563 research outputs found

    Impact of simulated patients on physiotherapy students' skill performance in cardiorespiratory practice classes: a pilot study.

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    Purpose: To date, no evidence exists that high-fidelity simulation improves skill development among physiotherapy students in the university setting. With pressures to reduce costs and maintain or improve the quality of the learning experience, and with pressures on clinical placement, it is essential to investigate methods that might improve students’ skill performance before they undertake clinical practice. Our study set out to investigate (1) the impact of using simulated patients (SPs) in a practical class on physiotherapy students’ skill acquisition and (2) the students’ reflections on the intervention. Method: We devised a pilot study using a single-centre randomized controlled trial. A total of 28 undergraduate physiotherapy students, matched using previous practical examination grades, undertook a 2-hour practical class in which they practised their core cardiorespiratory skills. Pre-session resources were identical. The control group practised on peers; the intervention group practised on SPs. The students’ skill performance was assessed 2 weeks later using the Mini-Clinical Evaluation Exercise (MiniCEX), including gathering qualitative data from the students’ reflections. Twenty-eight students undertook the practical class and subsequent MiniCEX assessment. Results: A statistically significant difference was found for all aspects of the MiniCEX except medical interview ( p = 0.07) and physical interview (p = 0.69), and a large effect size was found for all areas except physical interview (0.154) and medical interview (0.378). The students’ reflections focused on three key themes: behaviours and attitudes, teaching the active cycle of breathing technique, and feedback. Conclusions: Our findings suggest that interacting with SPs improves student skill performance, but further research using a larger sample size and an outcome measure validated for this population is required to confirm this

    Barcoding of the cytochrome oxidase I (COI) indicates a recent introduction of Ciona savignyi into New Zealand and provides a rapid method for Ciona species discrimination

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    Mitochondrial cytochrome oxidase I (COI) gene sequencing (DNA barcoding) of Ciona specimens from New Zealand (NZ) led to the first record of the solitary ascidian Ciona savignyi in the Southern Hemisphere. We sought to quantify C. savignyi COI genetic diversity around the NZ archipelago and to compare this with diversity within C. savignyi's native range in the north-west Pacific. Ciona savignyi specimens were collected from two NZ sites and from three sites around Japan. COI sequences (595 bp) were amplified and measures of genetic diversity were calculated. Based on differences between their COI sequences we developed a PCR-based assay to distinguish C. savignyi from the morphologically similar C. intestinalis. A total of 12 C. savignyi COI haplotypes were recovered from the 76 samples. Of the four haplotypes observed in NZ, two were unique. From the 10 haplotypes observed in the Japan samples, eight were unique. The C. savignyi populations in Japan were found to contain higher haplotype diversity when compared with those in NZ. The NZ samples contained only a small subset of the haplotype variation of the Japan samples, however, NZ samples did harbor two haplotypes not observed in the Japan samples. A PCR-based assay developed from the COI sequences was able to reliably discriminate the two Ciona species. The low COI genetic diversity within the two NZ C. savignyi populations sampled is consistent with a founder effect associated loss of genetic diversity. The robust PCR-based assay for distinguishing C. savignyi and C. intestinalis may find application in ecological and taxonomic studies and can be applied to both archival materials and live animals

    Observational Artifacts of NuSTAR: Ghost Rays and Stray Light

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    The Nuclear Spectroscopic Telescope Array (NuSTAR), launched in June 2012, flies two conical approximation Wolter-I mirrors at the end of a 10.15m mast. The optics are coated with multilayers of Pt/C and W/Si that operate from 3--80 keV. Since the optical path is not shrouded, aperture stops are used to limit the field of view from background and sources outside the field of view. However, there is still a sliver of sky (~1.0--4.0 degrees) where photons may bypass the optics altogether and fall directly on the detector array. We term these photons Stray-light. Additionally, there are also photons that do not undergo the focused double reflections in the optics and we term these Ghost Rays. We present detailed analysis and characterization of these two components and discuss how they impact observations. Finally, we discuss how they could have been prevented and should be in future observatories.Comment: Published in Journal of Astronomical Telescopes, Instruments, and Systems. Open Access. http://dx.doi.org/10.1117/1.JATIS.3.4.04400

