939 research outputs found

    Patterns of gene expression in schistosomes: localization by whole mount in situ hybridization

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    rom the identification of genes to the characterization of their functions and interactions. Developmental biologists have long used whole mount in situ hybridization (WISH) to determine gene expression patterns, as a vital tool for formulating and testing hypotheses about function. This paper describes the application of WISH to the study of gene expression in larval and adult schistosomes. Fixed worms were permeablized by proteinase K treatment for hybridization with digoxygenin-labelled RNA probes, with binding being detected by alkaline phosphatase-coupled anti-digoxygenin antibodies, and BM Purple substrate. Discrete staining patterns for the transcripts of the molecules Sm29, cathepsin L, antigen 10.3 and chorion were observed in the tegument cell bodies, gut epithelium, oesophageal gland and vitelline lobules, respectively, of adult worms. Transcripts of the molecules SGTP4, GP18-22 and cathepsin L were localized to tegument cell bodies and embryonic gut, respectively, of lung schistosomula. We also showed that Fast Red TR fluorescent substrate can refine the pattern of localization permitting use of confocal microscopy. We believe that method of WISH will find broad application, in synergy with other emerging post-genomic techniques, such as RNA interference, to studies focused at increasing our molecular understanding of schistosomes

    Development of a Novel Biological Intervertebral Disc Scaffold

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    Back pain is a major public health issue in our society, and is strongly correlated with the degeneration of intervertebral discs (IVDs). Current therapies are conservative or surgical, and no attempt to regenerate the IVD. The first goal of our project is to create a fully decellularized bovine caudal IVD to be used as a scaffold on which to seed adult human stem cells in an attempt to engineer a healthy, replacement IVD for patients suffering from IVD degeneration and lower back pain. The goal of decellularization is to eliminate DNA content while retaining glycosaminoglycan (GAG) content. Eliminating DNA content will prevent a foreign body response by the host\u27s immune system once the IVD is implanted. GAG is responsible for forming interfibrillar bridges with collagen fibrils and thus assisting in resisting compressive and tensile forces. By retaining GAG content in our decellularized IVDs we will maintain structural integrity of the extracellular matrix. The IVDs closest to the base of the bovine tail were targeted, because they are similar in size and biochemistry to the human IVD. We use a mix of conventional methods including freeze thaw, sonication and agitation in a solution of sodium dodecyl sulfate (SDS) and ethylene diamine tetraacetic acid (EDTA). After decellularization, half of each IVD was placed in a tissue cassette and put formalin in preparation for histological analysis, and the other half was frozen prior to biochemical analysis (DMMB and PicoGreen assay). Our results thus far are promising in eliminating DNA content but show we have a large room for improvement in retaining GAG content

    The Cost of Blindness in the Republic of Ireland 2010-2020

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    Aims. To estimate the prevalence of blindness in the Republic of Ireland and the associated financial and total economic cost between 2010 and 2020. Methods. Estimates for the prevalence of blindness in the Republic of Ireland were based on blindness registration data from the National Council for the Blind of Ireland. Estimates for the financial and total economic cost of blindness were based on the sum of direct and indirect healthcare and nonhealthcare costs. Results. We estimate that there were 12,995 blind individuals in Ireland in 2010 and in 2020 there will be 17,997. We estimate that the financial and total economic costs of blindness in the Republic of Ireland in 2010 were €276.6 million and €809 million, respectively, and will increase in 2020 to €367 million and €1.1 billion, respectively. Conclusions. Here, ninety-eight percent of the cost of blindness is borne by the Departments of Social Protection and Finance and not by the Department of Health as might initially be expected. Cost of illness studies should play a role in public policy making as they help to quantify the indirect or “hidden” costs of disability and so help to reveal the true cost of illness

    Complex magnetic topology and strong differential rotation on the low-mass T Tauri star V2247 Oph

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    From observations collected with the ESPaDOnS spectropolarimeter at the Canada-France-Hawaii Telescope, we report the detection of Zeeman signatures on the low-mass classical TTauri star (cTTS) V2247Oph. Profile distortions and circular polarisation signatures detected in photospheric lines can be interpreted as caused by cool spots and magnetic regions at the surface of the star. The large-scale field is of moderate strength and highly complex; moreover, both the spot distribution and the magnetic field show significant variability on a timescale of only one week, as a likely result of strong differential rotation. Both properties make V2247Oph very different from the (more massive) prototypical cTTS BPTau; we speculate that this difference reflects the lower mass of V2247Oph. During our observations, V2247Oph was in a low-accretion state, with emission lines showing only weak levels of circular polarisation; we nevertheless find that excess emission apparently concentrates in a mid-latitude region of strong radial field, suggesting that it is the footpoint of an accretion funnel. The weaker and more complex field that we report on V2247Oph may share similarities with those of very-low-mass late-M dwarfs and potentially explain why low-mass cTTSs rotate on average faster than intermediate mass ones. These surprising results need confirmation from new independent data sets on V2247Oph and other similar low-mass cTTSs.Comment: MNRAS (in press) - 12 pages, 9 figure

    Characterization of Temporal and Spatial Variability of Turbidity in the Upper Chattahoochee River

