RR Lyrae Variables in the Local Group Dwarf Galaxy NGC 147

We investigate the RR Lyrae population in NGC 147, a dwarf satellite galaxy of M31 (Andromeda). We used both Thuan-Gunn g-band ground-based photometry from the literature and Hubble Space Telescope Wide Field Planetary Camera 2 archival data in the F555W and F814W passbands to investigate the pulsation properties of RR Lyrae variable candidates in NGC 147. These datasets represent the two extreme cases often found in RR Lyrae studies with respect to the phase coverage of the observations and the quality of the photometric measurements. Extensive artificial variable star tests for both cases were performed. We conclude that neither dataset is sufficient to confidently determine the pulsation properties of the NGC 147 RR Lyraes. Thus, while we can assert that NGC 147 contains RR Lyrae variables, and therefore a population older than ~10 Gyr, it is not possible at this time to use the pulsation properties of these RR Lyraes to study other aspects of this old population. Our results provide a good reference for gauging the completeness of RR Lyrae variable detection in future studies.Comment: Accepted for publication in The Astrophysical Journa

A Photometric Study of the Outer Halo Globular Cluster NGC 5824

Multi-wavelength CCD photometry over 21 years has been used to produce deep color-magnitude diagrams together with light curves for the variables in the Galactic globular cluster NGC 5824. Twenty-one new cluster RR Lyrae stars are identified, bringing the total to 47, of which 42 have reliable periods determined for the first time. The color-magnitude diagram is matched using BaSTI isochrones with age of $13$~Gyr. and reddening is found to be $E(B-V) = 0.15 \pm0.02$; using the period-Wesenheit relation in two colors the distance modulus is $(m-M)_0=17.45 \pm 0.07$ corresponding to a distance of 30.9 Kpc. The observations show no signs of populations that are significantly younger than the $13$~Gyr stars. The width of the red giant branch does not allow for a spread in [Fe/H] greater than $\sigma = 0.05$ dex, and there is no photometric evidence for widened or parallel sequences. The $V, c_{UBI}$ pseudo-color magnitude diagram shows a bifurcation of the red giant branch that by analogy with other clusters is interpreted as being due to differing spectral signatures of the first (75\%) and second (25\%) generations of stars whose age difference is close enough that main sequence turnoffs in the color-magnitude diagram are unresolved. The cluster main sequence is visible against the background out to a radial distance of $\sim17$ arcmin. We conclude that NGC 5824 appears to be a classical Oosterhoff Type II globular cluster, without overt signs of being a remnant of a now-disrupted dwarf galaxy.Comment: 26 pages, 15 figures, 4 tables, accepted for publication in Astronomical Journa

Constraints on the Formation of the Globular Cluster IC 4499 from Multi-Wavelength Photometry

We present new multiband photometry for the Galactic globular cluster IC 4499 extending well past the main sequence turn-off in the U, B, V, R, I, and DDO51 bands. This photometry is used to determine that IC4499 has an age of 12 pm 1 Gyr and a cluster reddening of E(B-V) = 0.22 pm 0.02. Hence, IC 4499 is coeval with the majority of Galactic GCs, in contrast to suggestions of a younger age. The density profile of the cluster is observed to not flatten out to at least r~800 arcsec, implying that either the tidal radius of this cluster is larger than previously estimated, or that IC 4499 is surrounded by a halo. Unlike the situation in some other, more massive, globular clusters, no anomalous color spreads in the UV are detected among the red giant branch stars. The small uncertainties in our photometry should allow the detection of such signatures apparently associated with variations of light elements within the cluster, suggesting that IC 4499 consists of a single stellar population.Comment: accepted to MNRA

Chemical abundances in a high-velocity RR Lyrae star near the bulge

Low-mass variable high-velocity stars are interesting study cases for many aspects of Galactic structure and evolution. Until recently, the only known high- or hyper-velocity stars were young stars thought to originate from the Galactic center. Wide-area surveys such as APOGEE and BRAVA have found several low-mass stars in the bulge with Galactic rest-frame velocities higher than 350 km s-1. In this study we present the first abundance analysis of a low-mass RR Lyrae star that is located close to the Galactic bulge, with a space motion of ~–400 km s-1. Using medium-resolution spectra, we derived abundances (including upper limits) of 11 elements. These allowed us to chemically tag the star and discuss its origin, although our derived abundances and metallicity, at [Fe/H] =−0.9 dex, do not point toward one unambiguous answer. Based on the chemical tagging, we cannot exclude that it originated in the bulge. However, its retrograde orbit and the derived abundances combined suggest that the star was accelerated from the outskirts of the inner (or even outer) halo during many-body interactions. Other possible origins include the bulge itself, or the star might have been stripped from a stellar cluster or the Sagittarius dwarf galaxy when it merged with the Milky Way

