4,444 research outputs found

    Optimization of Mitochondrial Isolation Techniques for Intraspinal Transplantation Procedures

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    Background—Proper mitochondrial function is essential to maintain normal cellular bioenergetics and ionic homeostasis. In instances of severe tissue damage, such as traumatic brain and spinal cord injury, mitochondria become damaged and unregulated leading to cell death. The relatively unexplored field of mitochondrial transplantation following neurotrauma is based on the theory that replacing damaged mitochondria with exogenous respiratory-competent mitochondria can restore overall tissue bioenergetics. New Method—We optimized techniques in vitro to prepare suspensions of isolated mitochondria for transplantation in vivo. Mitochondria isolated from cell culture were genetically labeled with turbo-green fluorescent protein (tGFP) for imaging and tracking purposes in vitro and in vivo. Results—We used time-lapse confocal imaging to reveal the incorporation of exogenous fluorescently-tagged mitochondria into PC-12 cells after brief co-incubation. Further, we show that mitochondria can be injected into the spinal cord with immunohistochemical evidence of host cellular uptake within 24 hours. Comparison to Existing Methods—Our methods utilize transgenic fluorescent labeling of mitochondria for a nontoxic and photostable alternative to other labeling methods. Substrate addition to isolated mitochondria helped to restore state III respiration at room temperature prior to transplantation. These experiments delineate refined methods to use transgenic cell lines for the purpose of isolating well coupled mitochondria that have a permanent fluorescent label that allows real time tracking of transplanted mitochondria in vitro, as well as imaging in situ. Conclusions—These techniques lay the foundation for testing the potential therapeutic effects of mitochondrial transplantation following spinal cord injury and other animal models of neurotrauma

    Editorial: The History and Evolution of the Journal of Sorority and Fraternity Life Research and Practice

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    Individuals involved in the founding of the Oracle: The Research Journal of the Association of Fraternity/Sorority Advisors (Oracle), former Oracle editors and Adam M. McCready, Editor of Journal of Sorority and Fraternity Life Research and Practice share the history and evolution of the journal over the past two decades

    Plasma Spectroscopy of Titanium Monoxide for Characterization of Laser Ablation

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    Ablation of titanium wafers in air is accomplished with 60 ”s pulsed, 2.94 ”m laser radiation. Titanium monoxide spectra are measured in the wavelength range of 500 nm to 750 nm, and molecular signatures include bands of the C3 Δ → X3 Δ α, B3 Π → X3 Δ Îł\u27, and A3 Ί → X3 Δ Îł transitions. The spatially and temporally averaged spectra appear to be in qualitative agreement with previous temporally resolved studies that employed shorter wavelengths and shorter pulse durations than utilized in this work. The background signals in the current study are possibly due to particulate content in the plume. A chemical kinetic model of the plume is being developed that will be coupled to a diatomic emission model in order to extract a molecular temperature from the observed spectra

    A Candidate Young Massive Planet in Orbit around the Classical T Tauri Star CI Tau

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    The ~2 Myr old classical T Tauri star CI Tau shows periodic variability in its radial velocity (RV) variations measured at infrared (IR) and optical wavelengths. We find that these observations are consistent with a massive planet in a ~9-day period orbit. These results are based on 71 IR RV measurements of this system obtained over 5 years, and on 26 optical RV measurements obtained over 9 years. CI Tau was also observed photometrically in the optical on 34 nights over ~one month in 2012. The optical RV data alone are inadequate to identify an orbital period, likely the result of star spot and activity induced noise for this relatively small dataset. The infrared RV measurements reveal significant periodicity at ~9 days. In addition, the full set of optical and IR RV measurements taken together phase coherently and with equal amplitudes to the ~9 day period. Periodic radial velocity signals can in principle be produced by cool spots, hot spots, and reflection of the stellar spectrum off the inner disk, in addition to resulting from a planetary companion. We have considered each of these and find the planet hypothesis most consistent with the data. The radial velocity amplitude yields an Msin(i) of ~8.1 M_Jup; in conjunction with a 1.3 mm continuum emission measurement of the circumstellar disk inclination from the literature, we find a planet mass of ~11.3 M_Jup, assuming alignment of the planetary orbit with the disk.Comment: 61 pages, 13 figures, accepted for publication in The Astrophysical Journa

    Structure–function relationships explain CTCF zinc finger mutation phenotypes in cancer

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    CCCTC-binding factor (CTCF) plays fundamental roles in transcriptional regulation and chromatin architecture maintenance. CTCF is also a tumour suppressor frequently mutated in cancer, however, the structural and functional impact of mutations have not been examined. We performed molecular and structural characterisation of five cancer-specific CTCF missense zinc finger (ZF) mutations occurring within key intra- and inter-ZF residues. Functional characterisation of CTCF ZF mutations revealed a complete (L309P, R339W, R377H) or intermediate (R339Q) abrogation as well as an enhancement (G420D) of the anti-proliferative effects of CTCF. DNA binding at select sites was disrupted and transcriptional regulatory activities abrogated. Molecular docking and molecular dynamics confirmed that mutations in residues specifically contacting DNA bases or backbone exhibited loss of DNA binding. However, R339Q and G420D were stabilised by the formation of new primary DNA bonds, contributing to gain-of-function. Our data confirm that a spectrum of loss-, change- and gain-of-function impacts on CTCF zinc fingers are observed in cell growth regulation and gene regulatory activities. Hence, diverse cellular phenotypes of mutant CTCF are clearly explained by examining structure–function relationships