    Development of thermally formed glass optics for astronomical hard x-ray telescopes

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    The next major observational advance in hard X-ray/soft gamma-ray astrophysics will come with the implementation of telescopes capable of focusing 10-200 keV radiation. Focusing allows high signal-to-noise imaging and spectroscopic observations of many sources in this band for the first time. The recent development of depth-graded multilayer coatings has made the design of telescopes for this bandpass practical, however the ability to manufacture inexpensive substrates with appropriate surface quality and figure to achieve sub-arcminute performance has remained an elusive goal. In this paper, we report on new, thermally-formed glass micro-sheet optics capable of meeting the requirements of the next-generation of astronomical hard X-ray telescopes

    W/SiC x-ray multilayers optimized for use above 100 keV

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    We have developed a new depth-graded multilayer system comprising W and SiC layers, suitable for use as hard x-ray reflective coatings operating in the energy range 100-200 keV. Grazing-incidence x-ray reflectance at E = 8 keV was used to characterize the interface widths, as well as the temporal and thermal stability in both periodic and depth-graded W/SiC structures, whereas synchrotron radiation was used to measure the hard x-ray reflectance of a depth-graded multilayer designed specifically for use in the range E ~150-170 keV. We have modeled the hard x-ray reflectance using newly derived optical constants, which we determined from reflectance versus incidence angle measurements also made using synchrotron radiation, in the range E = 120-180 keV. We describe our experimental investigation in detail, compare the new W/SiC multilayers with both W/Si and W/B4C films that have been studied previously, and discuss the significance of these results with regard to the eventual development of a hard x-ray nuclear line telescope

    Broadband X-ray Imaging and Spectroscopy of the Crab Nebula and Pulsar with NuSTAR

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    We present broadband (3 -- 78 keV) NuSTAR X-ray imaging and spectroscopy of the Crab nebula and pulsar. We show that while the phase-averaged and spatially integrated nebula + pulsar spectrum is a power-law in this energy band, spatially resolved spectroscopy of the nebula finds a break at \sim9 keV in the spectral photon index of the torus structure with a steepening characterized by ΔΓ0.25\Delta\Gamma\sim0.25. We also confirm a previously reported steepening in the pulsed spectrum, and quantify it with a broken power-law with break energy at \sim12 keV and ΔΓ0.27\Delta\Gamma\sim0.27. We present spectral maps of the inner 100\as\ of the remnant and measure the size of the nebula as a function of energy in seven bands. These results find that the rate of shrinkage with energy of the torus size can be fitted by a power-law with an index of γ=0.094±0.018\gamma = 0.094\pm 0.018, consistent with the predictions of Kennel and Coroniti (1984). The change in size is more rapid in the NW direction, coinciding with the counter-jet where we find the index to be a factor of two larger. NuSTAR observed the Crab during the latter part of a γ\gamma-ray flare, but found no increase in flux in the 3 - 78 keV energy band

    Targeted disruption of the orphan receptor Gpr151 does not alter pain-related behaviour despite a strong induction in dorsal root ganglion expression in a model of neuropathic pain

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    BACKGROUND: Gpr151 is an orphan GPCR whose function is unknown. The restricted pattern of neuronal expression in the habenula, dorsal horn of the spinal cord and dorsal root ganglion plus homology with the galanin family of receptors imply a role in nociception. RESULTS: Real-time quantitative RT-PCR demonstrated a 49.9 ± 2.9 fold highly significant (P < 0.001) increase in Gpr151 mRNA expression in the dorsal root ganglion 7 days after the spared nerve injury model of neuropathic pain. Measures of acute, inflammatory and neuropathic pain behaviours were not significantly different using separate groups of Gpr151 loss-of-function mutant mice and wild-type controls. Galanin at concentrations between 100 nM and 10 μM did not induce calcium signalling responses in ND7/23 cells transfected with Gpr151. CONCLUSIONS: Our results indicate that despite the very large upregulation in the DRG after a nerve injury model of neuropathic pain, the Gpr151 orphan receptor does not appear to be involved in the modulation of pain-related behaviours. Further, galanin is unlikely to be an endogenous ligand for Gpr151

