40 research outputs found

    New detections of feldspar-bearing volcanic rocks in the walls of Valles Marineris, Mars

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    Data is a collection of Tiff files of the different series bundled into zip files.Eight new detections of plagioclase-like signatures are reported in their original geologic context in the walls of Valles Marineris. At one location, the feldspar signatures are clearly associated with a 200 m thick sub-horizontal layer, hinting at an eruptive origin. DTM and image were calculated using the NASA Ames Stereopipeline.Detection of plagioclase feldspar minerals from remote sensing instruments onboard Mars missions is difficult, and only a handful of occurrences have been reported so far. We present here new detections of such minerals in the giant martian canyon of Valles Marineris, exposed in their original context, and associated at least in one location, to a 200 m thick sub-horizontal layer within the walls. Analyses were performed using visible near-infrared spectral data, which are commonly compared to reference spectra of known terrestrial minerals, or mineral powders, acquired in the laboratory. Whereas previous detections were interpreted as evidence for plagioclase-dominated, or at least, nearly mafic-free, plutonic rocks, we argue here that the Valles Marineris outcrops correspond to erupted, volcanic products. The signature of plagioclase could originate from large crystals hosted in mafic, intermediate, or felsic volcanic rocks; from a lava flow, or from welded ashes. Our new observations confirm that plagioclase detections on Mars can correspond to multiple types of rocks and bring more clues to ongoing debates regarding the extent of Mars' magmatic processes and the nature of its crust.We are grateful to the Mars Reconnaissance Orbiter team for the availability of the data. This study was supported by the CNRS Momentum, LUE future leader programs, and the French “Program National de Planétologie”. The authors acknowledge the support of the French Agence Nationale de la Recherche (ANR), under grant ANR-21-CE49-0003 (MARS-Spec). CRISM data have been processed with the MarsSI (marssi.univ-lyon1.fr) application founded by the European Union’s Seventh Framework Program (FP7/2007-2013) (ERC Grant Agreement No. 280168). The component of the work by Frank Fueten was funded by an NSERC discovery grant

    Epilepsy with migrating focal seizures

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    To report new sporadic cases and 1 family with epilepsy of infancy with migrating focal seizures (EIMFSs) due to KCNT1 gain-of-function and to assess therapies' efficacy including quinidine. We reviewed the clinical, EEG, and molecular data of 17 new patients with EIMFS and KCNT1 mutations, in collaboration with the network of the French reference center for rare epilepsies. The mean seizure onset age was 1 month (range: 1 hour to 4 months), and all children had focal motor seizures with autonomic signs and migrating ictal pattern on EEG. Three children also had infantile spasms and hypsarrhythmia. The identified KCNT1 variants clustered as "hot spots" on the C-terminal domain, and all mutations occurred de novo except the p.R398Q mutation inherited from the father with nocturnal frontal lobe epilepsy, present in 2 paternal uncles, one being asymptomatic and the other with single tonic-clonic seizure. In 1 patient with EIMFS, we identified the p.R1106Q mutation associated with Brugada syndrome and saw no abnormality in cardiac rhythm. Quinidine was well tolerated when administered to 2 and 4-year-old patients but did not reduce seizure frequency. The majority of the KCNT1 mutations appear to cluster in hot spots essential for the channel activity. A same mutation can be linked to a spectrum of conditions ranging from EMFSI to asymptomatic carrier, even in the same family. None of the antiepileptic therapies displayed clinical efficacy, including quinidine in 2 patients

    Efficacy of vinblastine in central nervous system Langerhans cell histiocytosis: a nationwide retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Vinblastine (VBL) is the standard treatment for systemic Langerhans cell histiocytosis (LCH), but little is known about its efficacy in central nervous system (CNS) mass lesions.</p> <p>Methods</p> <p>A retrospective chart review was conducted. Twenty patients from the French LCH Study Group register met the inclusion criteria. In brief, they had CNS mass lesions, had been treated with VBL, and were evaluable for radiologic response.</p> <p>Results</p> <p>The median age at diagnosis of LCH was 11.5 years (range: 1-50). Intravenous VBL 6 mg/m<sup>2 </sup>was given in a 6-week induction treatment, followed by a maintenance treatment. The median total duration was 12 months (range: 3-30). Eleven patients received steroids concomitantly. Fifteen patients achieved an objective response; five had a complete response (CR: 25%), ten had a partial response (PR: 50%), four had stable disease (SD: 20%) and one patient progressed (PD: 5%). Of interest, four out of the six patients who received VBL without concomitant steroids achieved an objective response. With a median follow-up of 6.8 years, the 5-year event-free and overall survival was 61% and 84%, respectively. VBL was well-tolerated and there were no patient withdrawals due to adverse events.</p> <p>Conclusion</p> <p>VBL, with or without steroids, could potentially be a useful therapeutic option in LCH with CNS mass lesions, especially for those with inoperable lesions or multiple lesions. Prospective clinical trials are warranted for the evaluation of VBL in this indication.</p

