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Two temperature-dependent membrane fluidity regimes in Gram-positive bacteria
No full textIt is widely accepted that bacterial cells maintain a constant membrane fluidity in response to temperature changes. This process, known as membrane fluidity homeostasis, occurs through remodeling of plasma membrane composition. We tested this using an assay based on total internal reflection-fluorescence correlation spectroscopy (TIR-FCS) that directly quantifies membrane fluidity as the diffusion speed of a membrane marker in Bacillus subtilis and two other Gram-positive bacteria, Streptococcus pneumoniae and Staphylococcus aureus, across a temperature range of 20 °C to 37 °C. Instead of the expected constant membrane fluidity, we identified a two-component regime: membrane fluidity is maintained at low temperatures (<26 °C), but freely increases at higher temperatures
Far-reaching hunter-gatherer networks during the Last Glacial Maximum in Western Europe
No full textInternational audienceSocial networking is an essential feature of hunter-gatherer societies. It fosters the circulation of goods and information and enables kinship ties across different scales, including long-distance contacts. While such behaviors are known since at least the Upper Palaeolithic, evidence for geographically extensive social networks remains scarce. This evidence is limited to indirect inferences based on shared cultural traits, “art” styles, and symbolic items, while lithic raw material movements are mostly local and regional, with few cases exceeding 300 kilometers. We provide geochemical evidence for the largest confirmed distance between the source and discard location of a knapped lithic object in Palaeolithic Europe. Solutrean artifacts discarded at Peña Capón, Central Iberia, were sourced in Southwest France, 600 to 700 kilometers away. This demonstrates social networks of unprecedented geographic scale maintained during ∼1400 years during the Last Glacial Maximum. It also suggests that stone tools were exchanged as symbolic items to solidify social contacts and sustain far-reaching networks as risk-buffering mechanisms among widely dispersed hunter-gatherers
Influence of simulated vs. satellite-based burned areas on modelled terrestrial carbon fluxes
No full textInternational audienceBackgroundThe Global Carbon Project provides annual updates on anthropogenic and natural components of the Global Carbon Budget. Dynamic Global Vegetation Models (DGVMs) contribute to these estimates and are used to simulate the evolution of terrestrial carbon sinks. However, DGVMs are known to poorly represent disturbances such as fire, leading to uncertainties in estimates of mean, interannual variability (IAV), and trends in land carbon fluxes. To address this issue, we propose a hybrid-process-based assessmentby constraining three DGVMs (OCN, JULES-INFERNO, and ORCHIDEE-MICT) with remotely-sensed burned areas from ESA CCI (FIRECCI51) and climate data from ERA5 reanalysis. We aim to improve the representation of the spatio-temporal variability of regional carbon budgets, namely fire emissions, above-ground biomass carbon (AGC), and vegetation-related variables-leaf area index (LAI) and gross primary productivity (GPP). ResultsPrescribing burned area (BA) in DGVMs reveals contrasting patterns between prognostic (model simulations) and diagnostic (simulations with prescribed BA) runs. As prognostic tends to overestimate BA, particularly across tropical and high-latitude regions, diagnostic simulations correct this issue, by reducing bias and improving the IAV and the agreement with satellite-based datasets of BA and fire emissions in these regions. Moreover, enhanced IAV of AGC is simulated by diagnostic runs, essentially due to better representation of biomass carbon in the mentioned regions. Although moderate improvements are found in LAI and GPP, as the differences between the two runs are more limited, the improvements between prognostic and diagnostic are more evident in their IAV, particularly for LAI, rather than on long-term means, indicating that prescribed fire can improve the representation of some variability patterns.Conclusions Prescribing remotely-sensed BA in models can lead to a better representation of global BA, fire emissions and AGC, particularly improving the IAV, reducing bias and enhancing the agreement with satellite datasets. The moderate improvements in vegetation-related variables underscore the need to better constrain fire</div
