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Assessing the efficiency of inequality changes in terms of poverty alleviation
No full textInternational audienceThis paper introduces a novel analytical approach to assess the efficiency of inequality reduction in poverty alleviation. I develop a general transform of theLorenz curve that enables the computation of point elasticities of poverty with respect to inequality while perfectly controlling for changes in inequality levels. Unlike previous methods, the suggested approach makes it possible to measure elasticities corresponding to observed inequality changes. It alsoprovides a framework for benchmarking these elasticities. These elasticities are estimated for different subperiods using Brazilian income distribution datafrom 1981-2022. Results show the increasing powerfulness of inequality reduction as a lever for poverty alleviation. Moreover, while decreasedinequality significantly contributed to poverty reduction during Brazil's celebrated poverty reduction period between 2003 and 2014, I observe that thedistributional changes were not more pro-poor, compared with later subperiods, yet more efficient than in earlier subperiods in terms of povertyreduction
The potential of carbohydrate supramolecular hydrogels for long-term 3D culture of primary fibroblasts
No full textInternational audienceN-alkyl-galactonamides are small synthetic molecules derived from galactose that self-assemble to give fibrous hydrogels. These molecules are biocompatible and in a previous study, the cell culture of human neural stem cells was performed for 7 days on a gel of N-heptyl-D-galactonamide. With the objective of broadening the scope of these molecules as scaffold for cell culture, in the present study, the culture of primary human dermal fibroblasts has been carried out on N-nonyl-D-galactonamide hydrogels. These supramolecular fibrillar hydrogels have a sufficient mechanical strength to withstand cell culture (≈50 kPa) and they were resistant enough on the long term to carry out the cell culture over at least 3 weeks. On the contrary to N-heptyl-D-galactonamide, N-nonyl-D-galactonamide is insoluble in the culture medium. It avoids its dissolution at each renewal of the culture medium. The molecule is only slowly eliminated by other mechanisms (1/3 in 3 weeks), which did not impair the cell culture on a monthly scale. The hydrogel's microstructure and how the cells organize on this scaffold has been studied using electron and two-photon microscopies. The gel is made of a quite homogeneous network of ≈180 nm wide and hundreds of µm long fibers, except at the surface where a dense mat of heterogeneous fibers are formed. We focused on methods able to colocalize the cells and the gel fibers. Many cell clusters have elongated and multidirectionnal shapes, guided by the fibers. Chains of single cells are also found following the fibers from one cluster to another. N-nonyl-D-galactonamide fibers which have the advantage of not being autofluorescent, do not mask the fluorescence of cells. But interestingly, they give a strong second harmonic generation (SHG) signal, due to their well-organized lamellar structure. We also made a special effort to visualize the penetration of cells within the depth of the hydrogels, in 3D, notably by sectioning the hydrogels, despite their softness. It showed that most of the cells stayed at the surface, but several ones grew within the supramolecular fibers network between 50-100 µm depth
Cation Vacancies in Ti‐Deficient TiO<sub>2</sub> Nanosheets Enable Highly Stable Trapping of Pt Single Atoms for Persistent Photocatalytic Hydrogen Evolution
No full textInternational audienceThe stabilization of single-atom catalysts on semiconductor substrates is pivotal for advancing photocatalysis. TiO2, a widely employed photocatalyst, typically stabilizes single atoms at oxygen vacancies—sites that are accessible but prone to agglomeration under illumination. Here, we demonstrate that cation vacancies in Ti-deficient TiO2 nanosheets provide highly stable anchoring sites for Pt single atoms, enabling persistent photocatalytic hydrogen evolution. Ultrathin TiO2 nanosheets with intrinsic Ti4+ vacancies are synthesized via lepidocrocite-type titanate delamination and Pt single atoms are selectively trapped within these vacancies through a simple immersion process. The resulting Pt-decorated nanosheets exhibit superior photocatalytic hydrogen evolution performance, outperforming both Pt nanoparticle-loaded nanosheets and benchmarked Pt single-atom catalysts on P25. Crucially, Pt atoms anchored at Ti4+ vacancies display remarkable resistance to light-induced agglomeration, a key limitation of conventional single-atom photocatalysts. Density functional theory calculations reveal that Pt incorporation into Ti4+ vacancies is highly thermodynamically favorable and optimizes hydrogen adsorption energetics for enhanced catalytic activity. This work highlights the critical role of cation defect engineering in stabilizing single-atom co-catalysts and advancing the efficiency and durability of photocatalytic hydrogen evolution
