Due to their unique and size-tuneable properties, quantum dots (QDs) have become established building blocks for diverse applications, in particular in display and biotechnologies. For the visible range alternative materials to highly toxic Cd-based QDs exist (e.g., InP, AgInS2), but the near infrared (NIR) and shortwave infrared (SWIR) range is still dominated by lead- and mercury-based QDs (e.g., PbS, HgTe). This range is of particular interest for numerous applications such as night vision, smartphones, wireless optical communication, photon up-conversion etc. We identified indium antimonide (InSb) and silver chalcogenides (Ag2Se, Ag2Te) as highly promising materials for NIR QDs, combining wide spectral tunability and absence of toxic elements such as Cd, Hg and Pb. However, the synthetic chemistry of these materials is much more challenging than for more established QDs. We propose novel synthetic approaches aiming at high-quality InSb and Ag2X QDs as well as their core/shell structures (WP1). The electronic properties (energy level positions) of the obtained QDs will be assessed using photoelectron spectroscopy and they will be integrated into photoconductive devices to probe the spectral and temporal response and signal-to-noise ratio under near infrared illumination (WP2). To fully assess their potential as emerging NIR QDs, we will also investigate their stability, degradation mechanisms and toxicity profile in vitro (cell culture) and in vivo (plant models) (WP3). The objectives of PIQUANT are threefold: first, we target the synthesis of monodisperse core and core/shell NIR QDs in a wide size range. Second, we will evaluate their performance as active layer in NIR/SWIR photodetectors. Finally, we will assess the (eco-)toxicity using in vivo (plants) and in vitro models of the main target organs in humans.

In France, many pressures threaten diadromous species and lead to their decline, some being even in danger of extinction. Dampening pressures on these migratory species is thus of great concern for their conservation. To restore the aquatic continuity near dams, fishways and fish ladders are built to allow fish passage. However, these sites constitute bottlenecks frequented by lots of catfish Silurus glanis. Catfish is an alien species that, due to its very big size, is the only one able to predate these adult migratory species in rivers. On several rivers, catfish has been shown to predate up to 80% of migrators when they were going up the river to spawn, which considerably limits the efficiency of fishways and fish ladders. Among fishes, catfish hears excellently; typically, recreational fishermen hit the water surface with a specific wooden tool (« clonk ») to attract catfish. However, in intensive fishing areas, it has been reported that, on the contrary, the clonk triggered an escape response, highlighting the great learning abilities of this species. Our work aims to test the possibility to control catfish behaviour by phonotaxis and to apply it to its local management. At first, different kinds of sounds (eg congener vocalizations, clonk) will be collected in an experimental natural lake and in other ecosystems thanks to citizen science. Once it will have been checked that they specifically target catfish, the most attractive of them will be used to control catfish behaviour. This consists in attracting catfish with these stimuli, and then generate an unpleasant experience (a light electric shock for example), so that catfish learns to associate the attractive acoustic stimuli to a noxious experience; catfish should then escape just by hearing the initially attractive stimuli. Operant conditioning and its efficiency will be assessed in an experimental natural lake where catfish individuals are continuously tracked. Once the method will be well tuned, it will be tested in real conditions near a fishway in presence of diadromous species. The method will be refined to become a management tool, targeting specifically catfish and limiting its predation pressure on endangered migratory species at sites with high stakes.

For thousands of years, the interaction between the human nutrition, genome and microbiome led populations to be biologically adapted to certain diets. Although this entangled coevolution is a key aspect of sustainable and healthy alimentation, the majority of our scientific knowledge is restricted to European populations, increasing inequality between Western and developing countries. In Oceania, Papua New Guineans (PNG) are the descendants of a 50,000 years long interaction with a unique environment from which they extracted specific food resources. They managed their environment until the independent invention of agricultural practices around 8,000 years ago. Despite this intricate history with local resources, modern PNG populations often suffer from malnutrition especially in urban places where industrialized food is mostly consumed. The NUTRIOCEO project is built on the ambition to characterize in depth the genome-microbiome-diet interaction in PNG, using a multidisciplinary approach combining expertise from nutritional anthropology, genomics, and microbiology. Based on a long-term international collaboration, we will analyse human genomic variants, oral and gut microbiome diversity and dietary data for 300 participants from PNG in rural and urban locations. The main objectives are (1) to characterize the genetic adaptations caused by historical changes in diets in PNG; (2) to determine the oral and gut microbial diversity in PNG and its link to diet; (3) to identify associations between genetic variants under selection and microbial species associated with diet; (4) to evaluate the impact of urban diet on the interaction genome-microbiome-diet. The NUTRIOCEO project will unveil coevolutionary mechanisms of important matter regarding human health in our era marked by climate changes and the problematic of the availability of alimentary resources.

