101 research outputs found

    A workforce survey of Australian chiropractic: The profile and practice features of a nationally representative sample of 2,005 chiropractors

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    © 2017 The Author(s). Background: This paper reports the profile of the Australian chiropractic workforce and characteristics of chiropractic care from a large nationally-representative sample of practitioners. Methods: A 21-item questionnaire examining practitioner, practice and clinical management characteristics was distributed to all registered chiropractors (n=4,684) in Australia in 2015 via both online and hard copy mail out. Results: The survey attracted a response rate of 43% (n=2,005), and the sample is largely representative of the national chiropractic workforce on a number of key indicators. The average age of the chiropractors was 42.1 years, nearly two-thirds are male, and the vast majority hold a bachelor degree or higher qualification. Australian chiropractors are focused upon treating people across a wide age range who mainly present with musculoskeletal conditions. Australian chiropractors have referral relationships with a range of conventional, allied health and complementary medicine (CAM) providers. Conclusion: The chiropractic profession represents a substantial component of the contemporary Australian health care system with chiropractors managing an estimated 21.3 million patient visits per year. While the Australian chiropractic workforce is well educated, research engagement and research capacity remains sub-optimal and there is much room for further capacity building to help chiropractic reach full potential as a key integrated profession within an evidence-based health care system. Further rich, in-depth research is warranted to improve our understanding of the role of chiropractic within the Australian health care system

    The GRAVITY fringe tracker: correlation between optical path residuals and atmospheric parameters

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    After the first year of observations with the GRAVITY fringe tracker, we compute correlations between the optical path residuals and atmospheric and astronomical parameters. The median residuals of the optical path residuals are 180 nm on the ATs and 270 nm on the UTs. The residuals are uncorrelated with the target magnitudes for Kmag below 5.5 on ATs (9 on UTs). The correlation with the coherence time is however extremely clear, with a drop-off in fringe tracking performance below 3 ms.Comment: submitted to SPIE Astronomical Telescopes & Instrumentation 201

    A cross-sectional examination of the profile of chiropractors recruited to the Australian Chiropractic Research Network (ACORN): A sustainable resource for future chiropractic research

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    © 2017 Article author(s) (or their employer(s) unless otherwise stated in the text of the article). Objectives The Australian Chiropractic Research Network (ACORN) practice-based research network (PBRN) cohort was established to provide sustainable infrastructure necessary to address lack of rigorous investigation and to bridge the research-practice gap focused on chiropractic care for future years. This paper presents the profile of chiropractors recruited to the ACORN PBRN, a nationally representative sample of chiropractors working in Australia. Design Cross-sectional analysis of baseline data from a cohort study of chiropractors in Australia. Setting All registered chiropractors in Australia were invited to participate in the ACORN study and those who completed a practitioner questionnaire and consent form were included in the PBRN cohort. Participants A total of 1680 chiropractors (36%) were recruited to the cohort database. The average age of the PBRN participants is 41.9 years and 63% are male. The vast majority of the PBRN participants hold a university degree. Results General practitioners were identified as the most popular referral source for chiropractic care and low back pain and neck pain were the most common conditions â € often' treated by the PBRN chiropractors. The chiropractors in this PBRN cohort rated high velocity, low amplitude adjustment/manipulation/mobilisation as the most commonly used technique/method and soft tissue therapy as the most frequently employed musculoskeletal intervention in their patient management. Conclusions The ACORN PBRN cohort constitutes the largest coverage of any single healthcare profession via a national voluntary PBRN providing a sustainable resource for future follow-up. The ACORN cohort provides opportunities for further nested substudies related to chiropractic care, chiropractors, their patients and a vast range of broader healthcare issues with a view to helping build a diverse but coordinated research programme and further research capacity building around Australian chiropractic

    Identification of z~>2 Herschel 500 micron sources using color-deconfusion

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    We present a new method to search for candidate z~>2 Herschel 500{\mu}m sources in the GOODS-North field, using a S500{\mu}m/S24{\mu}m "color deconfusion" technique. Potential high-z sources are selected against low-redshift ones from their large 500{\mu}m to 24{\mu}m flux density ratios. By effectively reducing the contribution from low-redshift populations to the observed 500{\mu}m emission, we are able to identify counterparts to high-z 500{\mu}m sources whose 24{\mu}m fluxes are relatively faint. The recovery of known z~4 starbursts confirms the efficiency of this approach in selecting high-z Herschel sources. The resulting sample consists of 34 dusty star-forming galaxies at z~>2. The inferred infrared luminosities are in the range 1.5x10^12-1.8x10^13 Lsun, corresponding to dust-obscured star formation rates (SFRs) of ~260-3100 Msun/yr for a Salpeter IMF. Comparison with previous SCUBA 850{\mu}m-selected galaxy samples shows that our method is more efficient at selecting high-z dusty galaxies with a median redshift of z=3.07+/-0.83 and 10 of the sources at z~>4. We find that at a fixed luminosity, the dust temperature is ~5K cooler than that expected from the Td-LIR relation at z<1, though different temperature selection effects should be taken into account. The radio-detected subsample (excluding three strong AGN) follows the far-infrared/radio correlation at lower redshifts, and no evolution with redshift is observed out to z~5, suggesting that the far-infrared emission is star formation dominated. The contribution of the high-z Herschel 500{\mu}m sources to the cosmic SFR density is comparable to that of SMG populations at z~2.5 and at least 40% of the extinction-corrected UV samples at z~4 (abridged).Comment: 33 pages in emulateapj format, 24 figures, 2 tables, accepted for publication in the ApJ

