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Les défis du débat sur la décolonisation de la santé mondiale francophone
No full textInternational audienc
Aboveground biomass dataset from SMOS L-band vegetation optical depth and reference maps
No full textInternational audienceAboveground biomass (AGB) is an essential component of the Earth's carbon cycle. Yet, large uncertainties remain in its spatial distribution and temporal evolution. Satellite remote sensing can help improve the accuracy of AGB estimates. In particular, the L-band (1.41 GHz) vegetation optical depth (VOD) derived from the SMOS (Soil Moisture and Ocean Salinity) mission is a good AGB proxy. Averaging the SMOS L-VOD over a year and linking it to an existing AGB map constitute a well-established method to derive a spatial relationship between the two quantities. Then, a temporal extrapolation of this spatial relation derives global and harmonized AGB time series from the L-VOD. This study refines this protocol by analyzing the impact of three factors on the AGB-VOD calibration. First, an analysis shows that ascending and descending VOD can be properly merged to estimate the AGB. Second, the use of a single global spatial relationship is preferred over several regional ones. Third, this new AGB dataset is compared with other published AGB datasets to assess the validity of the temporal extrapolation. The produced dataset provides vegetation biomass values up to 300 Mg ha -1 from 2011 onward. It shows more interannual variability than the other available time series and presents globally lower AGB estimates. In general, the resulting AGB is consistent with the AGB maps of the Climate Change Initiative (CCI) Biomass version 5 (average Pearson's correlation coefficient 0.87) and can be used in AGB studies. The AGB dataset has been produced from the Level 2 SMOS products with one global VOD-AGB relationship, mixing ascending and descending orbits. The AGB dataset, including the spatial bias, is open-access and the NetCDF files are available at https://doi.org/10.12770/95f76ff0-5d89-430d-80db-95fbdd77f543 (Boitard et al., 2024)
Petit excursus philologique sur un monument de Moret
No full textInternational audienceAmong the various monuments that adorn Moret-sur-Loing, one of the most elegant is a Renaissance façade dating from 1527 and known as the ‘François 1er Façade’. Several Latin quotations have been affixed to it. We'll be taking a closer look at one of them, which is now very incomplete and for which we're proposing a reconstruction.Parmi les divers monuments qui ornent Moret-sur-Loing, l'un des plus élégants est une façade Renaissance datant de 1527 et connue comme la "Façade François 1er". Plusieurs citations latines y ont été apposées. On s'attarde en particulier sur l'une d'elles, aujourd'hui très lacunaire, pour laquelle on propose une restitution
Parallels and discrepancies between non‐native species introductions and human migration
No full textInternational audienceBiological invasions and human migrations have increased globally due to socio‐economic drivers and environmental factors that have enhanced cultural, economic, and geographic connectivity. Both processes involve the movement, establishment, and spread of species, yet unfold within fundamentally different philosophical, social and biological contexts. Hence, studying biological invasions (invasion science) and human migration (migration studies) presents complex parallels that are potentially fruitful to explore. Here, we examined nuanced parallels and differences between these two phenomena, integrating historical, socio‐political, and ethical perspectives. Our review underscores the need for context‐specific approaches in policymaking and governance to address effectively the challenges and opportunities of human migration and harm from biological invasions. We suggest that approaches to studying the drivers of biological invasions and human migration provide an excellent opportunity for transdisciplinary research; one that acknowledges the complexities and potential insights from both fields of study. Ultimately, integrating natural and social sciences offers a promising avenue for enriching the understanding of invasion biology and migration dynamics while pursuing just, equitable, and sustainable solutions. However, while human migration is a clear driver of biological invasions, drawing on principles from biological invasions to understand past and current human migration risks oversimplification and the potential for harmful generalisations that disregard the intrinsic rights and cultural dynamics of human migrations. By doing so, we provide insights and frameworks to support the development of context‐specific policies that respect human dignity, foster cultural diversity, and address migration challenges in ways that promote global cooperation and justice. This interdisciplinary approach highlights the potential for transdisciplinary research that acknowledges complexities in both fields, ultimately enriching our understanding of invasion biology and migration dynamics while pursuing equitable and sustainable solutions
Variability in the impact of linear transportation infrastructures on gene flow in French wild ungulate populations
No full textInternational audienceContext: Linear Transportation Infrastructures (LTIs) are among the largest factors responsible for landscape fragmentation, in turn increasing population isolation. In this context, studies have mainly focused on a single species’ response to barrier elements and mitigation thereof. Yet, the implementation of conservation strategies to restore landscape connectivity may be challenging when multi-specific responses are not measured and fully considered.Objectives: We aimed to assess the effect of two different types of LTIs, a fenced highway and a navigation canal on gene flow in three ungulate species in Northeastern France.Methods:We genotyped 98 red deer (C. elaphus), 120 wild boars (S. scrofa) and 140 roe deer (C. capreolus) with species-specific microsatellite markers from 3 sampling sites located on either side of both LTIs considered in the study area. We assessed the continuity of gene flow using Bayesian clustering methods and a mapping approach to determine inter-individual genetic dissimilarity in relation to landscape characteristics.Results:Our study showed different impacts of LTIs on the gene flow of species belonging a priori to the same functional group. Genetic differentiation among red deer and wild boar sampling units was observed on either side of the highway, but no such differentiation was identified for roe deer. However, no genetic structuring was associated with the presence of the canal in any species.Conclusions: The impact of LTIs on gene flow in large species results from the structural characteristics of the infrastructure, and our study shows that mitigation measures should consider species-specific behaviors to facilitate the use of crossing structures and thus ensure gene flow across ILTs
Reducing the use of plant protection products and greenhouse gas emissions in arable farming systems in northern France (System-Eco+)
