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DNA damage and reactive oxygen species (ROS) generated by ionizing radiation (IR) activate DNA damage response (DDR) and cytokine signaling pathways, including double strand break (DSB) repair and TGFβ/Smad signaling pathway. Proteins assembled at IR-induced DSB sites can be visualized as foci, including γH2AX, 53BP1, ATM and ATF2. Unrepaired DSBs are thought to be one origin of micronuclei (MN), an indicator of genotoxic stress and chromosomal instability. Studies have detected γH2AX in IR-induced MN, indicating the presence of DSB in MN. Previously we reported that TGFβ downstream proteins Smad7 and phospho-Smad2 (pSmad2) co-localized with DDR proteins following radiation. Here we studied the status of Smad7 and pSmad2 in MN post high linear energy transfer (LET) radiation in human normal and cancerous cells. We observed γH2AX foci in IR-induced MN, whereas 53BP1 and ATF2 were absent. Interestingly, Smad7 foci, but not pSmad2, were detectable in both spontaneous and IR-induced MN. We compared the effect of particle track structures on the yield of MN using 5.6MeV/u boron (B) and 600MeV/u iron (Fe) particles with similar LET (200 and 180keV/μm, respectively) in human fibroblasts. The frequency of MN induced by B was lower than that by Fe particles, albeit the proportion of Smad7-positive to Smad7-negative MN remained constant. An increased frequency of spontaneous MN, with slightly higher ratio of Smad7 or γH2AX positive, was found in human prostate cancer cells (PC3) compared to normal cells. 24h after 1Gy of Fe particles exposure, the yield of MN increased, and the majority (∼70%) carried γH2AX and Smad7. Phospho-ATM (Ser1981) foci were found in both spontaneous and IR-induced MN in PC3 cells, displaying a much lower frequency compared to γH2AX and Smad7. Our data suggest a unique role of Smad7 in IR-induced MN formation, which may associate with DNA repair, apoptosis and genomic instability.

AbstractThe summer of 2018 was characterized by prolonged heatwaves over Northern Europe, associated with persistent atmospheric blocking, and an unusually northward jet stream location over Scandinavia. Whilst event attribution studies tend to focus on the change in probability or magnitude of the extreme temperatures themselves, we provide context to these studies by examining whether there are human induced trends in the atmospheric circulation that might affect the likelihood of similar extreme circulation patterns and associated heat waves occurring in the future. We examine trends and variability in summer jet latitude, blocking frequency and overall circulation pattern over the Scandinavian sector in a variety of reanalyses and climate model ensembles. Both the number of blocked days, and the average jet location for summer 2018 were unprecedented in the reanalyses, and rare in climate model simulations. We found no robust evidence of past or future externally forced changes in summer blocking frequency over Scandinavia in model simulations, whilst trends in circulation analogs were also largely insignificant. Trends in jet latitude were dependent on the time period examined, models included and other analysis choices. Overall, we found no robust evidence for systematic trends in average or extreme years toward Summer 2018‐like conditions for any of the three indices, nor in the frequency of co‐occurring extreme northward jet latitude and high blocking frequency. We conclude that Summer 2018s circulation can likely be explained by internal atmospheric variability.

(IF 3.90; Q1) ; International audience ; Coastal ecosystems are subjected to an increasing number of anthropogenic drivers, including marine renewable energies and climate change (CC). These drivers can interact in complex ways, which may lead to cumulative effects (CEs) whose potential consequences on the ecosystems need to be addressed. We used a holistic approach—ecological network analysis (ENA)—coupled with a two-dimensional food web model—Ecospace—to conduct an ecosystem study of the CEs of CC plus the operation of an offshore wind farm on ecosystem functioning in the extended Bay of Seine (English Channel). Mapped ENA indices showed that CEs were not restricted to the wind farm area, i.e. where anthropogenic drivers are concomitant. CEs varied both in space and among ecosystem properties, displaying that ENA indices can distinguish between different cumulative pathways that modify ecosystem functioning in multiple ways. Moreover, the effects seemed to be tied to the structuring role of CC, and differed under the 2050 and 2100 conditions. Such changes resulted in stronger loss of ecosystem resilience under the 2100 conditions despite the benefits of the reef and reserve effects of the wind farm.