Satellite Requirements to Capture Water Propagation in Earth's Rivers
No full textInternational audienceThe water in Earth's rivers propagates as waves through space and time across hydrographic networks. A detailed understanding of river dynamics globally is essential for achieving accurate knowledge of surface water storage and fluxes to support water resources management and water-related disaster forecasting and mitigation. Global in situ information on river flows are crucial to support such an investigation but remain difficult to obtain at adequate spatiotemporal scales, if they even exist. Many expectations are placed on remote sensing techniques as key contributors. Despite a rapid expansion of satellite capabilities, however, it remains unclear what temporal revisit, spatial coverage, footprint size, spatial resolution, observation accuracy, latency time, and variables of interest from satellites are best suited to capture the space-time propagation of water in rivers. Additionally, the ability of numerical models to compensate for data sparsity through model-data fusion remains elusive. We review recent efforts to identify the type of remote sensing observations that could enhance understanding and representation of river dynamics. Key priorities include: (a) resolving narrow water bodies (finer than 50-100 m), (b) further analysis of signal accuracy versus hydrologic variability and relevant technologies (optical/SAR imagery, altimetry, microwave radiometry), (c) achieving 1-3 days observation intervals, (d) leveraging data assimilation and multi-satellite approaches using existing constellations, and (e) new variable measurement for accurate water flux and discharge estimates. We recommend a hydrologyfocused, multi-mission observing system comprising: (a) a cutting-edge single or dual-satellite mission for advanced surface water measurements, and (b) a constellation of cost-effective satellites targeting dynamic processes
Impact of Interfacial Friction at the Ice‐Bed Boundary on Glacier Sliding
No full textInternational audienceCurrent theories for describing glacier sliding over hard beds assume that basal drag is entirely due to normal forces acting on meter‐scale bed roughness and neglect tangential friction at the ice‐bed interface. However, this interfacial friction is likely to account for a significant proportion of basal drag in the presence of basal debris or cold ice, and may render current sliding theories inaccurate. The aim of the study is to evaluate if current sliding laws still apply in the presence of interfacial friction. We propose a simplified analytical model of glacier sliding controlled by both ice creep around bed irregularities, as proposed by Weertman (1957, https://doi.org/10.3189/s0022143000024709 ), and interfacial friction at the ice‐bed boundary determined by Coulomb dependency. We show that reduced sliding speed from additional interfacial friction is mitigated by increased ice deformation near the bed, which occurs as a result of additional basal deviatoric stresses reducing the effective viscosity. We further generalize these results using a numerical model of glacier sliding over a sinusoidal bed, capable of simulating cavity formation and basal sliding with several formulations of interfacial friction. We find that the additional friction generally does not modify the form of previously proposed friction laws but significantly increases the maximum resistive shear stress of the bed. These results suggest that friction laws that are commonly used in ice‐sheet models and whose parameters are empirically optimized, could be still used in circumstances where interfacial friction is non‐negligible
Chromosome-Level Genome Assembly and Annotation of Corallium rubrum : A Mediterranean Coral Threatened by Overharvesting and Climate Change
No full textInternational audienceAbstract Reference genomes are key resources in biodiversity conservation. Yet, sequencing efforts are not evenly distributed across the tree of life raising concerns over our ability to enlighten conservation with genomic data. Good-quality reference genomes remain scarce in octocorals while these species are highly relevant targets for conservation. Here, we present the first annotated reference genome in the red coral, Corallium rubrum (Linnaeus, 1758), a habitat-forming octocoral from the Mediterranean and neighboring Atlantic, impacted by overharvesting and anthropogenic warming-induced mass mortality events. Combining long reads from Oxford Nanopore Technologies (ONT), Illumina paired-end reads for improving the base accuracy of the ONT-based genome assembly, and Arima Hi-C contact data to place the sequences into chromosomes, we assembled a genome of 532 Mb (20 chromosomes, 309 scaffolds) with contig and scaffold N50 of 1.6 and 18.5 Mb, respectively. Fifty percent of the sequence (L50) was contained in seven superscaffolds. The consensus quality value of the final assembly was 42, and the single and duplicated gene completeness reported by BUSCO was 86.4% and 1%, respectively (metazoa_odb10 database). We annotated 26,348 protein-coding genes and 34,548 noncoding transcripts. This annotated chromosome-level genome assembly, one of the first in octocorals and the first in Scleralcyonacea order, is currently used in a project based on whole-genome resequencing dedicated to the conservation and management of C. rubrum