    The Next Generation Virgo Cluster Survey - Infrared (NGVS-IR): I. A new Near-UV/Optical/Near-IR Globular Cluster selection tool

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    The NGVS-IR project (Next Generation Virgo Survey - Infrared) is a contiguous near-infrared imaging survey of the Virgo cluster of galaxies. It complements the optical wide-field survey of Virgo (NGVS). The current state of NGVS-IR consists of Ks-band imaging of 4 deg^2 centered on M87, and J and Ks-band imaging of 16 deg^2 covering the region between M49 and M87. In this paper, we present the observations of the central 4 deg^2 centered on Virgo's core region. The data were acquired with WIRCam on the Canada-France-Hawaii Telescope and the total integration time was 41 hours distributed in 34 contiguous tiles. A survey-specific strategy was designed to account for extended galaxies while still measuring accurate sky brightness within the survey area. The average 5\sigma limiting magnitude is Ks=24.4 AB mag and the 50% completeness limit is Ks=23.75 AB mag for point source detections, when using only images with better than 0.7" seeing (median seeing 0.54"). Star clusters are marginally resolved in these image stacks, and Virgo galaxies with \mu_Ks=24.4 AB mag arcsec^-2 are detected. Combining the Ks data with optical and ultraviolet data, we build the uiK color-color diagram which allows a very clean color-based selection of globular clusters in Virgo. This diagnostic plot will provide reliable globular cluster candidates for spectroscopic follow-up campaigns needed to continue the exploration of Virgo's photometric and kinematic sub-structures, and will help the design of future searches for globular clusters in extragalactic systems. Equipped with this powerful new tool, future NGVS-IR investigations based on the uiK diagram will address the mapping and analysis of extended structures and compact stellar systems in and around Virgo galaxies.Comment: 23 pages, 18 figures. Accepted for publication in ApJ

    The Diverse Properties of the Most Ultraviolet Luminous Galaxies Discovered by the Galaxy Evolution Explorer

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    We report on the properties of a sample of ultraviolet luminous galaxies (UVLGs) selected by matching the Galaxy Evolution Explorer (GALEX) Surveys with the Sloan Digital Sky Survey Third Data Release. Out of 25362 galaxies between 0.02x10^10 L_solar at 1530 Angstroms (observed wavelength). The properties of this population are well correlated with ultraviolet surface brightness. We find that the galaxies with low UV surface brightness are primarily large spiral systems with a mixture of old and young stellar populations, while the high surface brightness galaxies consist primarily of compact starburst systems. In terms of the behavior of surface brightness with luminosity, size with luminosity, the mass-metallicity relation, and other parameters, the compact UVLGs clearly depart from the trends established by the full sample of galaxies. The subset of compact UVLGs with the highest surface brightness (``supercompact UVLGs'') have characteristics that are remarkably similar to Lyman Break Galaxies at higher redshift. They are much more luminous than typical local ultraviolet-bright starburst galaxies and blue compact dwarf galaxies. They have metallicities that are systematically lower than normal galaxies of the same stellar mass, indicating that they are less chemically evolved. In all these respects, they are the best local analogs for Lyman Break Galaxies.Comment: Fixed error in ObjID column of Table 1. 30 pages, 12 figures. Accepted for the GALEX special issue of ApJS. Abstract abridge

    Detection, identification and characterization of extended-spectrum beta-lactamases producing Enterobacteriaceae in wastewater and salads marketed in Ouagadougou, Burkina Faso

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    Extended spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE) represent a threat for failure of empirical antibiotic therapy and are associated with high mortality, morbidity and expenses. The aims of this study was to determine the prevalence of ESBL-PE and multidrug resistant enterobacteria (MDR), enterobacteria profil, investigate the associated resistance in wastewater and salads. After wastewater and salad sampling, enterobacteria was isoled on (EMB + 4ÎŒg / L cefotaxim). The stains of Enterobacteriaceae were identified by using biochemical methods and confirmed as ESBL by double-disc synergy test (amoxicillin/clavulanic acid with cefotaxime 30 ÎŒg, ceftazidime 30 ÎŒg and ceftriaxone 30 ÎŒg). Finally, the associated resistance was investigated by testing the susceptibility of the strains by the disc diffusion method. Global prevalence of ESBL-PE was 53.92% (95% CI: 48,2-59,5) (153/293), 61.11% from wastewater and 42.47% from salads. Major ESBL-E was Escherichia coli (73.44%), followed by Klebsiella pneumoniae (21.88%). Resistance to the aminoglycoside , fluroquinolonones and sulfonamides classes were dominant, observed in 53,83%, 93,86% and 98,95% of the isolates, respectively. The frequence of MDR was hight to channel1 (32,40%) and channel2 (26,26%). This study reports very worrying results. There is an urgent need to develop measures to monitor the spread of these multidrug-resistant strains.Keywords: Wastewater, ESBL-PE, Salads, Ouagadougou
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