    La formation des doctorants Ă  l'information scientifique et technique

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    La formation des doctorants aux problématiques de l'information scientifique et technique représente un enjeu particulièrement sensible pour l'enseignement supérieur et la recherche en France. Doublement affectée par de profondes transformations institutionnelles ainsi que par l'évolution accélérée des technologies numériques, la culture de l'information scientifique demeure l'un des piliers fondamentaux de la recherche et un élément incontournable dans la mise en œuvre d'une politique éclairée. La plupart des domaines d'activité du chercheur sont concernés : l'investigation, la propriété intellectuelle, la recherche documentaire, l'écriture scientifique, la publication, la communication scientifique, l'évaluation, les évolutions et les opportunités offertes par les outils numériques, la vulgarisation scientifique… Cet ouvrage se propose de poser quelques jalons afin d'alimenter la réflexion des divers protagonistes, universitaires, documentalistes, bibliothécaires, qui interviennent auprès du doctorant pour l'informer ou le guider tout au long de son parcours : quels seraient les attentes des doctorants et les besoins du monde académique ? Quelles connaissances et compétences les formateurs ont-ils à mobiliser ? Quels enseignements tirer des expériences et dispositifs mis en place ? Autant de questions pour approcher une thématique à la morphologie complexe. Le débat qu'elles suscitent met en lumière un bilan riche en interrogations et fécond pour l'avenir

    Reply to Baxter et al

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    What do monolingual and bilingual children with and without SLI produce when phonology is too complex?

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    International audienceIn this study, the authors compare the production of internal codas and branching onsets in four groups of children learning French: monolingual typically-developing children (n = 12), bilingual typically-developing children (n = 61), monolingual children with Specific Language Impairment (n = 17) and bilingual children with Specific Language Impairment (n = 20). Their elicited productions were collected using a nonword repetition task (LITMUS-NWR-French), containing 71 nonwords with different syllable types. Except for typically-developing monolingual children, all children performed significantly better on branching onsets than on internal codas. Moreover, the repair strategies used in erroneous productions also indicate that children had more difficulties with internal codas: all the cases of metathesis affecting a target internal coda resulted in the production of a branching onset whereas the contrary was not observed. The differences in the rates of target-like production and the patterns of metathesis of these two structures suggest that internal codas are more difficult than branching onsets for children learning French

    Remote Sensing Survey of Altiplano-Puna Volcanic Complex Rocks and Minerals for Planetary Analog Use

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    International audienceThe Altiplano-Puna Volcanic Complex (APVC) of the Central Andes is an arid region with extensive volcanism, possessing various geological features comparable to those of other solar system objects. The unique features of the APVC, e.g., hydrothermal fields and evaporite salars, have been used as planetary analogs before, but the complexity of the APVC presents a wealth of opportunities for more analog studies that have not been exploited previously. Motivated by the potential of using the APVC as an analog of the volcanic terrains of solar system objects, we mapped the mineralogy and silica content of the APVC up to ~100,000 km2 in northern Chile based on a combination of remote sensing data resembling those of the Moon and Mars. The band ratio indices of Landsat 8 Operational Land Imager multispectral images and mineral classifications based on spectral hourglass approach using Earth Observing-1 Hyperion hyperspectral images (both in the visible to shortwave infrared wavelengths) were used to map iron-bearing and alteration minerals. We also used Hyperion imagery to detect feldspar spectral signatures and demonstrated that feldspar minerals can be detected on non-anorthosites, which may influence interpretations of feldspar spectral signatures on Mars. From the Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Emissivity Dataset, we derived the silica percentage of non-evaporite rocks within errors of approximately 2–3 wt.% SiO2 for those in the 60–70 wt.% range (about 8 wt.% errors for the 50–60 wt.% range). Based on an integrated assessment of the three datasets, we highlighted three regions of particular interest worthy of further field investigation. We also evaluated the benefits and limitations of all three remote sensing methods for mapping key minerals and capturing rock diversity, based on available samples and existing geological maps

    Remote Sensing Survey of Altiplano-Puna Volcanic Complex Rocks and Minerals for Planetary Analog Use

    Get PDF
    The Altiplano-Puna Volcanic Complex (APVC) of the Central Andes is an arid region with extensive volcanism, possessing various geological features comparable to those of other solar system objects. The unique features of the APVC, e.g., hydrothermal fields and evaporite salars, have been used as planetary analogs before, but the complexity of the APVC presents a wealth of opportunities for more analog studies that have not been exploited previously. Motivated by the potential of using the APVC as an analog of the volcanic terrains of solar system objects, we mapped the mineralogy and silica content of the APVC up to ~100,000 km2 in northern Chile based on a combination of remote sensing data resembling those of the Moon and Mars. The band ratio indices of Landsat 8 Operational Land Imager multispectral images and mineral classifications based on spectral hourglass approach using Earth Observing-1 Hyperion hyperspectral images (both in the visible to shortwave infrared wavelengths) were used to map iron-bearing and alteration minerals. We also used Hyperion imagery to detect feldspar spectral signatures and demonstrated that feldspar minerals can be detected on non-anorthosites, which may influence interpretations of feldspar spectral signatures on Mars. From the Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Emissivity Dataset, we derived the silica percentage of non-evaporite rocks within errors of approximately 2&ndash;3 wt.% SiO2 for those in the 60&ndash;70 wt.% range (about 8 wt.% errors for the 50&ndash;60 wt.% range). Based on an integrated assessment of the three datasets, we highlighted three regions of particular interest worthy of further field investigation. We also evaluated the benefits and limitations of all three remote sensing methods for mapping key minerals and capturing rock diversity, based on available samples and existing geological maps
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