16 research outputs found

    Cometary ion drift energy and temperature at comet 67P-Churyumov/Gerasimeko

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    The Ion Composition Analyzer (ICA) on the Rosetta spacecraft observed both the solar wind and the cometary ionosphere around comet 67P/Churyumov-Gerasimenko for nearly two years. However, observations of low energy cometary ions were affected by a highly negative spacecraft potential, and the ICA ion density estimates were often much lower than plasma densities found by other instruments. Since the low energy cometary ions are often the highest density population in the plasma environment, it is nonetheless desirable to understand their properties. To do so, we select ICA data with densities comparable to those of Rosetta's Langmuir Probe (LAP)/Mutual Impedance Probe throughout the mission. We then correct the cometary ion energy distribution of each energy-angle scan for spacecraft potential and fit a drifting Maxwell-Boltzmann distribution, which gives an estimate of the drift energy and temperature for 3521 scans. The resulting drift energy is generally between 11--18 eV and the temperature between 0.5--1 eV. The drift energy shows good agreement with published ion flow speeds from LAP during the same time period and is much higher than the cometary neutral speed. We see additional higher energy cometary ions in the spectra closest to perihelion, which can either be a second Maxwellian or a kappa distribution. The energy and temperature are negatively correlated with heliocentric distance, but the slope of the change is small. It cannot be quantitatively determined whether this trend is primarily due to heliocentric distance or spacecraft distance to the comet, which increased with decreasing heliocentric distance.Comment: 9 pages, 10 figure

    Escherichia coli as Reservoir for Macrolide Resistance Genes

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    The plasmid-borne mph(A) gene that confers resistance to azithromycin and has recently emerged in Shigella sonnei is present in multidrug- and non–multidrug-resistant Escherichia coli isolates from 4 continents. Further spread of mph(A) to Shigella and Salmonella spp. may be expected

    La maladie du charbon et son agent étiologique Bacillus anthracis (de ses origines à son développement comme arme biologique)

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    CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

    La poliomyélite, une maladie en voie d'éradication

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    CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

    La recrudescence de la rougeole

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    CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

    La lèpre (maladie d'hier encore d'actualité)

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    CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

    Rôle des bactéries dans les maladies parodontales

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    CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

    Les papillomavirus humains (dépistage et prévention du cancer du col de l'utérus)

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    CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

    Clostridium perfringens et pathologies ovines (une participation à la mise en évidence du récepteur de la toxine epsilon)

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    CAEN-BU Médecine pharmacie (141182102) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF
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