Columbus State University is a public institution of higher learning located in Columbus, Georgia. Founded as Columbus College in 1958, the university was established and is administered by the Board of Regents of the University System of Georgia, and is fully accredited by the Commission on Colleges of the Southern Association of Colleges and Schools. Wikipedia.
Edwards Z.I.,Columbus State University |
Pagnotta A.,Louisiana State University |
Schaefer B.E.,Louisiana State University
Astrophysical Journal Letters | Year: 2012
Models for the progenitor systems of Type Ia supernovae can be divided into double-degenerate systems, which contain two white dwarfs, and single-degenerate systems, which contain one white dwarf plus one companion star (either a red giant, a subgiant, or a >1.16 M main-sequence star). The white dwarf is destroyed in the supernova explosion, but any non-degenerate companion remains intact. We present the results of a search for an ex-companion star in SNR 0519-69.0, located in the Large Magellanic Cloud, based on images taken with the Hubble Space Telescope with a limiting magnitude of V = 26.05. SNR 0519-69.0 is confidently known to be from a Type Ia supernova based on its light echoes and X-ray spectra. The geometric center of the remnant (based on the Hα and X-ray shell) is at 05:19:34.83, -69:02:06.92 (J2000). Accounting for the measurement uncertainties, the orbital velocity, and the kick velocity, any ex-companion star must be within 47 of this position at the 99.73% confidence level. This circle contains 27 main-sequence stars brighter than V = 22.7, any one of which could be the ex-companion star left over from a supersoft source progenitor system. The circle contains no post-main-sequence stars, and this rules out the possibility of all other published single-degenerate progenitor classes (including symbiotic stars, recurrent novae, helium donors, and the spin-up/spin-down models) for this particular supernova. The only remaining possibility is that SNR 0519-69.0 was formed from either a supersoft source or a double-degenerate progenitor system. © 2012. The American Astronomical Society. All rights reserved.
Watanabe F.,Columbus State University
Journal of neuropathology and experimental neurology | Year: 2013
Hereditary spastic paraplegias (HSPs) are characterized by progressive spasticity and weakness in the lower extremities that result from length-dependent central to peripheral axonal degeneration. Mutations in the non-imprinted Prader-Willi/Angelman syndrome locus 1 (NIPA1) transmembrane protein cause an autosomal dominant form of HSP (SPG6). Here, we report that transgenic (Tg) rats expressing a human NIPA1/SPG6 mutation in neurons (Thy1.2-hNIPA1) show marked early onset behavioral and electrophysiologic abnormalities. Detailed morphologic analyses reveal unique histopathologic findings, including the accumulation of tubulovesicular organelles with endosomal features that start at axonal and dendritic terminals, followed by multifocal vacuolar degeneration in both the CNS and peripheral nerves. In addition, the NIPA1 mutation in the spinal cord from older Tg rats results in an increase in bone morphogenetic protein type II receptor expression, suggesting that its degradation is impaired. This Thy1.2-hNIPA1 Tg rat model may serve as a valuable tool for understanding endosomal trafficking in the pathogenesis of a subgroup of HSP with an abnormal interaction with bone morphogenetic protein type II receptor, as well as for developing potential therapeutic strategies for diseases with axonal degeneration and similar pathogenetic mechanisms.
Matic G.T.,Columbus State University
Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association | Year: 2014
PURPOSE: This study aimed to determine the ability of patients to return to activity after medial patellofemoral ligament (MPFL) reconstruction or repair for patellar instability.METHODS: A systematic review was performed using multiple databases. Studies reporting outcomes with Tegner scores after repair or reconstruction of the MPFL were included. Surgical technique, Tegner scores, and episodes of recurrent patellar instability were recorded.RESULTS: Ten articles with a total of 402 patients were included. The mean preoperative Tegner score was 4.7 (2.9 to 7.5). The mean postoperative Tegner score was 5.8 (4.0 to 7.7). Forty-nine patients (12.2%) had a recurrent episode of instability, 11 of whom required additional corrective procedures. There was a statistically significant larger failure rate among those who underwent MPFL repair (26.9%) than those who underwent reconstruction (6.6%) or medial retinacular repair/plication (16.5%).CONCLUSIONS: Recurrent dislocation was higher in patients who underwent MPFL repair rather than reconstruction. However, repair and reconstruction had similar Tegner scores. Repair or reconstruction of the soft tissue structures contributing to patellofemoral instability is successful in returning patients to preinjury activity levels.LEVEL OF EVIDENCE: Level IV, systematic review of Level II, III, and IV studies. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
Hawthorne T.L.,Columbus State University |
Kwan M.-P.,Ohio State University
Geographical Journal | Year: 2012
Geographers play important roles in public health research, particularly in understanding healthcare accessibility, utilisation, and individual healthcare experiences. Most accessibility studies have benefited from the increased sophistication of geographic information systems (GIS). Some studies have been enhanced with semi-structured in-depth interviews to understand individual experiences of people as they access healthcare. However, few accessibility studies have explicitly utilised individual in-depth interview data in the construction of new GIS accessibility measures. Using mixed methods including GIS analysis and individual data from semi-structured in-depth interviews, we offer satisfaction-adjusted distance as a new way of conceptualising accessibility in GIS. Based on fieldwork in a predominantly lower-income community in Columbus, Ohio (USA), we find many residents felt neighbourhood healthcare facilities offered low-quality care, which suggested an added perceived distance as they attempt to access high-quality healthcare facilities. The satisfaction-adjusted distance measure accounts for the perceived distance some residents feel as they search for high-quality healthcare in lower-income urban neighbourhoods. In moving beyond conventional GIS and re-conceptualising accessibility in this way, we offer a more realistic portrayal of the issues lower-income urban residents face as they attempt to access high-quality healthcare facilities. The work has theoretical implications for conceptualising healthcare accessibility, advances the mixed-methodologies literature, and argues for a more equitable distribution of high-quality healthcare in urban neighbourhoods. © 2011 The Authors. The Geographical Journal © 2011 Royal Geographical Society (with the Institute of British Geographers).
Swenson N.G.,Michigan State University |
Anglada-Cordero P.,University of Puerto Rico at San Juan |
Barone J.A.,Columbus State University
Proceedings of the Royal Society B: Biological Sciences | Year: 2011
Explaining the mechanisms that produce the enormous diversity within and between tropical tree communities is a pressing challenge for plant community ecologists. Mechanistic hypotheses range from niche-based deterministic to dispersal-based stochastic models. Strong tests of these hypotheses require detailed information regarding the functional strategies of species. A few tropical studies to date have examined trait dispersion within individual forest plots using species trait means in order to ask whether coexisting species tend to be more or less functionally similar than expected given a null model. The present work takes an alternative approach by: (i) explicitly incorporating population-level trait variability; and (ii) quantifying the functional beta diversity in a series of 15 tropical forest plots arrayed along an elevational gradient. The results show a strong pattern of decay in community functional similarity with elevation. These observed patterns of functional beta diversity are shown to be highly nonrandom and support a deterministic model of tropical tree community assembly and turnover. © 2010 The Royal Society.