HEMICHOREA: AN UNUSUAL MANIFESTATION OF THYROTOXICOSIS

ABSTRACTChorea is usually associated with neurological diseases. However, it can also be seen in patients with systemic lupus erythematosus (SLE), rheumaticfever (Sydenham's chorea), polycythemia vera, and thyrotoxicosis. Here, we report an interesting case of hemichorea in a 32-year-old lady, whopresented with acute onset of jerky, non-repetitive involuntary movements of the left upper and lower limbs. After detailed evaluation, she was foundto have thyrotoxicosis. Thyroid Tc-scan showed diffuse uptake suggesting Grave's disease. A magnetic resonance imaging of the brain was normal.Other causes of chorea like SLE and rheumatic fever were excluded. She was started on carbimazole. On follow-up after 6 weeks of therapy, there wasthe complete disappearance of chorea, and her thyroid hormone levels were normal.Keywords: Extrapyramidal syndrome, Hyperthyroidism, Corpus striatum, Dancing movements

THORACIC EPIDURAL ABSCESS DUE TO COMMUNITY-ACQUIRED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS

ABSTRACTA spinal epidural abscess threatens the spinal cord or cauda equina by compression and also by vascular compromise. If left untreated, an expandingsuppurative infection in the spinal epidural space can impinge on the spinal cord, producing sensory symptoms and signs, motor dysfunction, andultimately paralysis, followed by death. Hence, early intervention undoubtedly improves the outcome. The authors report a case of a 27-year-oldfemale patient, who presented with paraplegia, and was found to have thoracic epidural abscess due to community-acquired methicillin-resistantStaphylococcus aureus.Keywords: Spinal cord, Cauda equina, Infection, Laminectomy, Drainage

Tubular Micro-Discectomy Under Local Epidural Anaesthesia: A Technical Note

Objective Day-care surgery maximizes utilization of healthcare and aids in early return to work. Minimally invasive spine surgery (MISS) under local epidural anesthesia is a step in this direction. The combination of minimal surgical trauma and nominal sedation results in quick recovery and early discharge. To present our experience of performing lumbar tubular micro-discectomy under local epidural anaesthesia. Methods A case report of 10patients operated for lumbar herniated discs under local epidural anaesthesia. The patients had radicular pain since a few months with MRI evidence of herniated nucleus pulposus and failure of 6 weeks of conservative trial before surgery. The outcomes were assessed with ODI, VAS and Mac-Nab criteria. Premedication with Dexmedetomidine, local infiltration of lignocaine and bupivacaine with bolus dose of fentanyl during root manipulation facilitated the execution of the procedure. Results All patients obtained dramatic pain relief postoperatively. The procedure was well tolerated except for the slight discomfort during varying degrees of nerve-root retraction. Patients were made to walk and oral diet allowed after an hour and discharge was within 24 hours of the procedure. The VAS improved from 8.4 to 2.3 and ODI from 58.2 to 22.8. Follow-up was at 1, 6, 12 and 24 weeks. No complications such as dural tear, nerve root injury etc. were seen. Conclusion Microtubular discectomy under local epidural anaesthesia is a feasible option in experienced hands. Apart from reducing the effects of general anaesthesia, it reduces the hospital stay and cost. It is an evolution of microtubular discectomy towards day care surgery

Florix, an index to assess plant species in floodplains for nature conservation – Developed and tested along the river Danube

Natural floodplains are ecosystems with a diverse mosaic of habitats and site conditions, but also highly threatened due to anthropogenic pressures. Plant species occur in all habitat types and can indicate their value for nature conservation. To improve sustainable management of rivers and floodplains, several indices such as the River Ecosystem Service Index (RESI) have been developed. However, there are so far no assessment schemes for the entire range of floodplain plants. The common assessment approaches like biological integrity, achievement rates or threatened species (Red list), applying to other species groups or other ecosystems, are not appropriate in floodplains. Legal obligations and the need to restore floodplains clearly call for an index assessing the ecological value in a reference area which can be combined with a 5-scale assessment in accordance to established assessments like RESI or the Water Framework Directive. Five typical characteristics describing vascular plants’ adaptation to floodplain habitats were identified. These can be derived from published data sets available for all species in Germany. We checked these indicators for multicollinearity and selected three of them: species number, hydrodynamic indicators, nature conservation indicators. Species number highly correlate with habitat indicators and geographic occurrence. For the selected three indicators we determined thresholds to group habitats and their indicator rate to five classes (very low to very high value for nature conservation). These thresholds are valid for the river Danube and for the habitat types scrutinized in this study. The Florix approach was sensitive in data sets testing active against former floodplains and protected against unprotected areas: For the entire reference region ‘Danube floodplain’, Florix values were higher in the active floodplain and in the protected areas. Only the habitat type ‘water bodies’ showed better scores for habitats in the former floodplain, for ‘softwood forests’ the status of being part of a protected area had no effect. Florix results were validated in two case studies differing in land use intensity. The region with dominant agricultural use showed significantly lower values than that with a higher portion of forests and grasslands. Florix can be used for a floristic conservation status assessment at single habitat level or for the entity of a study region in comparison to a reference region. It allows to identify main pressures and to complement a habitat-type based evaluation. To achieve higher comparability, we should strive for a generalized monitoring in Europe like it is common in aquatic ecosystem monitoring