14,114 research outputs found

    Understanding World Heritage from the local perspective on the Ningaloo Coast, Western Australia

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    The remote Ningaloo Coast region, the location of Australiaā€™s largest fringing coral reef, was designated as World Heritage in 2011 because of its outstanding natural values

    Enhanced dielectrophoresis of nanocolloids by dimer formation

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    We investigate the dielectrophoretic motion of charge-neutral, polarizable nanocolloids through molecular dynamics simulations. Comparison to analytical results derived for continuum systems shows that the discrete charge distributions on the nanocolloids have a significant impact on their coupling to the external field. Aggregation of nanocolloids leads to enhanced dielectrophoretic transport, provided that increase in the dipole moment upon aggregation can overcome the related increase in friction. The dimer orientation and the exact structure of the nanocolloid charge distribution are shown to be important in the enhanced transport

    Plane-wave impulse approximation extraction of the neutron magnetic form factor from quasielastic ^3He(e,e') at Q^2=0.3 to 0.6 (GeV/c)^2

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    A high precision measurement of the transverse spin-dependent asymmetry A_T' in ^3He(e,e') quasielastic scattering was performed in Hall A at Jefferson Lab at values of the squared four-momentum transfer, Q^2, between 0.1 and 0.6 (GeV/c)^2. A_(T') is sensitive to the neutron magnetic form factor, G_M^n . Values of G_M^n at Q^2 = 0.1 and 0.2 (GeV/c)^2, extracted using Faddeev calculations, were reported previously. Here, we report the extraction of G_M^n for the remaining Q^2 values in the range from 0.3 to 0.6 (GeV/c)^2 using a plane-wave impulse approximation calculation. The results are in good agreement with recent precision data from experiments using a deuterium target

    Q^2 Evolution of the Neutron Spin Structure Moments using a ^3He Target

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    We have measured the spin structure functions g_1 and g_2 of ^3He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.058 GeV off a polarized ^3He target at a 15.5Ā° scattering angle. Excitation energies covered the resonance and the onset of the deep inelastic regions. We have determined for the first time the Q^2 evolution of Ī“_1(Q^2)=āˆ«_0^1g_1(x,Q^2)dx, Ī“_2(Q^2)=āˆ«_0^1g_2(x,Q^2)dx, and d_2(Q^2)=āˆ«_0^1x^2[2g_1(x,Q^2)+3g_2(x,Q^2)]dx for the neutron in the range 0.1 ā‰¤ Q^2 ā‰¤0.9ā€‰ā€‰GeV^2 with good precision. Ī“_1(Q^2) displays a smooth variation from high to low Q^2. The Burkhardt-Cottingham sum rule holds within uncertainties and d_2 is nonzero over the measured range

    Precision Measurement of the Spin-Dependent Asymmetry in the Threshold Region of ^3He(e, e')

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    We present the first precision measurement of the spin-dependent asymmetry in the threshold region of ^3He(e,eā€²) at Q^2 values of 0.1 and 0.2(GeV/c)^2. The agreement between the data and nonrelativistic Faddeev calculations which include both final-state interactions and meson-exchange current effects is very good at Q^2 = 0.1(GeV/c)^2, while a small discrepancy at Q^2 = 0.2(GeV/c)^2 is observed

    Q^2 Evolution of the Generalized Gerasimov-Drell-Hearn Integral for the Neutron using a ^3He Target

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    We present data on the inclusive scattering of polarized electrons from a polarized ^3He target at energies from 0.862 to 5.06 GeV, obtained at a scattering angle of 15.5Ā°. Our data include measurements from the quasielastic peak, through the nucleon resonance region, and beyond, and were used to determine the virtual photon cross-section difference Ļƒ_(1/2)-Ļƒ_(3/2). We extract the extended Gerasimov-Drell-Hearn integral for the neutron in the range of four-momentum transfer squared Q^2 of 0.1ā€“0.9ā€‰ā€Šā€ŠGeV^2

    Transverse Asymmetry A_Tā€² from the Quasielastic ^3He(e,eā€²) Process and the Neutron Magnetic Form Factor

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    We have measured the transverse asymmetry A_Tā€² in ^3He(e,eā€²) quasielastic scattering in Hall A at Jefferson Laboratory with high precision for Q^2 values from 0.1 to 0.6 (GeV/c)^2. The neutron magnetic form factor GMn was extracted based on Faddeev calculations for Q^2 = 0.1 and 0.2 (GeV/c)^2 with an experimental uncertainty of less than 2%

    Ningaloo coast region visitor statistics: collected for the Ningaloo destination modelling project

