piRNAs and Aubergine cooperate with Wispy poly(A) polymerase to stabilize mRNAs in the germ plasm

Piwi-interacting RNAs (piRNAs) and PIWI proteins play a crucial role in germ cells by repressing transposable elements and regulating gene expression. In Drosophila, maternal piRNAs are loaded into the embryo mostly bound to the PIWI protein Aubergine (Aub). Aub targets maternal mRNAs through incomplete base-pairing with piRNAs and can induce their destabilization in the somatic part of the embryo. Paradoxically, these Aub-dependent unstable mRNAs encode germ cell determinants that are selectively stabilized in the germ plasm. Here we show that piRNAs and Aub actively protect germ cell mRNAs in the germ plasm. Aub directly interacts with the germline-specific poly(A) polymerase Wispy, thus leading to mRNA polyadenylation and stabilization in the germ plasm. These results reveal a role for piRNAs in mRNA stabilization and identify Aub as an interactor of Wispy for mRNA polyadenylation. They further highlight the role of Aub and piRNAs in embryonic patterning through two opposite functions

Influence of the cement composition on the radiolytic behavior under irradiation

International audienceCement based materials are used for the conditioning of Low and Intermediate Level Wastes (LILW)due to their low cost, their ease of making and their ability to immobilize radioelements. Nevertheless,hydrogen gas is produced radiolytically under irradiation. For the safety of nuclear waste disposals, itis important to limit as much as possible the hydrogen gas release.A comparison of the behavior of Portland and Ciment Fondu® cements under irradiation taking intoaccount both real cement pastes and synthetic hydrates was performed to find out the role of the cementcomposition on the radiolytic behavior under irradiation. First, γ-irradiations were performed usinga 60Co source (dose rate: 0.17 - 0.25 Gy.s-1, dose: up to 500×103 Gy). Thermogravimetric analysismeasurements were performed in order to determine the amount and the type of water involved. H2gas production was measured by gas chromatography. Regardless of the water to cement ratio (W/C)chosen (0.2, 0.4 and 0.6), it is shown that Ciment Fondu® pastes produce less H2 under irradiation. Inagreement with a recent study by Kadissy et al. [1], it is shown that the amount of gas produced byportlandite and gibbsite, which are respectively the constitutive hydrates of Portland and Ciment Fondu® cements, strongly depends on the nature of the hydrate. Secondly, portlandite and gibbsite wereirradiated by electrons up to 270 MGy and 3.5 GGy using the LSI SIRIUS accelerator platform. X-RayDiffraction analyses were performed before and after irradiation in order to investigate the structuraldamage. Despite some observed disorder, results show a good structural stability for both hydratesunder irradiation

H2 production under gamma irradiation of a calcium aluminate cement: an experimental study on both cement pastes and its stable hydrates

International audienceThe objective of this paper is to investigate the use of calcium aluminate cements as alternative cements within the context of nuclear waste stabilization by solidification. Using an external 60 Co source, the effect of γ-radiation on H2 gas production of one of the calcium aluminate cement-based materials (cement "Ciment Fondu") and its stable hydrates, was studied. The amount of H2 produced by these cement pastes is found to be much lower (up to five times less) than that of the Portland cement pastes containing the same amount of water, especially in the low range of water to cement ratios (W/C ≤ 0.4) where water is essentially engaged in the hydrates. The H2 production of the two major hydrates of Ciment Fondu, gibbsite AH3 and katoite hydrogarnet C3AH6, is very low compared with that of the main hydrates of other cements (Portland cement, Calcium Sulfo-Aluminate and Magnesium Phosphate cements). The type of water engaged in the hydrates, as hydroxyl groups and/or molecular water, influences significantly the H2 production. Thus, the nature of the hydrate is a key parameter to the aim of optimizing cement matrices with respect to the gas production under irradiation. XRD analysis shows that the crystal structures of gibbsite and katoite are preserved up to very high doses under electron irradiation (3 GGy). This makes calcium aluminate cements (CAC) potential good candidates for nuclear waste conditioning from the point of view of their stability under irradiation