Unraveling the genetic basis of full flowering date in olive tree through QTL mapping approach: Towards climate-adaptive breeding
No full textThe experimental setup was established in Montpellier and Cordoba as part of the collaboration agreement between IFAPA and INRAE for cooperation research on olive breeding. We thank the members of IFAPA and the DiaScope experimental unit at INRAE Montpellier for managing this experimental layout, and the AFEF team within AGAP Institute for supporting the management costs of plant material in Montpellier. Molecular genotyping was realized at the regional genotyping technology platform, AGAP Institute CIRAD, and data analyses were performed with the support of MESO@LR-Platform at the University of Montpellier and the bioinformatics group of the UMR AGAP Institute, a member of the French Institute of Bioinformatics (IFB)—South Green Bioinformatics.Data availability: Raw sequences data are available in ClimOliveMed; GBS data of an F1 hybrid population "Olivière x Arbequina" of olive; European Nucleotide Archive; 2025-04-20; PRJEB88732. Genotypic data used for mapping in this study is publicly available on Figshare at: https://figshare.com/articles/dataset/Genotypic_data_of_F1_progeny_of_olive_tree_Olivi_re_x_Arbequina_/28804433.BackgroundFuture climate models project severe impacts on owering phenology of perennial fruit trees in the Mediterranean region under increasing global warming, including the olive tree, a key species extensively cultivated in the region. Thus, understanding the genetic factors regulating owering is crucial for providing knowledge to select suitable cultivars and designing future olive breeding programs. Here, we aimed to investigate the genetic control of full owering date (FFD) through Quantitative Trait Loci (QTL) mapping approach. Two high-density parental genetic maps, with more than 10k SNPs, were constructed based on an "Olivière" x "Arbequina" F1 hybrid progeny. Phenological observations of the same progeny were conducted across ve environments (site × season), and data served to compute Best Linear Unbiased Predictors (BLUPs) for FFD. Both FFD-based BLUPs and single-environment data were used to detect key QTLs, which were further explored through in-silico candidate genes investigation. ResultsAnalysis of FFD distribution highlighted a high heritability with transgressive segregation. A total of 18 signi cant QTLs were identi ed in BLUPs analysis, and six were selected as the most relevant. Two QTLs were co-detected on the same linkage groups (LGs) of both parental genetic maps in BLUPs and some environments: LG09 (qFDO9b/ qFDA9) and LG07 (qFDO7/ qFDA7). Additionally, four QTLs on LG3 (qFDA3), LG22 (qFDA22) and LG13 (qFDA13) on "Arbequina" map, and LG13 (qFDO13) on "Olivière" map were revealed in BLUPs as well as in some single-environment analyses. Both qFDA13 and qFDA22 were characterized both by higher explained variance (14.6% and 11.6%, respectively) and additive values (-1.09 and + 1.15, respectively). Candidate genes investigation revealed genes within key QTLs probably involved in transcription regulation, including WRKY71, RLT3, and ABSCISIC ACID-INSENSITIVE-5-LIKE, in addition to a transport protein: FT-INTERACTING protein1. Genes highlighted were shown to interact with main owering date regulators such as FLOWERING LOCUS T (FT) and FLOWERING LOCUS C (FLC). ConclusionOur study aimed to highlight the genetic control of the owering date in the olive tree. The genomic regions covered by the detected QTLs and the candidate genes identi ed represent valuable resources for further investigations through genome-wide association and functional genomics studies. These ndings will provide key information for applying genomic selection to develop new varieties more adapted to future climate projections.</div
Disentangling density and geometry in weather regime dimensions using stochastic twins
No full textInternational audienceLarge-scale atmospheric variability can be summarized by recurring patterns called weather regimes. Their properties, including predictability, have been studied using the local dimension, a geometrical estimate of degrees of freedom from multifractal theory. Local dimension estimates vary across regimes, decrease when a single regime dominates, and increase during transitions, supporting their dynamical significance. However, these variations stem not only from geometry but also from sampling density. We develop a null-hypothesis test using stochastic twins-Gaussian mixture-based surrogates matching atmospheric sampling density but with constant geometry-applied to ERA5 500 hPa fields. Density effects alone explain over 25% of local dimension variance and reproduce the dimension drop near regime peaks, indicating this behavior is density-driven, not geometric. The remaining variability is plausibly geometry-driven. This approach, applicable to any observed system with known sampling distribution, offers a new framework for interpreting local dimension estimates in atmospheric and oceanic data