    NuSTAR discovery of a cyclotron line in the accreting X-ray pulsar IGR J16393-4643

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    The high-mass X-ray binary and accreting X-ray pulsar IGR J16393-4643 was observed by NuSTAR in the 3-79 keV energy band for a net exposure time of 50 ks. We present the results of this observation which enabled the discovery of a cyclotron resonant scattering feature with a centroid energy of 29.3(+1.1/-1.3) keV. This allowed us to measure the magnetic field strength of the neutron star for the first time: B = (2.5+/-0.1)e12 G. The known pulsation period is now observed at 904.0+/-0.1 s. Since 2006, the neutron star has undergone a long-term spin-up trend at a rate of P' = -2e-8 s/s (-0.6 s per year, or a frequency derivative of nu' = 3e-14 Hz/s ). In the power density spectrum, a break appears at the pulse frequency which separates the zero slope at low frequency from the steeper slope at high frequency. This addition of angular momentum to the neutron star could be due to the accretion of a quasi-spherical wind, or it could be caused by the transient appearance of a prograde accretion disk that is nearly in corotation with the neutron star whose magnetospheric radius is around 2e8 cm.Comment: Accepted for publication in the Astrophysical Journal, 7 pages, 8 figures, 2 table

    Broadband X-ray Properties of the Gamma-ray Binary 1FGL J1018.6-5856

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    We report on NuSTAR, XMM-Newton and Swift observations of the gamma-ray binary 1FGL J1018.6-5856. We measure the orbital period to be 16.544+/-0.008 days using Swift data spanning 1900 days. The orbital period is different from the 2011 gamma-ray measurement which was used in the previous X-ray study of An et al. (2013) using ~400 days of Swift data, but is consistent with a new gamma-ray solution reported in 2014. The light curve folded on the new period is qualitatively similar to that reported previously, having a spike at phase 0 and broad sinusoidal modulation. The X-ray flux enhancement at phase 0 occurs more regularly in time than was previously suggested. A spiky structure at this phase seems to be a persistent feature, although there is some variability. Furthermore, we find that the source flux clearly correlates with the spectral hardness throughout all orbital phases, and that the broadband X-ray spectra measured with NuSTAR, XMM-Newton, and Swift are well fit with an unbroken power-law model. This spectrum suggests that the system may not be accretion-powered.Comment: 8 pages, 4 figures. Accepted for publication in Ap

    Phase-resolved NuSTAR and Swift-XRT Observations of Magnetar 4U 0142+61

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    We present temporal and spectral analysis of simultaneous 0.5-79 keV Swift-XRT and NuSTAR observations of the magnetar 4U 0142+61. The pulse profile changes significantly with photon energy between 3 and 35 keV. The pulse fraction increases with energy, reaching a value of ~20%, similar to that observed in 1E 1841-045 and much lower than the ~80% pulse fraction observed in 1E 2259+586. We do not detect the 55-ks phase modulation reported in previous Suzaku-HXD observations. The phase-averaged spectrum of 4U 0142+61 above 20 keV is dominated by a hard power law with a photon index, Γ\Gamma ~ 0.65, and the spectrum below 20 keV can be described by two blackbodies, a blackbody plus a soft power law, or by a Comptonized blackbody model. We study the full phase-resolved spectra using the electron-positron outflow model of Beloborodov (2013). Our results are consistent with the parameters of the active j-bundle derived from INTEGRAL data by Hascoet et al. (2014). We find that a significant degeneracy appears in the inferred parameters if the footprint of the j-bundle is allowed to be a thin ring instead of a polar cap. The degeneracy is reduced when the footprint is required to be the hot spot inferred from the soft X-ray data.Comment: 14 pages, 8 figures, 4 tables. Accepted for publication in Ap
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