1,172 research outputs found

    Microthruster Experimental Analysis

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    The purpose of this study was to design an experimental apparatus that could accurately test and measure the thrust efficiency of conical shaped microthrusters with varying divergence half angles. The experimental apparatus measured the thrust of micronozzles for various feed pressures in vacuum (to duplicate in space operation) as well as ambient. Calibration experiments confirmed the force measurement accuracy of the setup while gas thrust experiments were used to help determine the most efficient divergence half angle. Thrust results were compared to findings from two separate scientific studies that sought to optimize microthruster nozzles using CFD software

    The first reintroduction of the western barred bandicoot (Perameles bougainville) to mainland Australia.

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    Almost half of the world's mammal extinctions in the last two hundred years have occurred in Australia (Short and Smith 1994). The western barred bandicoot Perameles bougainville is one of a suite of species that is currently threatened with extinction, surviving only on two islands in Shark Bay, Western Australia. Reintroduction has been used as a tool in conservation biology to assist in the recovery of threatened species, such as the western barred bandicoot. The aims of this project were to 1) successfully reintroduce and establish a free-ranging mainland population of the western barred bandicoot at Heirisson Prong, Shark Bay, 2) contribute information on the biology of the species, its interactions with introduced species, and its likelihood of persistence as a reintroduced population in the longer-term, and 3) to provide recommendations to assist future reintroductions of the species. The first reintroduction of the western barred bandicoot from surviving remnant island populations to the mainland, some 60 years after its apparent mainland extinction, was from Dorre Island to Heirisson Prong in 1995. Animals were translocated initially to a predator-free refuge on Heirisson Prong, and then subsequently released to the 12 km2 peninsula where introduced predators (foxes Vulpes vulpes and feral cats Felis catus) had been controlled, but European rabbits Oryctolagus cuniculus had not. Despite a small founder number and high mortality of free-range bandicoots in the presence of a low-density feral cat population, the bandicoot population successfully established. The reintroduced population of western barred bandicoots provided an opportunity to study the biology of the species, and to compare it with the remnant island populations and other species of Australian bandicoot. Many population parameters were similar between the island and mainland western barred bandicoot populations, as well as between the western barred bandicoot and other bandicoot species, suggesting that the habitat at the reintroduction site is suitable for long-term persistence of the population. However, there were some notable differences. The western barred bandicoot is the smallest extant species of bandicoot, with fewer young per litter than recorded for other bandicoot species, adult sex ratios were closer to parity, animals reached sexual maturity later, and it is the only species of bandicoot where females are larger than males. Home range size is larger also than recorded for other species. Some of these differences may be explained in part by trade-offs between island dwarfism, lactational pressures, and nest defence. The nesting biology of the western barred bandicoot was studied at Heirisson Prong, including during periods of high and low densities of rabbits. Individuals of the species constructed and utilised nests in a similar fashion to other species of Australian bandicoot, nesting amongst litter underneath shrubs. The western barred bandicoot appeared to favour particular shrub species, especially when vegetation condition was poor due to rabbit damage, but displayed flexibility in being able to construct nests under a variety of shrub species where at least some surface litter was present. Grasses were used in nest construction only when rabbit density was low. Nests appear important for protection against temperature extremes and diurnal predators. Vegetation exclosures around three of the shrub species most commonly used by the western barred bandicoot for nest sites (Acacia ligulata, A. tetragonophylla and Melaleuca cardiophylla) were used to examine the impact of rabbits on vegetation on Heirisson Prong. A high-density rabbit population over the summer of 1997/98 caused in a decrease in canopy cover and the death of mature A. ligulata. Subsequent rainfall and low-density rabbit populations allowed A. tetragonophylla shrubs to recover their former structure, and M. cardiophylla to recover, but not to the same degree. The flexibility of western barred bandicoots in use of nest materials and their omnivorous diet may enable the species to survive in the face of habitat modification by rabbits. Population viability analysis was used to examine future options for the recovery of the endangered western barred bandicoot. Biological data from the Dorre Island and Heirisson Prong populations were input to the computer simulation program VORTEX. The western barred bandicoot populations were modelled under a variety of scenarios to examine the possible effects of changes in carrying capacity, founder population size, inbreeding depression, and the occurrence of drought and cat predation as catastrophes, on the probability of population extinction. This analysis highlighted the need for eradication of feral cats, above all other management actions. Cat predation was particularly potent when it acted through high loss of juveniles, as well as adult bandicoots. Predator control is considered critical for the long-term persistence of reintroduced populations of the western barred bandicoot. This study documents the first reintroduction of the endangered western barred bandicoot to mainland Australia. The population had been extant for four years at the completion of data collection for this thesis, in late 1999 and for over eight years at the finalisation of this thesis in July 2004. The knowledge gained from the reintroduction was used to discuss management recommendations and future options for the recovery of the species. The primary concern for reintroductions of this, and other species of bandicoots, remains the control of introduced predators. For long-term persistence of small, isolated populations, such as those of the western barred bandicoot at Heirisson Prong and the Arid Recovery Project at Roxby Downs in South Australia, and the eastern barred bandicoot Perameles gunnii at a range of sites in Victoria, the complete eradication of introduced predators is essential

