6 research outputs found

    Generic magnetic field intensity profiles of interplanetary coronal mass ejections at Mercury, Venus and Earth from superposed epoch analyses

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    We study interplanetary coronal mass ejections (ICMEs) measured by probes at different heliocentric distances (0.3-1 AU) to investigate the propagation of ICMEs in the inner heliosphere and determine how the generic features of ICMEs change with heliospheric distance. Using data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER), Venus Express and ACE spacecraft, we analyze with the superposed epoch technique the profiles of ICME substructures, namely, the sheath and the magnetic ejecta. We determine that the median magnetic field magnitude in the sheath correlates well with ICME speeds at 1 AU, and we use this proxy to order the ICMEs at all spacecraft. We then investigate the typical ICME profiles for three categories equivalent to slow, intermediate, and fast ICMEs. Contrary to fast ICMEs, slow ICMEs have a weaker solar wind field at the front and a more symmetric magnetic field profile. We find the asymmetry to be less pronounced at Earth than at Mercury, indicating a relaxation taking place as ICMEs propagate. We also find that the magnetic field intensities in the wake region of the ICMEs do not go back to the pre-ICME solar wind intensities, suggesting that the effects of ICMEs on the ambient solar wind last longer than the duration of the transient event. Such results provide an indication of physical processes that need to be reproduced by numerical simulations of ICME propagation. The samples studied here will be greatly improved by future missions dedicated to the exploration of the inner heliosphere, such as Parker Solar Probe and Solar Orbiter.Peer reviewe

    3-Methoxypyrazoles from 1,1-dimethoxyethene, few original results

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    International audienceFrom the condensation between 1,1-dimethoxyethene and anhydrides, synthetically useful b,bedimethoxyea,b-unsaturated ketones were prepared. Upon addition of hydrazine, followed by iodination, 4-iodinated 3-methoxypyrazoles were obtained. The occurrence of a side compound also provided insights in the scope of this synthesis. In a second part, 1-(4-chlorophenyl)-3,3-dimethoxyprop- 2-en-1-one was obtained from 1,1-dimethoxyethene and 4-chlorobenzoylchloride. The subsequent addition of hydrazine or phenylhydrazine led to 5-(4-chlorophenyl)-3-methoxy-1H-pyrazole or 1-phenyl- 5-(4-chlorophenyl)-3-methoxypyrazole in unprecedented 64 or 54% overall yield. Unexpectedly, addition of 2-pyridylhydrazine led to the 2-([1,2,4]triazolo[4,3-a]pyridin-3-yl)-1-(4-chlorophenyl) ethanone. This led us to design original conditions, which led to the target 1-(2-pyridyl)-5-(4-chlorophenyl)-3- methoxypyrazole in a 39% overall yield. Additional examples are provided, starting from various carboxychlorides

    Identité éditoriale, identités sportives

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    Le Dossier analyse l’assignation d’identités catégorielles aux sportifs de haut niveau dans la presse. Les Échanges étudient l’intervention par l’image. Les Notes de recherche traitent la « relation diagnostique », la manière dont l’Université rend hommage à ses membres décédés, le rapport entre ludique et marchand d’un parc d’attraction pour enfants, l’expertise du jazz, le complotisme sur Facebook et la diversité des langues dans la musique populaire. En VO suit les représentations médiatiques de la violence genrée aux USA. Le Focus porte sur Les Sensibilités religieuses blessées de Jeanne Favret-Saada et 33 Newport Street de Richard Hoogart. Les Notes de lecture recensent 50 ouvrages. The media discourse on sport often focuses on elite athletes and assigns to them categorical identities (class, gender, race, origin, age…) for various emblematic purposes (for example, national heroes, representatives of a territory, of a culture…). The Issue analyzes these identification logics and their variations – according to editorial strategies and the readers communities built – in the specialized press and the sport sections of the generalist press, without forgetting to consider their reception by the athletes themselves. The Exchanges extend André Gunthert’s discussion on the intervention through the image. The Research Notes explore the “diagnostic relationship” for patients with West Syndrome and their families, how universities honor their deceased members, the relationship between play, commercial and educational practices in a children amusement park, the expertise of jazz in France, the conspiracy speeches on Facebook and the diversity of languages in French popular music. In Original Version, US researcher Lisa Cuklanz revisits three decades of work on representations of gendered violence in mainstream media. The Focus section provides an in-depth reading of a recent work by Jeanne Favret-Saada – Hurt Religious Feelings. Christianity, Blasphemy and Films, 1965-1988 – and on an older one by Richard Hoggart – A Local Habitation, 1918–40. The Book Reviews offer succinct overviews and analyses of more than 50 publications

