84 research outputs found

    Altitude dependence of nightside Martian suprathermal electron depletions as revealed by MAVEN observations

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    The MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft is providing new detailed observations of the Martian ionosphere thanks to its unique orbital coverage and instrument suite. During most periapsis passages on the nightside ionosphere suprathermal electron depletions were detected. A simple criterion was implemented to identify the 1742 depletions observed from 16 November 2014 to 28 February 2015. A statistical analysis reveals that the main ion and electron populations within the depletions are surprisingly constant in time and altitude. Absorption by CO2 is the main loss process for suprathermal electrons, and electrons that strongly peaked around 6 eV are resulting from this interaction. The observation of depletions appears however highly dependent on altitude. Depletions are mainly located above strong crustal magnetic sources above 170 km, whereas the depletions observed for the first time below 170 km are globally scattered onto the Martian surface with no particular dependence on crustal fields

    Upper limits for undetected trace species in the stratosphere of Titan

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    In this paper we describe a first quantitative search for several molecules in Titan's stratosphere in Cassini CIRS infrared spectra. These are: ammonia (NH3), methanol (CH3OH), formaldehyde (H2CO), and acetonitrile (CH3CN), all of which are predicted by photochemical models but only the last of which observed, and not in the infrared. We find non-detections in all cases, but derive upper limits on the abundances from low-noise observations at 25{\deg}S and 75{\deg}N. Comparing these constraints to model predictions, we conclude that CIRS is highly unlikely to see NH3 or CH3OH emissions. However, CH3CN and H2CO are closer to CIRS detectability, and we suggest ways in which the sensitivity threshold may be lowered towards this goal.Comment: 11 pages plus 6 figure file

    SERENA:Particle Instrument Suite for Determining the Sun-Mercury Interaction from BepiColombo

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    International audienceThe ESA-JAXA BepiColombo mission to Mercury will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric particle dynamics at Mercury as well as their interactions with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for ion and neutral particle detection aboard the MPO. It comprises four independent sensors: ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA is managed by a System Control Unit located inside the ELENA box. In the present paper the scientific goals of this suite are described, and then the four units are detailed, as well as their major features and calibration results. Finally, the SERENA operational activities are shown during the orbital path around Mercury, with also some reference to the activities planned during the long cruise phase

    Correction to: SERENA: Particle Instrument Suite for Determining the Sun-Mercury Interaction from BepiColombo

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    International audienc

    The Effect of DNA-Dependent Protein Kinase on Adeno-Associated Virus Replication

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    BACKGROUND: DNA-dependent protein kinase (DNA-PK) is a DNA repair enzyme and plays an important role in determining the molecular fate of the rAAV genome. However, the effect this cellular enzyme on rAAV DNA replication remains elusive. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we characterized the roles of DNA-PK on recombinant adeno-associated virus DNA replication. Inhibition of DNA-PK by a DNA-PK inhibitor or siRNA targeting DNA-PKcs significantly decreased replication of AAV in MO59K and 293 cells. Southern blot analysis showed that replicated rAAV DNA formed head-to-head or tail-to-tail junctions. The head-to-tail junction was low or undetectable suggesting AAV-ITR self-priming is the major mechanism for rAAV DNA replication. In an in vitro replication assay, anti-Ku80 antibody strongly inhibited rAAV replication, while anti-Ku70 antibody moderately decreased rAAV replication. Similarly, when Ku heterodimer (Ku70/80) was depleted, less replicated rAAV DNA were detected. Finally, we showed that AAV-ITRs directly interacted with Ku proteins. CONCLUSION/SIGNIFICANCE: Collectively, our results showed that that DNA-PK enhances rAAV replication through the interaction of Ku proteins and AAV-ITRs

    Treatment of male and female precocious puberty (PP) by monthly injections of a continuous release preparation of D-Trp-6-LH-RH

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    Successful treatment of PP by daily subcutaneous (SC) administration of the LH-RH agonist D-Trp-6-LH-RH (Trp6) was reported (Kauli et al., ESPE 1983). After demonstration of its efficiency and innocuity in dogs, a long acting preparation designed for releasing continuously 100 μg Trp6 per 24 h, was given intramuscularly to 3 boys and 3 girls with PP, aged 3 to 8 years. 3 mg Trp6 were injected every 28 days, cyproterone acetate being associated during the first week. In boys testosterone levels (ng/ml) decreased from 2.2-5 to 0.1-0.2 within 2 months. Testis volume was unaffected in 1, decreased slighty in 2. In girls estradiol levels (pg/ml) decreased from 40-100 to 0-40 within 2 months and in a menstruating girl genital bleeding desappeared after 1 month. Breast enlargement was reduced in all. In all children, the gonadotropin responses to LH-RH were suppressed and the inhibition of gonadal secretion persisted after 6 months of treatment. The data demonstrate the ability of long acting Trp6 to suppress gonadal secretion by a monthly injection in children with PP
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