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The mineralogical composition of Jezero Crater Western Fan: Multigaussian modeling of Perseverance/SuperCam near-infrared observations and overview of major units
No full textInternational audienceThe analysis of the mineralogical composition of rocks within the Jezero crater, Mars, enables the reconstruction of the aqueous activity history of the site, formed during the planet’s early epochs. Numerous secondary minerals resulting from aqueous alteration, as well as some primary minerals, are observable through near-infrared reflectance spectroscopy, as performed by the IRS/SuperCam instrument onboard the Perseverance rover. The characterization of these minerals, their distribution within geological units, as well as the composition of their assemblages, is crucial for deciphering the chemical, climatic, and geological history of the Jezero crater. In order to systematically study the growing number of IR spectra collected by the instrument, we have developed an automated method for extracting the characteristics of absorption bands, based on their modeling using a combination of Gaussian curves (MultiGM). The application of this method to the entire IRS dataset reveals a significant diversity of minerals distributed throughout the rover traverse, with a near-systematic presence of phyllosilicates in bedrocks, as well as increasingly frequent occurrences of carbonates on the delta, particularly within the Margin unit. These carbonates exhibit variable 2.5 m band positions attributed to different Fe and Mg compositions. The delta front presents the sole unit generally enriched in Fe/Mg sulfates (Yori Pass/Hogwallow Flats) accompanied by occurrences of bassanite (hydrated CaSO4), whereas the presence of sulfates in other delta units and the crater floor is more sporadic and corresponds to fracture/vesicle fills. Finally, almost all the rocks analyzed with IRS/SuperCam are notably dominated by phyllosilicates signatures (Fe/Mg-smectites, serpentine), excepted for a few outcrops caping the Delta. This phyllosilicate presence witnesses the extended surficial (smectites) and hydrothermal (serpentine) aqueous alteration of Jezero’s rocks, either in situ or carried from the watershed
Genomic prediction elucidates global genotype-by-environment interaction patterns for fruit firmness in apple (Malus domestica Borkh.)
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Trends of Publication of Negative Trials Over Time
No full textInternational audienceStudies with negative results are less likely to be published than others, potentially leading to publication bias. Introduced in 2000, trial registration could have participated in decreasing the proportion of unpublished studies. We assessed the proportion of negative randomized controlled trials (RCT) over the last 20 years. We searched Medline for RCT published in 2000, 2005, 2010, 2015, and 2020 in the British Medical Journal, the Journal of the American Medical Association, the Lancet, and the New England Journal of Medicine. The primary endpoint was the proportion of negative (final comparison on the primary study-endpoint without statistical significance or favoring the control arm) studies published in 2000 and 2020. Factors independently associated with the publication of negative studies were identified using multivariable analysis. A total of 1,542 studies were included. The proportion of negative RCT significantly increased between 2000 and 2020 (from 27.6% to 37.4%; P = 0.01), however, the trend over time was not significant (P = 0.203). In multivariable analysis, the following factors were associated with a higher proportion of published negative studies: superiority (P < 0.001), two-group trials (P < 0.001), number of patients ≥510 (P < 0.001), cardiology trials (P = 0.003), emergency/critical care trials (P < 0.001), obstetrics trials (P = 0.032), surgery trials (P = 0.006), pneumology trials (P = 0.029). Exclusive industry funding was associated with a lower proportion of published negative studies (P < 0.001). The proportion of published negative studies in 2020 was higher only when compared to 2000. During the two decades, no trend was noticeable. There is no clear relationship between trial registration and the publication of negative results over time
De l’essai aux essayismes diffus : la part singulière d’une forme de vie littéraire
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HOLIMITOX : Le réseau de chercheurs indépendants sur les pesticides SDHI.
No full textNational audienceHOLIMITOX : Le réseau de chercheurs indépendants sur les pesticides SDHI
Century-old herbarium specimen provides insights into Pierce’s disease of grapevines emergence in the Americas
No full textInternational audienceFossils and other preserved specimens are integral for informing timing and evolutionary history in every biological system. By isolating a plant pathogen genome from herbarium-preserved diseased grapevine material from 1906 (Herb_1906), we were able to answer questions about an enigmatic system. The emergence of Pierce’s disease (PD) of grapevine has shaped viticultural production in North America; yet, there are uncertainties about the geographic origin of the pathogen (Xylella fastidiosa subsp. fastidiosa, Xff) and the timing and route of its introduction. We produced a high-quality, de novo genome assembly of this historical plant pathogen and confirmed degradation patterns unique to ancient DNA. Due to the inclusion of the Herb_1906 sample, we were able to generate a significant temporal signal in the genomic data. This allowed us to build a time-calibrated phylogeny, where we estimate the introduction of Xff into the US between 1734 and 1741 CE, an earlier time frame than previously inferred. In a large collection of >300 Xff genomes, the Herb_1906 sample was genetically most similar to a small population from Northern California but not basal to the entire Xff California clade. Based on phylogenetic placement and a phylogeographic reconstruction, our data support a single introduction of Xff into the Southeastern US from Central America, with multiple subsequent introductions into California
Cooperative games with types, outside options, and the egalitarian value
No full textInternational audienceThis article introduces a new axiom of sub-game order preservation for TUgames as well as a model of cooperative games with types. The axiom, alongside efficiency, characterizes the egalitarian value. The model addresses situationswhere players of different types are needed. Each player has a specific type and coalitions are feasible only if it contains at most one player of each type. We use the new characterization of the egalitarian value for TU-games to obtain the following result in our class of problems: the egalitarian value is the only sharing rule that ensures that each player of the most productive group is better o joining this most productive group. We characterize the egalitarian value without fairness requirement and show that, for this new class of problems, egalitarianism can provide some form of incentives towards optimal cooperation
Prevalence of Liver Steatosis and Fibrosis in Adults With Primary Hypobetaliproteinemia: Results From the HYPOCHOL Study
No full textInternational audienceNo abstract availabl
Mars in Short: Past and Present Geology and Climate
No full textInternational audienceMars is the fourth planet from the Sun. Today it is cold, dry, and covered by a reddish bedrock and regolith. The surface is little protected from radiation due to a thin atmosphere and the lack of a substantial magnetic field. It is however thought to have been very different: that in its early history, about 4 Gyr ago, it had a thicker atmosphere and a magnetic field. Water seems to have flown, at least periodically, on the surface. It might even have harboured life. In this chapter, the major developments in Mars’s geological history, as well as its current environmental conditions, are laid out. They are then discussed in the context of space exploration. Our analysis suggests that resources for human explorers may be sourced on site, notably water, building materials, and nutrients for growing food. It also highlights the many hazards which would be faced on Mars, including radiation, a toxic and oxidizing soil, little organic material, and a harsh climate