    Glycan heterogeneity on gold nanoparticles increases lectin discrimination capacity in label-free multiplexed bioassays

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    The development of new analytical tools as point-of-care biosensors is crucial to combat the spread of infectious diseases, especially in the context of drug-resistant organisms, or to detect biological warfare agents. Glycan/lectin interactions drive a wide range of recognition and signal transduction processes within nature and are often the first site of adhesion/recognition during infection making them appealing targets for biosensors. Glycosylated gold nanoparticles have been developed that change colour from red to blue upon interaction with carbohydrate-binding proteins and may find use as biosensors, but are limited by the inherent promiscuity of some of these interactions. Here we mimic the natural heterogeneity of cell-surface glycans by displaying mixed monolayers of glycans on the surface of gold nanoparticles. These are then used in a multiplexed, label-free bioassay to create ‘barcodes’ which describe the lectin based on its binding profile. The increased information content encoded by using complex mixtures of a few sugars, rather than increased numbers of different sugars makes this approach both scalable and accessible. These nanoparticles show increased lectin identification power at a range of lectin concentrations, relative to single-channel sensors. It was also found that some information about the concentration of the lectins can be extracted, all from just a simple colour change, taking this technology closer to being a realistic biosensor

    An innovative approach to improve ear, nose and throat surgical access for remote living Cape York Indigenous children

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    Introduction: On a background of high rates of severe otitis media (OM) with associated hearing loss, children from the Torres Strait and Cape York region requiring ear, nose and throat (ENT) surgery, faced waiting times exceeding three years. After numerous clinical safety incidents were raised, indicating a failure of the current system to deliver appropriate care, the governing Hospital and Health service opted to deliver surgical care through an alternate process. ENT surgeries were performed on 16 consented children from two remote locations via the private health care system, funded by a health provider partnership. Methods: We examined the collaboration processes alongside clinical findings from this ENT surgery. Collated patient data, included patient demographics, clinical and audiometry presentation features were reviewed and compared pre and post-operatively. Cost savings associated with the use of TeleHealth post-operatively were briefly examined. Results: Surgeries were successfully completed in all 16 children. The reported mean waitlist time for ENT surgery was 1.2 years. Pre-surgery pure-tone average hearing thresholds were reported at left: 30.9 dB, right: 38.2 dB. The majority of presentations were for bilateral OM with Effusion (69%). Post-surgical follow up indicated successful clinical outcomes in 80% of patients and successful hearing outcomes in 88% of patients. Mean difference pure-tone average hearing thresholds, left: 8.4 dB and right: 11.2 dB. Furthermore, the majority of patients reported improved hearing and breathing. The use of TeleHealth for post-operative review enabled a minimum cost saving of AUD$21,664 for these 16 children. Overall, a high level of staffing resources was required to successfully coordinate this intense surgical activity. Conclusion: This innovative approach to a health system crisis enabled successful ENT surgical and hearing outcomes in 16 children, whose waitlisted time grossly exceeded state health recommendations. Using private health facilities funded by a health partnership, while unlikely to be a suitable model of care for routine service delivery; may be applied as an adjunct service model when blockages and delays lead to sub-standard service provision. This approach may be applicable to other health care facilities when facing extended elective surgery wait times in ENT or other specialty areas

    The Response of Hemostatic Marker Levels to Activated Factor VII in a Neonate following Cardiopulmonary Bypass

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    The primary function of recombinant activated factor VII (rFVIIa) is to increase thrombin formation which leads to increased fibrin and less “bleeding.” As a result, most of literature utilizes “bleeding” as the outcome measure with respect to rFVIIa. However, we report the actual effect of rFVIIa on changes in hemostatic markers such as prothrombin activation peptide F1.2, thrombin antithrombin complex (TAT), D-dimer, tissue plasminogen activator (tPA), and plasminogen activator inhibitor (PAI) in a neonate after cardiopulmonary bypass. A single dose of rFVIIa caused a 5.5-fold increase in F1.2, 3.5-fold increase in TAT, and a small increase in d-dimer compared to only a 1.5-fold increase, no increase, and a decrease, respectively, in two neonates undergoing the same procedure having not received rFVIIa. The patterns of change for tPA and PAI were similar

    Developing a Faculty Learning Community to Support Writing Across Different STEM Disciplines