Gene network topology drives the mutational landscape of gene expression
No full textInternational audienceRegulatory mutations, coding sequence variations, and gene deletions and duplications are generally expected to have qualitatively different effects on fitness during adaptation. We aim to ground this expectation within a theoretical framework using evolutionary simulations of gene regulatory networks (GRNs) controlling the expression of fitness-related genes. We examined the distribution of fitness effects as a function of the type of mutation and the topology of the gene network. Contrary to our expectation, the GRN topology had more influence on the effect of mutations than the type of mutation itself. In particular, the topology conditioned (i) the speed of adaptation, (ii) the distribution of fitness effects, and (iii) the degree of pleiotropy which acts as explanatory factor for all mutation types. All mutations had the potential to participate in adaptation, although their propensity to generate beneficial variants differed according to the network topology. In scale-free networks, arguably the most common topology for biological networks, coding mutations were more pleiotropic and overrepresented in both beneficial and deleterious mutations, while regulatory mutations were more often neutral. However, this observation was not general, as this pattern was reversed in the other network topologies. These results highlight the critical role of gene interactions in defining mutations’ contributions to adaptation
Interplay between large low-recombining regions and pseudo-overdominance in a plant genome
No full textData availability: The fastq files for the Senegalese, temporal and WGS datasets were deposited in GenBank under Bioproject PRJNA805042 and PRJNA771656. The VCF files and the scaffolds of Autof-Pod103sr8 that support the findings of this study are openly available in the DataSuds repository (IRD, France) [https://doi.org/10.23708/SN2T4A]. Long reads and optical mapping data of the Autof-Pod103sr8 genotype can be found under ENA accession study PRJEB57746. ONT long reads are accessible with ENA accession ERR12178246. Assembly of Autof-Pod103sr8 at the contig-level was deposited on ENA under accession CAVLDM02. The GFF file of the annotation transfer to the scaffolds of Autof-Pod103sr8 is accessible with ENA accession ERZ22147468. Bionano raw data and assembled optical maps for Autof-Pod103sr8 can be found under ENA accession ERZ21830311. Optical maps for the PMiGAP257 genotype are available under ENA accession ERZ14864807. Source data are provided with this paper and GitHub repository [https://github.com/msalson/low-recombining_regions_study]. Source data are provided with this paper.Code availability: The code used for the analyses performed in the study can be found on GitHub [https://github.com/msalson/low-recombining_regions_study and https://github.com/stella-huynh/localPCA].International audienceTo what extent overdominance might contribute to the maintenance of genetic diversity within genomes is still an ongoing research question. Pseudo-overdominance created by the complementation of deleterious alleles in heterozygotes has recently become a subject of particular interest. Simulations and theory suggest that pseudo-overdominance may occur in low recombining regions. Here, we conduct a comprehensive investigation of large low-recombining (LLR) regions in cultivated populations of pearl millet, an outcrossing diploid African cereal. We examine seven large regions ranging from 5 to 88 Mb and six of them are pericentromeric. These LLR regions exhibit an excess of heterozygotes, a distinctive hallmark of overdominance. They display a tendency toward a higher diversity and a larger ratio of non-synonymous and deleterious variants. We conduct a more in-depth study of the largest 88 Mb region, identified on chromosome 3. Interestingly, haplotypes of this region have been introgressed from wild relatives. Using long read sequencing, we confirm their strong divergence and the presence of inversions across one of them. One of the haplotypes seems to be highly deleterious in the homozygous state. A total of 17% of the cultivated pearl millet genome exhibit a local population structure suggestive of overdominance or possibly pseudo-overdominance. Our empirical results contribute to the accumulation of knowledge, which will enhance our understanding of the potential role of overdominance or pseudo-overdominance in maintaining genetic diversity, particularly in low recombining regions