rates compared to push-frame systems. A fundamental limitation to the theoretical performance of an optical system is imposed by its aperture diameter; hence, for a given aperture, the aim is to maximize the information content resolved up to this limit. This is achieved by minimizing losses caused by aberrations in the optical system and enhancing platform stability on-orbit. Further information is lost due to aliasing at higher spatial frequencies; however, the recovery of such information is unlocked through the novel sensor technology and processing techniques proposed. Funded under the European Space Agency (ESA) “Investing in Industrial Innovation” (InCubed) program, this paper reports on the build and verification campaign of a sub-50cm capable instrument Proto-Flight Model (PFM), the beneficial properties of half-pixel offset sensors, and the platform supporting such a payload

Standard set of health outcome measures for older persons

Background: The International Consortium for Health Outcomes Measurement (ICHOM) was founded in 2012 to propose consensus-based measurement tools and documentation for different conditions and populations.This article describes how the ICHOM Older Person Working Group followed a consensus-driven modified Delphi technique to develop multiple global outcome measures in older persons. The standard set of outcome measures developed by this group will support the ability of healthcare systems to improve their care pathways and quality of care. An additional benefit will be the opportunity to compare variations in outcomes which encourages and supports learning between different health care systems that drives quality improvement. These outcome measures were not developed for use in research. They are aimed at non researchers in healthcare provision and those who pay for these services. Methods: A modified Delphi technique utilising a value based healthcare framework was applied by an international panel to arrive at consensus decisions.To inform the panel meetings, information was sought from literature reviews, longitudinal ageing surveys and a focus group. Results: The outcome measures developed and recommended were participation in decision making, autonomy and control, mood and emotional health, loneliness and isolation, pain, activities of daily living, frailty, time spent in hospital, overall survival, carer burden, polypharmacy, falls and place of death mapped to a three tier value based healthcare framework. Conclusions: The first global health standard set of outcome measures in older persons has been developed to enable health care systems improve the quality of care provided to older persons

SLUG transcription factor : a pro-survival and prognostic factor in gastrointestinal stromal tumour

Background: The SLUG transcription factor has been linked with the KIT signalling pathway that is important for gastrointestinal stromal tumour (GIST) tumourigenesis. Its clinical significance in GIST is unknown. Methods: Influence of SLUG expression on cell proliferation and viability were investigated in GIST48 and GIST882 cell lines. The association between tumour SLUG expression in immunohistochemistry and recurrence-free survival (RFS) was studied in two clinical GIST series, one with 187 patients treated with surgery alone, and another one with 313 patients treated with surgery and adjuvant imatinib. Results: SLUG downregulation inhibited cell proliferation, induced cell death in both cell lines, and sensitised GIST882 cells to lower imatinib concentrations. SLUG was expressed in 125 (25.0%) of the 500 clinical GISTs evaluated, and expression was associated with several factors linked with unfavourable prognosis. SLUG expression was associated with unfavourable RFS both when patients were treated with surgery alone (HR = 3.40, 95% CI = 1.67-6.89, P = 0.001) and when treated with surgery plus adjuvant imatinib (HR = 1.83, 95% CI = 1.29-2.60, P = 0.001). Conclusions: GIST patients with high tumour SLUG expression have unfavourable RFS. SLUG may mediate pro-survival signalling in GISTs.Peer reviewe