4,581 research outputs found

    High resolution spectroscopic analysis of seven giants in the bulge globular cluster NGC 6723

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    Globular clusters associated with the Galactic bulge are important tracers of stellar populations in the inner Galaxy. High resolution analysis of stars in these clusters allows us to characterize them in terms of kinematics, metallicity, and individual abundances, and to compare these fingerprints with those characterizing field populations. We present iron and element ratios for seven red giant stars in the globular cluster NGC~6723, based on high resolution spectroscopy. High resolution spectra (R48 000R\sim48~000) of seven K giants belonging to NGC 6723 were obtained with the FEROS spectrograph at the MPG/ESO 2.2m telescope. Photospheric parameters were derived from 130\sim130 FeI and FeII transitions. Abundance ratios were obtained from line-to-line spectrum synthesis calculations on clean selected features. An intermediate metallicity of [Fe/H]=0.98±0.08=-0.98\pm0.08 dex and a heliocentric radial velocity of vhel=96.6±1.3 kms1v_{hel}=-96.6\pm1.3~km s^{-1} were found for NGC 6723. Alpha-element abundances present enhancements of [O/Fe]=0.29±0.18[O/Fe]=0.29\pm0.18 dex, [Mg/Fe]=0.23±0.10[Mg/Fe]=0.23\pm0.10 dex, [Si/Fe]=0.36±0.05[Si/Fe]=0.36\pm0.05 dex, and [Ca/Fe]=0.30±0.07[Ca/Fe]=0.30\pm0.07 dex. Similar overabundance is found for the iron-peak Ti with [Ti/Fe]=0.24±0.09[Ti/Fe]=0.24\pm0.09 dex. Odd-Z elements Na and Al present abundances of [Na/Fe]=0.00±0.21[Na/Fe]=0.00\pm0.21 dex and [Al/Fe]=0.31±0.21[Al/Fe]=0.31\pm0.21 dex, respectively. Finally, the s-element Ba is also enhanced by [Ba/Fe]=0.22±0.21[Ba/Fe]=0.22\pm0.21 dex. The enhancement levels of NGC 6723 are comparable to those of other metal-intermediate bulge globular clusters. In turn, these enhancement levels are compatible with the abundance profiles displayed by bulge field stars at that metallicity. This hints at a possible similar chemical evolution with globular clusters and the metal-poor of the bulge going through an early prompt chemical enrichment

    Observational study on lameness recovery in 10 dogs affected by iliopsoas injury and submitted to a physiotherapeutic approach

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    This preliminary study has investigated the outcome of physiotherapy in 10 dogs affected by a primary lesion of the iliopsoas muscle and the potential effects of sex, age, and breed on recovery. Ten dogs with primary injury of the iliopsoas muscle were retrospectively included in this study. Dogs were submitted to a rehabilitation program, characterized by a multimodal approach, including physical therapies and modalities. After recovery, patients were submitted to a further support period of rehabilitation to promote muscle strengthening and limit injury recurrence during their return to normal functional and sports activity. Border collies were highly represented. The recovery of lameness occurred after a mean of 22.6 ± 14.7 (median 18) days with a median number of five sessions. None of the examined variables affected the recovery time, except for the border collie breed, which showed a significantly faster recovery time; however, there was no difference between the breeds with regard to the number of sessions. Multimodal rehabilitation therapy may promote lameness recovery of mild-to-moderate iliopsoas lesions within 3 weeks. This preliminary study reports a clinical approach and recovery of primary iliopsoas lesions, findings that can provide clinicians with useful prognostic information for dogs involved in sports activities

    Variable stars and stellar populations in Andromeda XXI: II. Another merged galaxy satellite of M31?

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    B and V time-series photometry of the M31 dwarf spheroidal satellite Andromeda XXI (And XXI) was obtained with the Large Binocular Cameras at the Large Binocular Telescope. We have identified 50 variables in And XXI, of which 41 are RR Lyrae stars (37 fundamental-mode RRab, and 4 first-overtone RRc, pulsators) and 9 are Anomalous Cepheids (ACs). The average period of the RRab stars ( = 0.64 days) and the period-amplitude diagram place And~XXI in the class of Oosterhoff II - Oosterhoff-Intermediate objects. From the average luminosity of the RR Lyrae stars we derived the galaxy distance modulus of (m-M)0_0=24.40±0.1724.40\pm0.17 mag, which is smaller than previous literature estimates, although still consistent with them within 1 σ\sigma. The galaxy color-magnitude diagram shows evidence for the presence of three different stellar generations in And~XXI: 1) an old (\sim 12 Gyr) and metal poor ([Fe/H]=-1.7 dex) component traced by the RR Lyrae stars; 2) a slightly younger (10-6 Gyr) and more metal rich ([Fe/H]=-1.5 dex) component populating the red horizontal branch, and 3) a young age (\sim 1 Gyr) component with same metallicity, that produced the ACs. Finally, we provide hints that And~XXI could be the result of a minor merging event between two dwarf galaxies.Comment: accepted for publications in Ap

    Military Working Dogs Operating in Afghanistan Theater: Comparison between Pre-and Post-Mission Blood Analyses to Monitor Physical Fitness and Training

