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De l'émigration à l'asile : l'accueil sélectif des exilés en Pologne
No full textInternational audienceIn 2015, the conservative Law and Justice party came to power in Poland by exploiting the fear of migrants. This position was confirmed in 2021 with the militarisation of the Polish-Belarusian border. The arrival of more than a million Ukrainian refugees following Russia's invasion of their country has turned Poland into a paradoxical host country, implying a logic of differentiation and racialisation of the population with which community organisations are confronted.En 2015, le parti conservateur Droit et Justice accède au pouvoir en Pologne en instrumentalisant la peur des migrants. Cette position est réaffirmée en 2021 avec la militarisation de la frontière polono-biélorusse. L’arrivée de plus d’un million de réfugiés ukrainiens après l’invasion de leur pays par la Russie transforme la Pologne en un pays d’accueil paradoxal, impliquant des logiques de différenciation et de racialisation des populations auxquelles sont confrontés les acteurs associatifs. Malgré la volonté annoncée par la majorité libérale arrivée au pouvoir fin 2023 d’y mettre fin, les maltraitances à la frontière persistent
Contextualising transcription factor binding during embryogenesis using natural sequence variation
No full textUnderstanding how genetic variation impacts transcription factor (TF) binding remains a major challenge, limiting our ability to model disease-associated variants. Here, we used a highly controlled system of F1 crosses with extensive genetic diversity to profile allele-specific binding of four TFs at several embryonic time-points, using Drosophila as a model. Using a combined haplotype test, we identified 9-18% of TF bound regions impacted by genetic variation. By expanding WASP (a tool for allele-specific read mapping) to examine INDELs, we increased detection of allele imbalanced (AI) peaks by 30-50%. This fine-grained ‘mutagenesis’ could reconstruct functionalized binding motifs of all factors. To prioritise potential causal variants, we trained a convolutional neural network (Basenji) to predict TF binding from DNA sequence. The model could accurately predict experimental AI for strong effect variants, providing a mechanistic interpretation for how genetic variation impacted TF binding. This revealed unexpected relationships between TFs, including potential cooperative pairs, and mechanisms of tissue specific recruitment of the ubiquitous factor CTCF
Revisiting the Intergalactic Medium Around GRB 130606A and Constraints on the Epoch of Reionization
No full textInternational audienceGamma-ray bursts (GRBs) are excellent probes of the high-redshift Universe due to their high luminosities and the relatively simple intrinsic spectra of their afterglows. They can be used to estimate the fraction of neutral hydrogen (i.e., neutral fraction) in the intergalactic medium at different redshifts through the examination of their Lyman-alpha damping wing with high quality optical-to-near-infrared spectra. Neutral fraction estimates can help trace the evolution of the Epoch of Reionization, a key era of cosmological history in which the intergalactic medium underwent a phase change from neutral to ionized. We revisit GRB 130606A, a z ~ 5.9 GRB for which multiple analyses, using the same damping wing model and data from different telescopes, found conflicting neutral fraction results. We identify the source of the discrepant results to be differences in assumptions for key damping wing model parameters and data range selections. We perform a new analysis implementing multiple GRB damping wing models and find a 3-sigma neutral fraction upper limit ranging from xHI < 0.20 to xHI < 0.23. We present this result in the context of other neutral fraction estimates and Epoch of Reionization models, discuss the impact of relying on individual GRB lines of sight, and highlight the need for more high-redshift GRBs to effectively constrain the progression of the Epoch of Reionization
Identification and Functional Characterization of Regulatory Variants in DPP9 Associated with COVID-19 Severity
No full textSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to a wide-range of clinical outcomes, which have been extensively studied through genome-wide association studies (GWAS). Starting from lead genetic variants associated with COVID-19 infection and severity, we identified a subset of non-coding candidate variants with potential regulatory functions. Using bioinformatics analysis and functional screening in three cell lines, we prioritized two DPP9 variants within a haplotype that increases the risk of severe COVID-19. This haplotype exhibited increased regulatory activity and altered transcription factor binding, suggesting its role in influencing COVID-19 severity through modulation of DPP9 expression in immune and lung cell types. The interest of our study lies in the functional characterization of regulatory variants responsible for the higher levels of DPP9 and lung damage observed in patients with severe COVID-19. These findings advance our understanding of genetic risk factors for COVID-19 and highlight functional SNPs that may guide future therapeutic research
Pacmanvirus isolated from the Lost City hydrothermal field extends the concept of transpoviron beyond the family Mimiviridae
No full textInternational audienceThe microbial sampling of submarine hydrothermal vents remains challenging, with even fewer studies focused on viruses. Here we report the first isolation of a eukaryotic virus from the Lost City hydrothermal field, by co-culture with the laboratory host Acanthamoeba castellanii. This virus, named pacmanvirus lostcity, is closely related to previously isolated pacmanviruses (strains A23 and S19), clustering in a divergent clade within the long-established family Asfarviridae. Its icosahedral particles are 200 nm in diameter, with an electron-dense core surrounded by an inner membrane. Its genome of 395,708 bp (33% G+C) is predicted to encode 473 proteins. However, besides these standard properties, pacmanvirus lostcity was found associated with a new type ofselfish genetic element, 7 kb in length, whose architecture and gene content are reminiscent of those of transpovirons, hitherto specific to the family Mimiviridae. Like previously described transpovirons, this element propagates as an episome within its host virus particles and exhibits partial recombination with its genome. In addition, an unrelated 2 kb long episome was also associated with pacmanvirus lostcity. Together, the transpoviron and the 2 kb episome might participate to exchanges between pacmanviruses and other large DNA virus families. It remains to be elucidated if the presence of these mobile genetic elements is restricted to pacmanviruses or wassimply overlooked in other members of the Asfarviridae
Bi3+ doped Na2O-TiO2-P2O5 phosphate glasses: Insight into structural, physical, mechanical, thermal, chemical, crystallization, dielectric, and energy storage properties
No full textInternational audiencePhosphate glasses hold promise for a variety of applications ranging from electrochemical cells to electro-optical devices. This paper details the elaboration and characterization of a series of Bi2O3 doped alkaline-phosphate glasses in the (55-x)Na2O-xBi2O3-5TiO2-40P2O5 system. A set of physical, structural, thermal, and electrical, characterizations have been carried out to understand the structural role of Bi2O3 in these glasses and provide insights into their overall stability and functional characteristics. As more Bi2O3 is incorporated into the glass up to 10 mol%, spectroscopy results showed local structural changes, with increased density, and glass transition temperature alongside enhanced mechanical properties and chemical durability. Additionally, the study involved the exploitation of heat treatment to induce the crystallization of vitreous samples through controlled crystallization. The 299.5 kJ/mol−1 energy of crystallization, signifies the amount of energy required for the transition from an amorphous to a crystalline state. The kinetics parameter identified the capacity for bulk nucleation in a single dimension of crystallite growth. The natures of the crystalline phases were determined with X-ray diffraction. Dielectric parameters and energy storage capacities were improved substantially with increasing Bi2O3 concentration, with a recoverable energy density peaked at 10.72 mJ/cm3 with 10 mol% Bi2O3, highlighting their potential for energy storage applications. A correlation between the thermal, dielectric, and structural properties of these glasses has been established