    New OFSEP recommendations for MRI assessment of multiple sclerosis patients: Special consideration for gadolinium deposition and frequent acquisitions

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    International audiencePurposeNew multiple sclerosis (MS) disease-modifying therapies (DMTs), which exert beneficial effects through prevention of relapse, limitation of disability progression, and improvement of patients’ quality of life, have recently emerged. Nonetheless, these DMTs are not without associated complications (severe adverse events like. progressive multifocal leukoencephalopathy). Patient follow-up requires regular clinical evaluations and close monitoring with magnetic resonance imaging (MRI). Detection of new T2 lesions and potential brain atrophy measurements contribute to the evaluation of treatment effectiveness. Current MRI protocols for MS recommend the acquisition of an annual gadolinium (Gd) enhanced MRI, resulting in administration of high volume of contrast agents over time and Gd accumulation in the brain.MethodsA consensus report was established by neuroradiologists and neurologists from the French Observatory of MS, which aimed at reducing the number of Gd injections required during MS patient follow-up.RecommendationsThe French Observatory of MS recommends the use of macrocyclic Gd enhancement at time of diagnosis, when a new DMT is introduced, at 6-month re-baseline, and when previous scans are unavailable for comparison. Gd administration can be performed as an option in case of relapse or suspicion of intercurrent disease such as progressive multifocal leukoencephalopathy. Other follow-up MRIs do not require contrast enhancement, provided current and previous MRI acquisitions follow the same standardized protocol including 3D FLAIR sequences

    Active Surveillance Program to Increase Awareness on Invasive Fungal Diseases: the French RESSIF Network (2012 to 2018)

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    International audienceThe French National Reference Center for Invasive Mycoses and Antifungals leads an active and sustained nationwide surveillance program on probable and proven invasive fungal diseases (IFDs) to determine their epidemiology in France. Between 2012 and 2018, a total of 10,886 IFDs were recorded. The incidence increased slightly over time (2.16 to 2.36/10,000 hospitalization days, P = 0.0562) in relation with an increase of fungemia incidence (1.03 to 1.19/10,000, P = 0.0023), while that of other IFDs remained stable. The proportion of ≥65-year-old patients increased from 38.4% to 45.3% (P 60% of the cases) with a global mortality rate of 42.5% and 59.3%, respectively, at 3 months and significant changes in diagnosis procedure over time. More concurrent infections were also diagnosed over time (from 5.4% to 9.4% for mold IFDs, P = 0.0115). In conclusion, we observed an aging of patients with IFD with a significant increase in incidence only for yeast fungemia, a trend toward more concurrent infections, which raises diagnostic and therapeutic issues. Overall, global survival associated with IFDs has not improved despite updated guidelines and new diagnostic tools.IMPORTANCE The epidemiology of invasive fungal diseases (IFDs) is hard to delineate given the difficulties in ascertaining the diagnosis that is often based on the confrontation of clinical and microbiological criteria. The present report underlines the interest of active surveillance involving mycologists and clinicians to describe the global incidence and that of the main IFDs. Globally, although the incidence of Pneumocystis pneumonia, invasive aspergillosis, and mucormycosis remained stable over the study period (2012 to 2018), that of yeast fungemia increased slightly. We also show here that IFDs seem to affect older people more frequently. The most worrisome observation is the lack of improvement in the global survival rate associated with IFDs despite the increasing use of more sensitive diagnostic tools, the availability of new antifungal drugs very active in clinical trials, and a still low/marginal rate of acquired in vitro resistance in France. Therefore, other tracks of improvement should be investigated actively

    Clinical spectrum and prognostic value of CNS MOG autoimmunity in adults: The MOGADOR study

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