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    Writing to learn is one of the very important pedagogical strategies in a variety of disciplines. This concept is not specifically addressed in the majority of engineering courses. Hence, university initiatives such as the Quality Enhancement Plan (QEP), emerging out of accreditation and institutional assessments, are focusing on infusing scholarship from other disciplines (in this case English) for the purpose of student learning improvement. Engineering and Science programs do include various courses in English Composition as the part of the curriculum; however, writing is not embedded in all discipline-specific courses at the upper-division level. The program outlined here focuses on the exploration of possible methods for engineering and science faculty to embed more writing assignments in their STEM courses so that undergraduate students can adequately transfer what they learned from English courses and apply it in their specific discipline once they attain higher proficiency (at the junior and senior level). The project presented in this paper included the creation of a Faculty Learning Community (FLC) composed of English, Engineering, and Science scholars, with the goal of developing writing assignments that enhance student learning while also building off of writing concepts students learn in introductory writing courses. This paper evaluates the effect of the FLC on student learning and on faculty professional development

    Interactions between interfaces dictate stimuli-responsive emulsion behaviour

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    Stimuli-responsive emulsions offer a dual advantage, combining long-term storage with controlled release triggered by external cues such as pH or temperature changes. This study establishes that thermo-responsive emulsion behaviour is primarily determined by interactions between, rather than within, interfaces. Consequently, the stability of these emulsions is intricately tied to the nature of the stabilizing microgel particles - whether they are more polymeric or colloidal, and the morphology they assume at the liquid interface. The colloidal properties of the microgels provide the foundation for the long-term stability of Pickering emulsions. However, limited deformability can lead to non-responsive emulsions. Conversely, the polymeric properties of the microgels enable them to spread and flatten at the liquid interface, enabling stimuli-responsive behaviour. Furthermore, microgels shared between two emulsion droplets in flocculated emulsions facilitate stimuli-responsiveness, regardless of their internal architecture. This underscores the pivotal role of microgel morphology and the forces they exert on liquid interfaces in the control and design of stimuli-responsive emulsions and interfaces.ISSN:2041-172

    A mixed methods PAR study investigating social capital as a resource for Black and other racially minoritised communities in the UK:A study protocol

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    Understanding how different Black and other racially minoritised communities thrive is an emerging priority area in mental health promotion. Literature demonstrates health benefits of social capital (social resources embedded within social networks). However, its effects are not always positive, particularly for certain subpopulations who are already disadvantaged. The CONtributions of social NEtworks to Community Thriving (CONNECT) study will use Participatory Action Research (PAR) to investigate social capital as a resource that benefits (or hinders) racially minoritised communities and their mental health. The CONNECT study was designed within a partnership with community organisations and responds to local policy in two South-East London Boroughs, thereby providing potential channels for the action component of PAR. Taking an anti-racism lens, we acknowledge the underpinning role of racism in creating health inequities. We apply an intersectional framework to be considerate of overlapping forms of oppression such as age, gender, socioeconomic status, and sexual orientation as an essential part of developing effective strategies to tackle health inequities. Key components of this mixed methods PAR study include (1) involving racialised minority community members as peer researchers in the team (2) collecting and analysing primary qualitative data via interviews, photovoice, and community mapping workshops, (3) developing relevant research questions guided by peer researchers and collaborating organisations and analysing secondary quantitative data accordingly, (4) integrating qualitative and quantitative phases, and (5) working closely with community and policy partners to act on our findings and use our research for social change. The PAR approach will allow us to engage community (voluntary sector and government) and academic partners in decision making and help address imbalances in power and resource allocation. Knowledge generated through this collaborative approach will contribute to existing community initiatives, policies, and council strategies. This will ensure the views and experiences of racially minoritised communities drive the changes we are collaboratively committed to achieving.<br/

    Casting Light on the Distinctive Contribution of Social Work in Multidisciplinary Teams for Older People

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    The current policy emphasis in adult social care in England is on promoting independence, preventing or delaying the need for more intensive support and the provision of personalised services. However, there is little evidence available on how social workers (SWs) identify and meet the complex needs of older service users in practice. In this article, we present findings from a study of innovative social work practice with older adults in England (2018–2019). We present five case studies of social care and integrated services in which SWs are integral team members. Twenty-one individuals participated in interviews; this included service managers and practitioners with social work backgrounds, and other professionals, including nurses and occupational therapists. Specific practices contributing to innovative service delivery included: the strong demonstration of social work values influencing the practice of multidisciplinary teams; positive risk management; importance of timing and ensuring continuity of relationships; and, the proactive application of legal knowledge to promote older people’s rights. While some of these features can be seen as returning to the ‘heart’ of social work, we argue that they are promising in forging new paths for social work with older people that turn away from more managerialist- and procedurally driven approaches
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