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    The intergovernmental organization known as the United Nations (UN) was born “to maintain international peace and security” through different operations and tasks, including “mine action” and “explosive detection”. Explosives are the most frequent cause of injuries in military personnel and an enormous danger for civilians. The role of explosive detection dogs (EDDs) and mine detection dogs has gained great consideration over time, leading to their intense use in military operations. Literature regarding working injuries reported by EDDs during missions is limited. The aim of the present study is to investigate the hematological changes that occurred between pre-and post-mission blood analyses in military working dogs deployed to Afghanistan in order to evaluate signs of health problems or physical adjustments. Examining the clinical records, only three dogs reported a medical issue, one with gastric dilatation-volvulus (GDV), and two with lameness episodes. Lack of health issues occurring during the missions was reflected by the absence of significant differences between pre-and post-mission blood analyses. Blood results were also examined by dividing the EDDs into groups considering age at departure, sex, breed and mission length. A few categories demonstrated significant changes in some parameters; however, the mean values were always included in the ranges of normality, indicating that their physical fitness and training were adequate for the required tasks

    The Cepheids of NGC1866: A Precise Benchmark for the Extragalactic Distance Scale and Stellar Evolution from Modern UBVI Photometry

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    We present the analysis of multiband time-series data for a sample of 24 Cepheids in the field of the Large Magellanic Cloud cluster NGC1866. Very accurate BVI VLT photometry is combined with archival UBVI data, covering a large temporal window, to obtain precise mean magnitudes and periods with typical errors of 1-2% and of 1 ppm, respectively. These results represent the first accurate and homogeneous dataset for a substantial sample of Cepheid variables belonging to a cluster and hence sharing common distance, age and original chemical composition. Comparisons of the resulting multiband Period-Luminosity and Wesenheit relations to both empirical and theoretical results for the Large Magellanic Cloud are presented and discussed to derive the distance of the cluster and to constrain the mass-luminosity relation of the Cepheids. The adopted theoretical scenario is also tested by comparison with independent calibrations of the Cepheid Wesenheit zero point based on trigonometric parallaxes and Baade-Wesselink techniques. Our analysis suggests that a mild overshooting and/or a moderate mass loss can affect intermediate-mass stellar evolution in this cluster and gives a distance modulus of 18.50 +- 0.01 mag. The obtained V,I color-magnitude diagram is also analysed and compared with both synthetic models and theoretical isochrones for a range of ages and metallicities and for different efficiencies of core overshooting. As a result, we find that the age of NGC1866 is about 140 Myr, assuming Z = 0.008 and the mild efficiency of overshooting suggested by the comparison with the pulsation models.Comment: 13 pages, 10 figures, accepted in MNRAS (2016 January 14

    Cystic echinococcosis in water buffaloes (Bubalus bubalis)

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    An epidemiological and molecular survey of cystic echinococcosis (CE) caused by Echinococcus granulosus in the water buffalo (Bubalus bubalis) of the Italian Mediterranean breed was carried out in the Campania region of southern Italy. Out of a total of 799 water buffaloes examined at slaughterhouses, 80 (10.0%) were found infected. The molecular study was performed on 58 hydatid cysts in order to determine the E. granulosus strain(s) present in this host. A region of cytocrome c oxydase 1 gene (CO1) was amplified by polymerase chain reaction and the PCR products were then purified and sequenced. DNA amplification of the partial CO1 gene gave a 446 bp fragment for all isolates examined. After sequencing, a region of 419 bp was identified for each sample. Thirty-two isolates were identified as the common sheep strain G1, 15 as the buffalo strain G3, 3 as the Tasmanian sheep strain G2, and 3 as the G1 c genotype (GenBank AF458873). In addition, 5 isolates presented 99% identity with the G2 genotype (Tasmanian sheep strain)

    First studies on Giardia duodenalis in the water buffalo

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    A cross-sectional survey of Giardia duodenalis infection in the water buffalo was carried out in Central Italy. The survey was conducted on a sample of 90 farms, selected using a grid approach within a Geographical Information System, followed by proportional allocation. On each farm, faecal samples were collected from three to five asymptomatic buffalo calves, aged from 1 to 9 weeks (total number = 347). Each faecal sample was tested for the presence of copro-antigens of G. duodenalis using a commercially available ELISA. Out of the 90 farms, 27 (30.0%) resulted positive. With respect to animals, out of the 347 faecal samples, 63 (18.1%) were found to have antigens of G. duodenalis. The results of the logistic regression model showed a positive association between the positivity to G. duodenalis and the presence of sheep on farm

    Stellar Archaeology in the Galactic halo with the Ultra-Faint Dwarfs: VI. Ursa Major II

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    We present a B, V color-magnitude diagram (CMD) of the Milky Way dwarf satellite Ursa Major II (UMa II), spanning the magnitude range from V ~ 15 to V ~ 23.5 mag and extending over a 18 {\times} 18 arcmin2 area centered on the galaxy. Our photometry goes down to about 2 magnitudes below the galaxy's main sequence turn-off, that we detected at V ~ 21.5 mag. We have discovered a bona-fide RR Lyrae variable star in UMa II, which we use to estimate a conservative dereddened distance modulus for the galaxy of (m-M)0 = 17.70{\pm}0.04{\pm}0.12 mag, where the first error accounts for the uncertainties of the calibrated photometry, and the second reflects our lack of information on the metallicity of the star. The corresponding distance to UMa II is 34.7 {\pm} 0.6 ({\pm} 2.0) kpc. Our photometry shows evidence of a spread in the galaxy subgiant branch, compatible with a spread in metal abundance in the range between Z=0.0001 and Z=0.001. Based on our estimate of the distance, a comparison of the fiducial lines of the Galactic globular clusters (GCs) M68 and M5 ([Fe/H]=-2.27 {\pm} 0.04 dex and -1.33 {\pm} 0.02 dex, respectively), with the position on the CMD of spectroscopically confirmed galaxy members, may suggest the existence of stellar populations of different metal abundance/age in the central region of UMa II.Comment: To appear in Ap
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