830 research outputs found

    Experiments on Vortices in Rotating Superfluid 3He-A

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    A satellite peak has been observed in the NMR spectrum of rotating 3He-A; the peak intensity depends linearly on Ω at the high angular velocities, Ω=0.6−1.5 rad/s, needed to resolve it. The frequency shift of the satellite is independent of Ω. These results strongly suggest the existence of vortices in rotating 3He-A with the vortex density proportional to Ω. Another satellite peak also has been observed which probably is due to solitons.Peer reviewe

    High-throughput amplicon sequencing reveals distinct communities within a corroding concrete sewer system

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    This study investigated the variation in microbially induced concrete corrosion communities at different circumferential locations of a real sewer pipe and the effects of a wastewater flooding event on the community. Three distinct microbial community groups were found in different corrosion samples. The physico-chemical properties of the corrosion layers and the microbial communities were distinct for the cross-sectional positions within the pipe, ie ceiling, wall and tidal zones. The microbial communities detected from the same positions in the pipe were consistent over the length of the pipe, as well as being consistent between the replicate pipes. The dominating ceiling communities were members of the bacterial orders Rhodospirillales, Acidithiobacillales, Actinomycetales, Xanthomonadales and Acidobacteriales. The wall communities were composed of members of the Xanthomonadales, Hydrogenophilales, Chromatiales and Sphingobacteriales. The tidal zones were dominated by eight bacterial and one archaeal order, with the common physiological trait of anaerobic metabolism. Sewage flooding within the sewer system did not change the tidal and wall communities, although the corrosion communities in ceiling samples were notably different, becoming more similar to the wall and tidal samples. This suggests that sewage flooding has a significant impact on the corrosion community in sewers

    NMR Experiments on Rotating Superfluid 3He-A : Evidence for Vorticity

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    Experiments on rotating superfluid 3He-A in an open cylindrical geometry show a change in the NMR line shape as a result of rotation: The amplitude of the peak decreases in proportion to f(T)g(Ω), where Ω is the angular velocity of rotation; at the same time the line broadens. Near Tc, f(T) is a linear function of 1−T/Tc. At small velocities g(Ω)∝Ω. These observations are consistent with the existence of vortices in rotating 3He-A.Peer reviewe

    Angry opposition to government redress: when the structurally advantaged perceive themselves as relatively deprived

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    We examined (structurally advantaged) non-Aborigines' willingness for political action against government redress to (structurally disadvantaged) Aborigines in Australia. We found non-Aborigines opposed to government redress to be high in symbolic racism and to perceive their ingroup as deprived relative to Aborigines. However, only perceived relative deprivation was associated with feelings of group-based anger. In addition, consistent with relative deprivation and emotion theory, it was group-based anger that fully mediated a willingness for political action against government redress. Thus, the specific group-based emotion of anger explained why symbolic racism and relative deprivation promoted a willingness for political action against government redress to a structurally disadvantaged out-group. Theoretical and political implications are discussed

    Reproducibility of in vitro contracture test results in patients tested for malignant hyperthermia susceptibility.

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    BACKGROUND: The in vitro contracture test (IVCT) is the golden standard to diagnose malignant hyperthermia susceptibility (MHS). A high reproducibility is important for a high validity of a test. METHODS: We have therefore analyzed IVCT in 838 patients, investigated in two laboratories. Each halothane and caffeine test was performed in two muscle strips. The test results were analyzed with respect to reproducibility of abnormal outcomes within pairs of tested muscle strips and size of contractures, thresholds and quality criteria. The patients were tested according to the European Malignant Hyperthermia Group protocol (EMHG). To fulfill quality criteria in the EMHG protocol the twitch height should be 10 mN (1 g) or more. For the caffeine test a minimum contracture of 50 mN (5 g) or more at 32 mmol l-1 caffeine could be used as an alternative quality criterion RESULTS: There was better reproducibility with larger contractures. The correlation between size of contractures and fraction of muscle strips with abnormal contractures was 0.77 or larger. Contractures < 5 mN (0.5 g) were reproducible in less than half of the tests. There was no difference in reproducibility or size of contractures between tests fulfillling all quality criteria and those not fulfillling these criteria. CONCLUSIONS: IVCT responses close to cut off limits, i.e. <5 mN (0.5 g) in the EMHG protocol, are less reproducible and must scientifically be considered as less reliable. The clinical cut off limits must remain unchanged for reasons of clinical safety. The outcome of quality measurements does not influence the test results

    Effectiveness, cost-effectiveness and cost-benefit of a single annual professional intervention for the prevention of childhood dental caries in a remote rural Indigenous community

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    Background The aim of the study is to reduce the high prevalence of tooth decay in children in a remote, rural Indigenous community in Australia, by application of a single annual dental preventive intervention. The study seeks to (1) assess the effectiveness of an annual oral health preventive intervention in slowing the incidence of dental caries in children in this community, (2) identify the mediating role of known risk factors for dental caries and (3) assess the cost-effectiveness and cost-benefit of the intervention. Methods/design The intervention is novel in that most dental preventive interventions require regular re-application, which is not possible in resource constrained communities. While tooth decay is preventable, self-care and healthy habits are lacking in these communities, placing more emphasis on health services to deliver an effective dental preventive intervention. Importantly, the study will assess cost-benefit and cost-effectiveness for broader implementation across similar communities in Australia and internationally. Discussion There is an urgent need to reduce the burden of dental decay in these communities, by implementing effective, cost-effective, feasible and sustainable dental prevention programs. Expected outcomes of this study include improved oral and general health of children within the community; an understanding of the costs associated with the intervention provided, and its comparison with the costs of allowing new lesions to develop, with associated treatment costs. Findings should be generalisable to similar communities around the world. The research is registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), registration number ACTRN12615000693527; date of registration: 3rd July 2015

    The effect of geometrical presplit blast parameters on presplit quality at Kuusilampi open pit mine

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    In open pit mines, controlled blasting methods are used to reduce blast damage on the remaining rock mass, which increases the safety and economy of the operation. Presplitting is one of the most common controlled blasting methods used to achieve stable pit walls. The aim of this thesis is to discover suitable presplitting designs for the different areas of the Kuusilampi open pit mine. Furthermore, this thesis studied the connection between a geotechnical block model's rock mass quality estimates and the result of presplit blasting. This study has been conducted to improve the slope stability at the mine by improving the presplit blasting practices. This thesis consists of a historical review of presplitting practice at Kuusilampi open pit and presplitting tests. Presplitting tests were conducted with smaller diameter explosive cartridge than previously used and different borehole diameters, inclinations and spacings. The results were estimated based on visual inspection of the presplit faces and by calculating the half core factor, and over- and underbreak in cubic meters per square meter of presplit face. In this thesis, no major differences were found in the presplit results with the different presplit parameters. Furthermore, it was concluded that the greatest improvements to the slope stability at the Kuusilampi open pit could be achieved with modifications to the buffer row. Additionally, no connection was found between the rock mass quality estimate of the geotechnical block model and presplitting results, because the geotechnical block model was found to lack sufficient accuracy and resolution to represent the rock mass quality accurately
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