The new GHG calculator named SECTOR (Source-selective and Emission-adjusted GHG CalculaTOR for Cropland) is based on the IPCC Tier 2 approach for rice as well as other crops. The new features of SECTOR facilitate high flexibility in terms of entering newly obtained emission factors, easy data transfer from crop statistics for entering activity data and detailed specifications of GHG scenarios. A new procedure of entering frequency-based data on current water management practices was also developed. Moreover, the tool allows deviating from the 2006 IPCC Guidelines by considering field records with high background levels of N₂O emissions in the overall assessment of GHG emissions. This article assesses different applications of the tool, namely as add-ons to field measurements, for GHG calculation at national/sectorial scale and within measurement, reporting and verification of development projects. SECTOR is downloadable in the form of templates that can be used to develop custom versions with varying levels of disaggregated data entries at different scales. A case study for rice production in one Vietnamese province demonstrates the potential to display GHG results in combination with GIS. SECTOR can easily be adjusted to incorporate new emission factors and calculation procedures expected in forthcoming revisions of the IPCC Guidelines.

Abstract During the course of a severe accident in a Pressurized Water Reactor, pressurization of the containment occurs and hydrogen can be produced by the reactor core oxidation and distributed in the containment according to natural, mixed and forced convection flows induced by break flow, wall condensation and spray systems used in some reactors' containment to prevent overpressure. Because of these phenomena, water can be collected in the sump containment, inducing further heat and mass exchanges between the sump surface and the atmosphere. Considering the large volume of the reactor containment, LP (0D) codes are preferred to CFD calculations, which still remain a very challenging task to compute. The French IRSN has tested different tools for containment studies with lumped-parameter codes and the reference code is now ASTEC/CPA, so that mainly results of this code will be presented here. This paper focuses mainly on several IRSN tests especially developed for containment studies and the above mentioned thermal-hydraulical phenomena. The objective of this paper is to present the validations performed with LP codes on these different experimental tests. Experiments on the TOSQAN facility are considered.

Glaciers are retreating globally, and the resulting ice-free areas provide an experimental system for understanding species colonization patterns, community formation, and dynamics. The last several years have seen crucial advances in our understanding of biotic colonization after glacier retreats, resulting from the integration of methodological innovations and ecological theories. Recent empirical studies have demonstrated how multiple factors can speed up or slow down the velocity of colonization and have helped scientists develop theoretical models that describe spatiotemporalchanges in community structure. There is a growing awareness of how different processes (e.g., time since glacier retreat, onset or interruption of surface processes, abiotic factors, dispersal, biotic interactions) interact to shape community formation and, ultimately, their functional structure through succession. Here, we examine how these studies address key theoretical questions about community dynamics and show how classical approaches are increasingly being combined with environmental DNA metabarcoding and functional trait analysis to document the formation of multitrophic communities, revolutionizing our understanding of the biotic processes that occur following glacier retreat.

International audience; Photovoltaic-thermoelectric hybrid devices aim at harvesting the entire solar spectrum via both direct photovoltaic conversion and subsequent thermoelectric conversion of the heat generated in the solar cell. Oneemerging strategy to improve their efficiency is to implement a photothermal interface between the photovoltaiccell and the thermoelectric module. Modeling such a complex system (photovoltaic cell, photothermal interfaceand thermoelectric generator) to design an optimal architecture is a challenging task, as it requires to take intoaccount a large number of parameters in a multi-layered system, as well as the coupling between optical, thermal and electrical effects. To do so, we present here a multiphysics tool to predict the temperature distribution and power output of hybrid devices integrating a photothermal interface. Our model shows a good quantitative agreement with previous theoretical and experimental works from the literature using limited material parameters. We discuss the need for additional parameters for accurate modeling of experimental devices. We envision that our multiphysics modeling tool will be key for the design of optimal photothermal interfaces for efficient photovoltaic-thermoelectric hybrid devices.