    Nuclear Saturation with in-Medium Meson Exchange Interactions

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    We show that the assumption of dropping meson masses together with conventional many-body effects, implemented in the relativistic Dirac-Brueckner formalism, explains nuclear saturation. We use a microscopic model for correlated 2π2\pi exchange and include the standard many-body effects on the in-medium pion propagation, which initially increase the attractive nucleon-nucleon (NNNN) potential with density. For the vector meson exchanges in both the ππ\pi\pi and NNNN sector, we assume Brown-Rho scaling which---in concert with `chiral' ππ\pi\pi contact interactions---reduces the attraction at higher densities.Comment: 5 pages REVTeX, 2 eps-figures included, submitted to Phys. Rev. Let

    Discovery of a rich proto-cluster at z=2.9 and associated diffuse cold gas in the VIMOS Ultra-Deep Survey (VUDS)

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    [Abridged] We characterise a massive proto-cluster at z=2.895 that we found in the COSMOS field using the spectroscopic sample of the VIMOS Ultra-Deep Survey (VUDS). This is one of the rare structures at z~3 not identified around AGNs or radio galaxies, so it is an ideal laboratory to study galaxy formation in dense environments. The structure comprises 12 galaxies with secure spectroscopic redshift in an area of 7'x8', in a z bin of Dz=0.016. The measured galaxy number overdensity is delta_g=12+/-2. This overdensity has total mass of M~8.1x10^(14)M_sun in a volume of 13x15x17 Mpc^3. Simulations indicate that such an overdensity at z~2.9 is a proto-cluster that will collapse in a cluster of total mass M~2.5x10^(15)M_sun at z=0. We compare the properties of the galaxies within the overdensity with a control sample at the same z but outside the overdensity. We did not find any statistically significant difference between the properties (stellar mass, SFR, sSFR, NUV-r, r-K) of the galaxies inside and outside the overdensity. The stacked spectrum of galaxies in the overdensity background shows a significant absorption feature at the wavelength of Lya redshifted at z=2.895 (lambda=4736 A), with a rest frame EW = 4+/- 1.4 A. Stacking only background galaxies without intervening sources at z~2.9 along their line of sight, we find that this absorption feature has a rest frame EW of 10.8+/-3.7 A, with a detection S/N of ~4. These EW values imply a high column density (N(HI)~3-20x10^(19)cm^(-2)), consistent with a scenario where such absorption is due to intervening cold gas streams, falling into the halo potential wells of the proto-cluster galaxies. However, we cannot exclude the hypothesis that this absorption is due to the diffuse gas within the overdensity.Comment: 15 pages, 9 figures, accepted for publication in A&A (revised version after referee's comments and language editing

    The VIMOS Ultra Deep Survey First Data Release: spectra and spectroscopic redshifts of 698 objects up to z~6 in CANDELS

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    This paper describes the first data release (DR1) of the VIMOS Ultra Deep Survey (VUDS). The DR1 includes all low-resolution spectroscopic data obtained in 276.9 arcmin2 of the CANDELS-COSMOS and CANDELS-ECFDS survey areas, including accurate spectroscopic redshifts z_spec and individual spectra obtained with VIMOS on the ESO-VLT. A total of 698 objects have a measured redshift, with 677 galaxies, two type-I AGN and a small number of 19 contaminating stars. The targets of the spectroscopic survey are selected primarily on the basis of their photometric redshifts to ensure a broad population coverage. About 500 galaxies have z_spec>2, 48 with z_spec>4, and the highest reliable redshifts reach beyond z_spec=6. This dataset approximately doubles the number of galaxies with spectroscopic redshifts at z>3 in these fields. We discuss the general properties of the sample in terms of the spectroscopic redshift distribution, the distribution of Lyman-alpha equivalent widths, and physical properties including stellar masses M_star and star formation rates (SFR) derived from spectral energy distribution fitting with the knowledge of z_spec. We highlight the properties of the most massive star-forming galaxies, noting the large range in spectral properties, with Lyman-alpha in emission or in absorption, and in imaging properties with compact, multi-component or pair morphologies. We present the catalogue database and data products. All data are publicly available and can be retrieved from a dedicated query-based database available at http://cesam.lam.fr/vuds.Comment: 11 pages, 6 figures, submitted to A&