French coastal network for carbonate system monitoring: The CocoriCO2 dataset

International audienceSince the beginning of the industrial revolution, atmospheric carbon dioxide (CO2) concentrations have risen steadily and have induced a decrease of the averaged surface ocean pH by 0.1 units, corresponding to an increase in ocean acidity of about 30%. In addition to ocean warming, ocean acidification poses a tremendous challenge to some marine organisms, especially calcifiers. The need for long-term oceanic observations of pH and temperature is a key element to assess the vulnerability of marine communities and ecosystems to these pressures. Nearshore productive environments, where a large majority of shellfish farming activities are conducted, are known to present pH levels as well as amplitudes of daily and seasonal variations that are much larger than those observed in the open ocean. Yet, to date, there are very few coastal observation sites where these parameters are measured simultaneously and at high frequency

French coastal network for carbonate system monitoring: the CocoriCO2 dataset

International audienceSince the beginning of the industrial revolution, atmospheric carbon dioxide (CO2) concentrations have risen steadily and have induced a decrease of the averaged surface ocean pH by 0.1 units, corresponding to an increase in ocean acidity of about 30 %. In addition to ocean warming, ocean acidification poses a tremendous challenge to some marine organisms, especially calcifiers. The need for long-term oceanic observations of pH and temperature is a key element to assess the vulnerability of marine communities and ecosystems to these pressures. Nearshore productive environments, where a large majority of shellfish farming activities are conducted, are known to present pH levels as well as amplitudes of daily and seasonal variations that are much larger than those observed in the open ocean. Yet, to date, there are very few coastal observation sites where these parameters are measured simultaneously and at high frequency. To bridge this gap, an observation network was initiated in 2021 in the framework of the CocoriCO2 project. Six sites were selected along the French Atlantic and Mediterranean coastlines based on their importance in terms of shellfish production and the presence of high- and low-frequency monitoring activities. At each site, autonomous pH sensors were deployed, both inside and outside shellfish production areas, next to high-frequency CTD (conductivity–temperature–depth) probes operated through two operating monitoring networks. pH sensors were set to an acquisition rate of 15 min, and discrete seawater samples were collected biweekly in order to control the quality of pH data (laboratory spectrophotometric measurements) as well as to measure total alkalinity and dissolved inorganic carbon concentrations for full characterization of the carbonate system. While this network has been up and running for more than 2 years, the acquired dataset has already revealed important differences in terms of pH variations between monitored sites related to the influence of diverse processes (freshwater inputs, tides, temperature, biological processes). Data are available at https://doi.org/10.17882/96982 (Petton et al., 2023a)

Social and clinical vulnerability in stroke and STEMI management during the COVID-19 pandemic: a registry-based study

Objective This study aims to evaluate whether the first wave of the COVID-19 pandemic resulted in a deterioration in the quality of care for socially and/or clinically vulnerable stroke and ST-segment elevation myocardial infarction (STEMI) patients.Design Two cohorts of STEMI and stroke patients in the Aquitaine neurocardiovascular registry.Setting Six emergency medical services, 30 emergency units, 14 hospitalisation units and 11 catheterisation laboratories in the Aquitaine region in France.Participants This study involved 9218 patients (6436 stroke and 2782 STEMI patients) in the neurocardiovascular registry from January 2019 to August 2020.Primary outcome measures Care management times in both cohorts: first medical contact-to-procedure time for the STEMI cohort and emergency unit admission-to-imaging time for the stroke cohort. Associations between social (deprivation index) and clinical (age >65 years, neurocardiovascular history) vulnerabilities and care management times were analysed using multivariate linear mixed models, with an interaction on the time period (pre-wave, per-wave and post-first COVID-19 wave).Results The first medical contact procedure time was longer for elderly (p<0.001) and ‘very socially disadvantaged’ (p=0.003) STEMI patients, with no interaction regarding the COVID-19 period (age, p=0.54; neurocardiovascular history, p=0.70; deprivation, p=0.64). We found no significant association between vulnerabilities and the admission imaging time for stroke patients, and no interaction with respect to the COVID-19 period (age, p=0.81; neurocardiovascular history, p=0.34; deprivation, p=0.95).Conclusions This study revealed pre-existing inequalities in care management times for vulnerable STEMI and stroke patients; however, these inequalities were neither accentuated nor reduced during the first COVID-19 wave. Measures implemented during the crisis did not alter the structured emergency pathway for these patients.Trial registration number NCT0497920