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    This Ningaloo Destination Modelling Project report provides the latest information about the characteristics and behaviours of visitors for the tourism industry, managers, and other research projects based in the Ningaloo Coastal Region. This region is defined as the coastal areas between Exmouth town site and Carnarvon town site in the Gascoyne region in the northwest of Western Australia. The Ningaloo Destination Modelling (NDM) project is a collaborative project between researchers from seven Australian universities and the Sustainable Tourism Cooperative Research Centre that will deliver a scenario planning tool that assesses the social, environmental and economic impact of tourism planning strategies in order to assist tourism planning in a region that relies on its unique natural attractions. The project is part of the Ningaloo Collaboration Cluster of projects and sits within the CSIRO Wealth from Oceans Flagship. The Ningaloo Destination Modelling project is cofounded by the STCRC and the CSIRO. The scenario planning tool is a numerical model of tourism, run through the computer modelling program Vensim, that relies on statistics that were gathered both through collaboration with other projects and collected by researchers affiliated with the project. This includes statistics from 1574 visitor surveys distributed between July 2007 and September 2008. While the visitor surveys were primarily collected for the purpose of providing reliable statistics for the model, they are also the most comprehensive resource available on visitorsā€™ characteristics and behaviour in the region. This technical report provides access to these statistics. Statistics are provided for the region as a whole and also divided into six subregions. The report includes an introductory chapter outlining the broader research program, the methodology employed to collect the statistics and background information on tourism to the region. The final two chapters provide information on three broad visitor types identified through factor analysis, and an estimation of tourism expenditure in the region. Based on the surveys, we estimate that expenditure in the region for the year ending September 2008 was 141million,with179,352visitorsstayingforanaverageof9.92nights.Averagenightlyexpenditurewas141 million, with 179,352 visitors staying for an average of 9.92 nights. Average nightly expenditure was 79.46. This is consistent with Carlson and Woodā€™s (2004) earlier study in the region that estimated annual expenditure to be $127 million

    Illness-Related Cognition, Distress and Adjustment in Functional Stroke Symptoms, Vascular Stroke, and Chronic Fatigue Syndrome

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    Background: High rates of psychological distress are reported in functional conditions and vascular stroke, but there is limited understanding of how patients with functional neurological symptoms in stroke settings respond to symptoms. Aims: This study compared patients with functional stroke symptoms to those with vascular stroke and chronic fatigue syndrome (CFS). Methods: A prospective cohort of 56 patients with functional stroke symptoms were age-gender matched to patients with vascular stroke and CFS. Analysis of variance compared groups on cognitive and behavioral responses to symptoms, psychological distress, and functioning. Sensitivity analyses controlled for known confounders. The proportions of clinical anxiety and depression were compared between groups. Results: The functional stroke symptom group had a higher proportion of clinical anxiety cases than the CFS group, and a higher proportion of clinical depression cases than the vascular stroke group. Patients with functional stroke symptoms reported the highest rate of ā€œdamage beliefsā€ and ā€œall-or-nothingā€ behaviors and greater symptom focusing and resting behavior than patients with vascular stroke. Limitations: Larger cohorts and a longitudinal design would strengthen study findings. Conclusion: Compared to patients with vascular stroke or CFS, patients with functional stroke symptoms show a somewhat distinct profile of illness-related beliefs and behaviors, as well as higher rates of clinical anxiety. Understanding such group differences provides some insights into aetiology and cognitive-behavioral responses. Appropriate support and referral should be available to patients with functional stroke symptoms to address distress and reduce the likelihood of severe impairment

    The extended star formation history of omega Centauri

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    For the first time, the abundances of a large sample of subgiant and turn-off region stars in omega Centauri have been measured, the data base being medium resolution spectroscopy from FORS2 at the VLT. Absolute iron abundances were derived for about 400 member stars from newly defined line indices with an accuracy of +/-0.15 dex. The abundances range between -2.2<[Fe/H]<-0.7 dex, resembling the large metallicity spread found for red giant branch stars. The combination of the spectroscopic results with the location of the stars in the colour magnitude diagram has been used to estimate ages for the individual stars. Whereas most of the metal-poor stars are consistent with a single old stellar population, stars with abundances higher than [Fe/H]=-1.3 dex are younger. The total age spread in omega Cent is about 3 Gyr. The monotonically increasing age-metallicity relation seems to level off above [Fe/H]=-1.0 dex. Whether the star formation in omega Cen occured continuously or rather episodically has to be shown by combining more accurate abundances with highest quality photometry.Comment: 4 pages, 3 figures, accepted for publication in Astronomy & Astrophysics (Letters
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