    The evolution of clustering length, large-scale bias and host halo mass at 2<z<5 in the VIMOS Ultra Deep Survey (VUDS)

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    We investigate the evolution of galaxy clustering for galaxies in the redshift range 2.0<zz<5.0 using the VIMOS Ultra Deep Survey (VUDS). We present the projected (real-space) two-point correlation function wp(rp)w_p(r_p) measured by using 3022 galaxies with robust spectroscopic redshifts in two independent fields (COSMOS and VVDS-02h) covering in total 0.8 deg2^2. We quantify how the scale dependent clustering amplitude r0r_0 changes with redshift making use of mock samples to evaluate and correct the survey selection function. Using a power-law model ξ(r)=(r/r0)γ\xi(r) = (r/r_0)^{-\gamma} we find that the correlation function for the general population is best fit by a model with a clustering length r0r_0=3.950.54+0.48^{+0.48}_{-0.54} h1^{-1}Mpc and slope γ\gamma=1.80.06+0.02^{+0.02}_{-0.06} at zz~2.5, r0r_0=4.35±\pm0.60 h1^{-1}Mpc and γ\gamma=1.60.13+0.12^{+0.12}_{-0.13} at zz~3.5. We use these clustering parameters to derive the large-scale linear galaxy bias bLPLb_L^{PL}, between galaxies and dark matter. We find bLPLb_L^{PL} = 2.68±\pm0.22 at redshift zz~3 (assuming σ8\sigma_8 = 0.8), significantly higher than found at intermediate and low redshifts. We fit an HOD model to the data and we obtain that the average halo mass at redshift zz~3 is MhM_h=1011.75±0.23^{11.75\pm0.23} h1^{-1}M_{\odot}. From this fit we confirm that the large-scale linear galaxy bias is relatively high at bLHODb_L^{HOD} = 2.82±\pm0.27. Comparing these measurements with similar measurements at lower redshifts we infer that the star-forming population of galaxies at zz~3 should evolve into the massive and bright (MrM_r<-21.5) galaxy population which typically occupy haloes of mass Mh\langle M_h\rangle = 1013.9^{13.9} h1^{-1} MM_{\odot} at redshift zz=0.Comment: 19 pages, 10 figures, submitted to A&

    Estimativa da radiação solar global de Bebedouro (PE) utilizando temperaturas máxima e mínima do ar.

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    O trabalho apresenta a avaliação do desempenho do modelo BRISTOW e CAMPBELL e propõe um modelo para estimar a radiação solar global, utilizando a variáveis meteorológicas temperaturas máxima e mínima do ar na localidade de Bebedouro (PE)

    The Lyman Continuum escape fraction of galaxies at z=3.3 in the VUDS-LBC/COSMOS field

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    The Lyman continuum (LyC) flux escaping from high-z galaxies into the IGM is a fundamental quantity to understand the physical processes involved in the reionization epoch. We have investigated a sample of star-forming galaxies at z~3.3 in order to search for possible detections of LyC photons escaping from galaxy halos. UV deep imaging in the COSMOS field obtained with the prime focus camera LBC at the LBT telescope was used together with a catalog of spectroscopic redshifts obtained by the VIMOS Ultra Deep Survey (VUDS) to build a sample of 45 galaxies at z~3.3 with L>0.5L*. We obtained deep LBC images of galaxies with spectroscopic redshifts in the interval 3.27<z<3.40 both in the R and deep U bands. A sub-sample of 10 galaxies apparently shows escape fractions>28% but a detailed analysis of their properties reveals that, with the exception of two marginal detections (S/N~2) in the U band, all the other 8 galaxies are most likely contaminated by the UV flux of low-z interlopers located close to the high-z targets. The average escape fraction derived from the stacking of the cleaned sample was constrained to fesc_rel<2%. The implied HI photo-ionization rate is a factor two lower than that needed to keep the IGM ionized at z~3, as observed in the Lyman forest of high-z QSO spectra or by the proximity effect. These results support a scenario where high redshift, relatively bright (L>0.5L*) star-forming galaxies alone are unable to sustain the level of ionization observed in the cosmic IGM at z~3. Star-forming galaxies at higher redshift and at fainter luminosities (L<<L*) can be the major contributors to the reionization of the Universe only if their physical properties are subject to rapid changes from z~3 to z~6-10. Alternatively, ionizing sources could be discovered looking for fainter sources among the AGN population at high-z.Comment: 21 pages, 9 figures. Accepted for publication in A&
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