Soil microorganisms are globally seen as a source of carbon (C) because of their central role in releasing greenhouse gases such as carbon dioxide (CO2) and methane. Certain bacteria and protists can consume atmospheric CO2 using diverse metabolic pathways, but they are presumed either to be rare community members or with insignificant CO2 assimilation capacities compared to plants. Yet emerging evidence shows that microbial CO2 uptake can contribute significantly to terrestrial primary productivity. Given that both microbial CO2 uptake and release coexist in soils, an enduring question is to which extent and under which conditions these microbial C processes counterbalance each other. Particularly, any decoupling among these coexisting microbial processes resulting from climate change is likely to have consequences for the whole-soil C balance, with unforeseen consequences for future climate conditions. MICE will tackle these questions in peatland ecosystems— a major terrestrial C pool. We will test how microbial CO2 exchanges with the atmosphere modulate peatland C dynamics under climate change. Specifically, this project aims to 1) probe the metabolic rates that underpin microbial CO2 exchanges; 2) Examine the biotic and environmental controls of microbial CO2 exchanges across space and time to make annual microbial CO2 budgets; 3) Perform experimental and modelling studies to reveal how climate change alters microbial CO2 exchanges and how these shifts could impact whole peatland C balance. To fulfil these aims, this work will utilize a powerful approach that harnesses multi-omics microbial analyses, microbial and ecosystem CO2 flux measurements, and biogeochemical analyses with geospatial and Land Surface modelling. The response of soil C to warming is still one of the great uncertainties in global C cycling. The achievement of this project will mark a step-change in understanding microbial processes surrounding the projections of peatland C emissions to the atmosphere, and address a critical research challenge of the Anthropocene in a key natural ecosystem: how climate change will impact soil C cycling by the soil microbiome?

From a perspective of sustainable development, the cities of tomorrow have to be more resilient and adaptive. Operational solutions are urgently needed to face ongoing and future climate changes, but also to reduce anthropic pressure on natural resources. In such a view, urban greenspaces are a key element of future cities as they imply the production of organic wastes – e.g. woody wastes - and also provide ecosystem services. To date, recycling by composting and biomethanisation are not well adapted to woody residues. Production of biochar (heating without O2) can consist in a valuable way to ecologically and economically valorizate these wastes. In addition, its incorporation into soils is now recognized as a valuable material to store carbon in soils and to promote soil functions such as water retention and belowground biodiversity. Hence, biochar can be a tool to recycle woody residues while promoting a new bioeconomic sector but also ecosystem services provided by soil from urban greenspace area. Yet biochar alone is unlikely to promote alone soil fertility in urban green spaces as a consequence of their intrinsic low nitrogen content. OPTISOIL proposes to grow nitrogen-fixing plants in these urban green spaces to counterbalance this limitation. This project aims to document the combined effect of the addition of biochar and N2-fixing plants on the functions of a degraded soil (e.g. technosol) and to estimate the ecological imprint and economic prospects related to these nature-based solutions. OPTISOIL will develop fundamental and applied research on the use and impact of biochar and N2-fixing plants on : (i) the biogeochemical cycle of the soil, in particular through the study of the degradation of biochar and of the factors controlling CO2 emissions at short and long time scales; (ii) soil water retention by coupling geophysical tools to propose a unique spatial and temporal field monitoring for such an experimental ; (iii) above-ground and below-ground life to determine additional carbon stocks but also changes in soil biodiversity, a substrate for numerous ecosystem services; (iv) the ecological footprint and the techno-economic impacts will also be evaluated in order to assess the sustainability of the proposed natural solutions and their potential for developing a new economic sector. Overall, according to its resolutely multidisciplinary approach, the OPTISOIL project will involve research aligning the interests of different scientific disciplines (organic geochemistry, geophysics, microbiology and economics) and of public and private stakeholders in the management of green spaces.