1,885 research outputs found
The Due Process of Military Commissions
The University Archives has determined that this item is of continuing value to OSU's history.Retired Army Gen. John D. Altenburg, Jr. was
appointed by Secretary of Defense Donald Rumsfeld as the head of the Office of the Appointing Authority. His duties include overseeing the military tribunals of the terrorism suspects held at Guantanamo Bay, Cuba.Ohio State University. Mershon Center for International Security Studiesweb page announcement, phot
Increased Filamentous Growth of Candida albicans in Simulated Microgravity
Knowledge of simulated microgravity (SMG)-induced changes in the pathogenicity of microorganisms is important for success of long-term spaceflight. In a previous study using the high aspect ratio vessel bioreactor, we showed that the yeast species Saccharomyces cerevisiae underwent a significant phenotypic response when grown in modeled microgravity, which was reflected in the analysis of gene expression profiles. In this study, we establish that Candida albicans responds to SMG in a similar fashion, demonstrating that there is a conserved response among yeast to this environmental stress. We also report that the growth of C. albicans in SMG results in a morphogenic switch that is consistent with enhanced pathogenicity. Specifically, we observed an increase in filamentous forms of the organism and accompanying changes in the expression of two genes associated with the yeast-hyphal transition. The morphological response may have significant implications for astronauts’ safety, as the fungal pathogen may become more virulent during spaceflight
Atomic hydrogen, star formation and feedback in the lowest mass Blue Compact Dwarf galaxies
We present the results from a search for HI emission from a sample of newly
discovered dwarf galaxies in the M81 group. HI is detected in three galaxies,
all of which are classified as BCDs. The HI masses of these galaxies are ~ 10^6
M_sun, making these some of the lowest mass BCDs known. For these three
galaxies FUV images (from GALEX) and H-alpha images (from the Russian 6m BTA
telescope) are available.The H-alpha emission is very faint, and, in principle
could be produced by a single O star. Further, in all cases we find offsets
between the peak of the FUV emission and that of the H-alpha emission. Offsets
between the most recent sites of star formation (i.e. those traced by H-alpha)
and the older sites (i.e. those traced by FUV) would be natural if the star
formation is stochastic. In spite of the expectation that the effects of
mechanical feedback from star formation would be most directly seen in the
smallest galaxies with low gravitational potentials, we only see tentative
evidence of outflowing HI gas associated with the star forming region in one of
the galaxies.Comment: 9 pages, 5 figures, 5 tables. Accepted for publication in MNRAS. The
definitive version is available at www.blackwell-synergy.co
Eradication treatment for Pseudomonas aeruginosa infection in adults with bronchiectasis:a systematic review and meta-analysis
INTRODUCTION: Pseudomonas aeruginosa is the most commonly isolated pathogen in bronchiectasis and is associated with worse outcomes. Eradication treatment is recommended by guidelines, but the evidence base is limited. The expected success rate of eradication in clinical practice is not known.METHODS: We conducted a systematic review and meta-analysis according to Meta-Analysis of Observational Studies in Epidemiology guidelines. PubMed, Embase, the Cochrane Database of Systematic Reviews and Clinicaltrials.gov were searched for studies investigating P. aeruginosa eradication treatment using antibiotics (systemic or inhaled) in patients with bronchiectasis. The primary outcome was the percentage of patients negative for P. aeruginosa at 12 months after eradication treatment. Cystic fibrosis was excluded.RESULTS: Six observational studies including 289 patients were included in the meta-analysis. Our meta-analysis found a 12-month P. aeruginosa eradication rate of 40% (95% CI 34-45%; p<0.00001), with no significant heterogeneity (I2=0%). Combined systemic and inhaled antibiotic treatment was associated with a higher eradication rate (48%, 95% CI 41-55%) than systemic antibiotics alone (27%, 13-45%).CONCLUSION: Eradication treatment in bronchiectasis results in eradication of P. aeruginosa from sputum in ∼40% of cases at 12 months. Combined systemic and inhaled antibiotics achieve higher eradication rates than systemic antibiotics alone.</p
Yeast genomic expression patterns in response to low-shear modeled microgravity
The low-shear microgravity environment, modeled by rotating suspension culture bioreactors called high aspect ratio vessels (HARVs), allows investigation in ground-based studies of the effects of microgravity on eukaryotic cells and provides insights into the impact of space flight on cellular physiology. We have previously demonstrated that low-shear modeled microgravity (LSMMG) causes significant phenotypic changes of a select group of Saccharomyces cerevisiae genes associated with the establishment of cell polarity, bipolar budding, and cell separation. However, the mechanisms cells utilize to sense and respond to microgravity and the fundamental gene expression changes that occur are largely unknown. In this study, we examined the global transcriptional response of yeast cells grown under LSMMG conditions using DNA microarray analysis in order to determine if exposure to LSMMG results in changes in gene expression. LSMMG differentially changed the expression of a significant number of genes (1372) when yeast cells were cultured for either five generations or twenty-five generations in HARVs, as compared to cells grown under identical conditions in normal gravity. We identified genes in cell wall integrity signaling pathways containing MAP kinase cascades that may provide clues to novel physiological responses of eukaryotic cells to the external stress of a low-shear modeled microgravity environment. A comparison of the microgravity response to other environmental stress response (ESR) genes showed that 26% of the genes that respond significantly to LSMMG are involved in a general environmental stress response, while 74% of the genes may represent a unique transcriptional response to microgravity. In addition, we found changes in genes involved in budding, cell polarity establishment, and cell separation that validate our hypothesis that phenotypic changes observed in cells grown in microgravity are reflected in genome-wide changes. This study documents a considerable response to yeast cell growth in low-shear modeled microgravity that is evident, at least in part, by changes in gene expression. Notably, we identified genes that are involved in cell signaling pathways that allow cells to detect environmental changes, to respond within the cell, and to change accordingly, as well as genes of unknown function that may have a unique transcriptional response to microgravity. We also uncovered significant changes in the expression of many genes involved in cell polarization and bud formation that correlate well with the phenotypic effects observed in yeast cells when grown under similar conditions. These results are noteworthy as they have implications for human space flight
Small Bites: Star formation recipes in extreme dwarfs
We study the relationship between the gas column density (Sigma_HI) and the
star formation rate surface density (Sigma_SFR) for a sample of extremely small
(M_B ~ -13, Delta V_50 ~ 30 km/s) dwarf irregular galaxies. We find a clear
stochasticity in the relation between the gas column density and star
formation. All gas with Sigma_HI >~ 10 M_sun/pc^2 has some ongoing star
formation, but the fraction of gas with ongoing star formation decreases as the
gas column density decreases, and falls to about 50% at Sigma_HI ~ 3
M_sun/pc^2. Further, even for the most dense gas, the star formation efficiency
is at least a factor of ~ 2 smaller than typical of star forming regions in
spirals. We also find that the ratio of H-alpha emission to FUV emission
increases with increasing gas column density. This is unlikely to be due to
increasing dust extinction because the required dust to gas ratios are too
high. We suggest instead that this correlation arises because massive (i.e.
H-alpha producing) stars are formed preferentially in regions with high gas
density.Comment: 5 pages, 5 figures, 1 table. Accepted for publication in MNRAS
Letters. The definitive version is available at www.blackwell- synergy.co
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