Levels of circulating kidney injury markers and IL-10 identify non-critically ill patients with COVID-19 at risk of death
No full textInternational audienceBACKGROUNDAfter identifying 2 immunomarkers of acute injury, KIM-1 and LCN2, in all kidney biopsies from 31 patients with COVID-19 pneumonia and de novo kidney dysfunction, we investigated whether circulating markers of kidney epithelial injury are common in patients with laboratory-confirmed COVID-19 who require oxygen support but do not have critical illness.METHODSWe studied 196 patients admitted to 15 hospitals with moderate to severe pneumonia who were enrolled in 2 independent randomized clinical trials. We measured 41 immune mediators and markers of kidney and endothelial injury in peripheral blood in these patients within 24 hours of randomization.RESULTSWe constructed a generalized linear CORIMUNO model combining serum levels of KIM-1, LCN2, IL-10, and age at hospital admission that showed high discrimination for mortality (derivation cohort: AUC = 0.82, 95% CI: 0.73-0.92; validation cohort: AUC = 0.83, 95% CI: 0.74-0.92). An early rise in circulating kidney injury markers, in the absence of acute kidney injury criteria, was markedly associated with the risk of developing a severe form of COVID-19 and death within 3 months.CONCLUSIONThe CORIMUNO score may be a helpful tool for risk stratification, and for the first time to our knowledge, it identifies the overlooked impact of subclinical kidney injury on pneumonia outcomes.TRIAL REGISTRATIONClinicalTrials.gov NCT04324047, NCT04324073, and NCT04331808.FUNDINGThis research was funded by the French Ministry of Health, Programme Hospitalier de Recherche Clinique (PHRC COVID-19-20-0151, PHRC COVID-19-20-0029), Fondation de l'Assistance Publique Hôpitaux de Paris (Alliance Tous Unis Contre le Virus), Assistance Publique Hôpitaux de Paris, and grants from the Fondation pour la Recherche Médicale (FRM) (REA202010012514) and Agence Nationale de Recherches sur le Sida and emerging infectious diseases (ANRS) (ANRS0147) from the VINTED sponsorship
A high-dynamic-range view of the growth of structure and the warm/hot Universe
No full textInternational audienceBaryons heat to temperatures above as they accrete onto massive overdensities -- galaxies, groups, clusters, and filaments -- where they ionize and become optically transparent. Deep mm-wave observations such as those with ALMA have begun to probe a handful (4) of massive systems at , while low-resolution mm-wave surveys have detected thousands of objects at arcminute resolution out to . To truly advance the field of the evolution of large-scale structures, mapping the warm/hot distribution of ionized gas out to the redshift of their formation, the ESO community requires a large-aperture single-dish (sub-)mm telescope. This will need to provide several orders of magnitude higher mapping speeds than currently available while preserving the few arcsecond resolution required for imaging the gas and removing contaminating radio and dusty thermal signals across the full (sub-)mm wavelength range
SPATIALLY FILTERED SPARSE BAYESIAN LEARNING FOR DIRECTION-OF-ARRIVAL ESTIMATION WITH LEAKY-WAVE ANTENNAS
No full textInternational audienceDirection-of-arrival (DoA) estimation with leaky-wave antennas (LWAs) offers a compact and cost-effective alternative to conventional antenna arrays but remains challenging in the presence of coherent sources. To address this issue, we propose a spatially filtered sparse Bayesian learning (SF-SBL) framework. Firstly, the field of view (FoV) is divided into angular sectors according to the frequency beam-scanning property of LWAs, and Bayesian inverse problems are then solved within each sector to improve efficiency and reduce computational cost. Both on-grid SBL and off-grid SBL formulations are developed. Simulation results show that the proposed approach achieves robust and accurate DoA estimation, even with coherent sources
Generic crop rotation pattern-matching algorithm revealed dominant rotational systems for France