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    Proceedings of the 1997 Georgia Water Resources Conference, March 20-22, 1997, Athens, Georgia.Our objective is to develop the information necessary for establishing a regulatory basis for sediment control. We present sediment data at four USGS monitoring stations in the Upper Chattahoochee River Watershed. The data show that TSS is a strong function of discharge. A unique relationship between TSS and discharge is found for all stations when the discharge is normalized by its long-term mean. With this regional relationship, we can establish a baseline for comparing watersheds as a function of discharge.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602 with partial funding provided by the U.S. Department of Interior, Geological Survey, through the Georgia Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors

    Variable X-ray emission from the accretion shock in the classical T Tauri star V2129 Ophiuchi

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    Context. The soft X-ray emission from high density plasma observed in several CTTS is usually associated with the accretion process. However, it is still unclear whether this high density “cool” plasma is heated in the accretion shock, or if it is coronal plasma fed or modified by the accretion process. Aims. We conducted a coordinated quasi-simultaneous optical and X-ray observing campaign of the CTTS V2129 Oph. In this paper, we analyze Chandra grating spectrometer data and attempt to correlate the observed X-ray emitting plasma components with the characteristics of the accretion process and the stellar magnetic field constrained by simultaneous optical observations. Methods. We analyze a 200 ks Chandra/HETGS observation, subdivided into two 100 ks segments, of the CTTS V2129 Oph. For the two observing segments corresponding to two different phases within one stellar rotation, we measure the density of the cool plasma component and the emission measure distribution. Results. The X-ray emitting plasma covers a wide range of temperatures: from 2 up to 34 MK. The cool plasma component of V2129 Oph (T ≈ 3−4 MK) varies between the two segments of the Chandra observation: during the first observing segment high density plasma (log N_c = 12.1_(-1.1)^(+0.6)) with high EM at ~3−4 MK is present, whereas, during the second segment, this plasma component has lower EM and lower density (log N_e 3 R_⋆). Conclusions. Our observation provides additional confirmation that the dense cool plasma at a few MK in CTTS is material heated in the accretion shock. The variability of this cool plasma component on V2129 Oph may be explained in terms of X-rays emitted in the accretion shock and seen with different viewing angles at the two rotational phases probed by our observation. In particular, during the first time interval a direct view of the shock region is possible, while, during the second, the accretion funnel itself intersects the line of sight to the shock region, preventing us from observing the accretion-driven X-rays

    Impact of Baseline Magnetic Resonance Imaging on Neurologic, Functional, and Safety Outcomes in Patients With Acute Traumatic Spinal Cord Injury

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    Study Design: Systematic review. Objective: To perform a systematic review to evaluate the utility of magnetic resonance imaging (MRI) in patients with acute spinal cord injury (SCI). Methods: An electronic search of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar was conducted for literature published through May 12, 2015, to answer key questions associated with the use of MRI in patients with acute SCI. Results: The literature search yielded 796 potentially relevant citations, 8 of which were included in this review. One study used MRI in a protocol to decide on early surgical decompression. The MRI-protocol group showed improved outcomes; however, the quality of evidence was deemed very low due to selection bias. Seven studies reported MRI predictors of neurologic or functional outcomes. There was moderate-quality evidence that longer intramedullary hemorrhage (2 studies) and low-quality evidence that smaller spinal canal diameter at the location of maximal spinal cord compression and the presence of cord swelling are associated with poor neurologic recovery. There was moderate-quality evidence that clinical outcomes are not predicted by SCI lesion length and the presence of cord edema. Conclusions: Certain MRI characteristics appear to be predictive of outcomes in acute SCI, including length of intramedullary hemorrhage (moderate-quality evidence), canal diameter at maximal spinal cord compression (low-quality evidence), and spinal cord swelling (low-quality evidence). Other imaging features were either inconsistently (presence of hemorrhage, maximal canal compromise, and edema length) or not associated with outcomes. The paucity of literature highlights the need for well-designed prospective studies. © 2017, © The Author(s) 2017

    Dynamo Processes in the T Tauri star V410 Tau

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    We present new brightness and magnetic images of the weak-line T Tauri star V410 Tau, made using data from the NARVAL spectropolarimeter at Telescope Bernard Lyot (TBL). The brightness image shows a large polar spot and significant spot coverage at lower latitudes. The magnetic maps show a field that is predominantly dipolar and non-axisymmetric with a strong azimuthal component. The field is 50% poloidal and 50% toroidal, and there is very little differential rotation apparent from the magnetic images. A photometric monitoring campaign on this star has previously revealed V-band variability of up to 0.6 magnitudes but in 2009 the lightcurve is much flatter. The Doppler image presented here is consistent with this low variability. Calculating the flux predicted by the mapped spot distribution gives an peak-to-peak variability of 0.04 magnitudes. The reduction in the amplitude of the lightcurve, compared with previous observations, appears to be related to a change in the distribution of the spots, rather than the number or area. This paper is the first from a Zeeman-Doppler imaging campaign being carried out on V410 Tau between 2009-2012 at TBL. During this time it is expected that the lightcurve will return to a high amplitude state, allowing us to ascertain whether the photometric changes are accompanied by a change in the magnetic field topology.Comment: 12 pages, 11 figures, accepted by MNRA
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