No full textInternational audienceCrop rotations remain poorly documented at large spatial scale, despite their central role in agroecosystem sustainability. We present a generic pattern-matching algorithm to infer crop rotations from annual crop sequence datasets, such as those derived from the European Land Parcel Identification System, with minimal crop aggregation. This method identifies field-level rotations, quantifies their flexibility, and enables spatially-explicit assessment of dominant crop and grasslands rotational systems at various spatial and thematic levels. Applied to mainland France, the approach identified crop rotations on 90% of arable area, with four-year rotations -typically including two to three years of flexible crops-being the most common. Nationally, the top 20 rotations accounted for 30% of arable land, while the top 52 covered 50%. At the agricultural district scale, we distinguished 25 dominant rotational systems grouped into eight categories, including (i) maize grain monocropping, (ii) maize grain -winter wheat rotations, (iii) sunflower -winter wheat rotations, (iv) grass-based systems, (v) maize silage -winter wheat rotations, (vi) winter wheat -barley -rapeseed rotations, (vii) root crop-based rotations, and (viii) specialized production. At national scale, organic rotations were longer and more flexible than conventional ones. Rotations of larger farms were longer and temporally more diverse than smaller ones, but showed lower spatial diversity. This scalable, data-driven approach offers new insights into crop rotation patterns and their spatial variability. It can support the large-scale assessment of agroecosystems with quantitative evidences on dominant rotations, but also help at tracking and characterizing localized rotational innovations
Plan de gestion des données de l’unité de recherche PROSE (UR1461 INRAE)
No full textL’unité PROSE mène des recherches sur les biotechnologies environnementales, depuis l’échelle des communautés microbiennes jusqu’à celle des procédés (stations d’épuration, digesteurs anaérobies, procédés bioélectrochimiques pour la bioraffinerie, …), en articulation avec les grands enjeux sociétaux de développement durable, d’économie circulaire et de bioéconomie. Affiliée aux départements TRANSFORM et MICA d’INRAE, l’unité PROSE s’inscrit dans une démarche transdisciplinaire fondée sur l’écologie microbienne, la biogéochimie, le génie des procédés, les mesures physiques et la modélisation.L’unité PROSE est composée d’un pôle de chercheurs et chercheuses porteurs de projets, d’un pôle analytique regroupant un laboratoire de microbiologie moléculaire et un laboratoire de chimie dotés d’équipements de pointe, et d’un pôle expérimentation ayant une capacité à déployer ses compétences à la fois à l’échelle pilote et sur le terrain.Ce plan s’inscrit dans le cadre des activités de recherche de l’unité PROSE et des projets de recherche auxquels elle contribue
Stepwise recombination suppression around the mating-type locus associated with a diploid-like life cycle in Schizothecium fungi
No full textInternational audienceRecombination suppression often evolves around sex-determining loci and extends stepwise, resulting in adjacent regions with different levels of divergence between sex chromosomes, called evolutionary strata. In Ascomycota fungi, evolutionary strata around the mating-type (MAT) locus have been reported only in pseudo-homothallic species, which have a diploid-like life cycle with mycelia carrying nuclei of both mating types. In contrast, no recombination suppression has been observed in heterothallic fungi, where colonies contain only a single mating type. Here, we investigated the evolution of recombination suppression in a clade of dung fungi encompassing 16 pseudo-homothallic and three heterothallic sibling species from the Schizothecium genus (Ascomycota, Sordariales). The analysis of genetic divergence based on genome sequencing indicated recombination suppression around the MAT locus in all 13 pseudo-homothallic species examined. The nonrecombining region ranged from 600 kb to 1.6 Mb and harbored multiple evolutionary strata, varying in size and number among species. The clustering of alleles according to mating type in gene genealogies, the high linkage disequilibrium, and an inversion in one species supported the lack of recombination in the MAT-proximal region in pseudo-homothallic species. The overall lack of trans-specific polymorphism suggested multiple independent recombination suppression events or occasional recombination/genic conversion. In heterothallic species, progeny analyses showed that recombination occurs in regions at physical distances from the MAT locus similar to those in which it is lacking in the pseudo-homothallic species. We thus revealed here multiple, likely independent evolutionary strata, associated with an extended diploid-like stage in Schizothecium fungi