No full textThis issue follows on from the “Carrefour de l'innovation agronomique” dedicated to the results of DEPHY EXPE 2 projects - Systems using pesticides as a last resort: results and lessons from 6 years of experimentation.International audienceCrop protection and nitrogen fertilizers uses are the mainstays of large-scale cereal and industrial cropping systems in northern France. Biological and climatic effects call to design and evaluate cropping systems that cut the use of plant protection products by implementing counterbalancing agronomic levers aiming to maintain yields. An experimental set-up composed of 7 cropping systems located at the Estrées-Mons agronomic station (France) was monitored from 2018 to 2024. The experiment combined decrease in the use of plant protection products while improving the greenhouse gas (GHG) balance by reducing synthetic fertilization. The introduction of cropping systems designed to reduce the use of pesticides made it possible to achieve treatment frequency index (TFI) reductions of 70 to 100% without significantly affecting yields and while ensuring weed control. This also resulted in a significant reduction in fungicide and herbicide residues in the soil. The levers used to reduce the use of plant protection products have a neutral effect on greenhouse gas emissions, or even a favourable effect when leguminous crops are introduced into the succession to provide soil cover and balance the nitrogen balance
Condition assessment and best-practice handling guidelines for skate (Rajiformes) bycatch: Lessons from demersal longline fisheries in the Southern Indian Ocean
No full textInternational audienceElasmobranchs, including sharks, skates and rays, are often characterised by low reproductive rates, rendering their populations susceptible to declines in abundance caused by elevated mortality rates. While skates are occasionally targeted by commercial fisheries, they are commonly caught as incidental bycatch in demersal fisheries. The release of captured individuals that are still alive is often used as a management measure to prevent declines in skate populations. Upon capture, a visual assessment of skate physical condition is necessary to avoid discarding of dead or badly injured individuals. Good handling practices are also required to promote postrelease survival. Our study investigated skate handling practices and the condition assessment method of Patagonian toothfish longline fisheries operating in the Southern Indian Ocean. A total of 171 longline captured skates were photographed, and the images analysed by specialist veterinarians trained in elasmobranch health to characterise injuries and qualitatively predict the physical and physiological consequences of each injury type on skate post-release survival. We found 13 types of injury, 10 of which were attributed to the capture process. Among these injuries, two were deemed irreversible, prompting a recommendation to retain the individual at all times. The majority of the examined injuries ranged from superficial to severe, particularly in cases of mouth/jaw damage. Based on these results, we developed best-practice handling guidelines and condition assessments, in form of posters and a comprehensive video tutorial. They provide clear guidance for managers and longline fishing crew for addressing 1) the condition of individuals that should be retained or released at sea alive and 2) handling practices to minimise further injury prior to the release. The guidelines for handling practices and condition assessments developed here can also be easily adapted to manage skate bycatch in other longline fisheries
Flexible foraging strategies of a tropical seabird in the western Atlantic Ocean
No full textInternational audienceTropical oceans are typically oligotrophic but can feature productive environments, such as islands, which can promote high prey availability, influencing predators' foraging strategies in time and space. This study investigates interannual and sex-specific variations in the foraging ecology of the masked booby (Sula dactylatra) in the Fernando de Noronha Archipelago, western tropical Atlantic Ocean. During the 2017, 2018, 2019, and 2022 breeding seasons, blood from birds and muscle samples from regurgitated prey were analyzed for stable isotopes of carbon (δ13C) and nitrogen (δ15N). Simultaneously, birds were tracked with GPS devices and their dives were recorded by pressure sensors and later predicted by deep learning tools to estimate foraging areas. Tracking data revealed foraging areas eastward of the archipelago in all years, potentially driven by the Island Mass Effect. δ13C and δ15N values varied significantly across the four years, but isotopic niches overlapped, except in 2022. Mixing models estimated the fourwing flyingfish Hirundichtys affinis as an important prey source from 2017 to 2019, shifting to false herring Harengula clupeola in 2022. Simultaneously, foraging areas were closer to the archipelago in 2022, with shorter foraging trip duration and length. Stable isotope differences between sexes were occasional, with overlapping niches and foraging areas consistently across years. These findings showcase potential predictability in foraging areas, and also their interannual variability, suggesting shifts in prey availability and distribution around the archipelago. Our results highlight the ecological plasticity of masked boobies in tropical environments and their potential as monitors of fish community dynamics
Immigration, integration, and the informal economy in OECD countries
No full textThis article assesses the impact of immigrant and asylum seeker inflows on the size of the informal sector in host countries from a macroeconomic perspective. We use two indicators of informality provided by Medina and Schneider (2019) and Elgin and Oztunali (2012) combined with migration data from the OECD International Migration Database and data on asylum seeker flows from the UNHCR for the period 1997-2017. We estimate a first-difference model, instrumenting immigrant and asylum seeker flows by their predicted values derived from the estimation of a pseudo-gravity model. Results suggest that both immigrant and asylum seeker inflows increase the size of the informal sector at destination, but the size of the effect is very small: a one percentage point increase in the stock of immigrants as a share of population leads to an increase of the informal sector as a share of GDP of 0.05-0.06 percentage points. Unsurprisingly, the effect is about four times larger for asylum seeker flows, but remains economically insignificant. We investigate several potential channels, and find that integration policies do matter. We find no impact of imported norms or institutions, but rather that the effect is larger in destination countries with a large informal sector. A larger diversity in incoming flows is associated with a smaller impact on the informal sector. Finally, we document the dynamics with a VAR model
Phosphine→Borane‐Functionalized Pyrenes and Anthracenes
No full textInternational audienceThe functionalization of polycyclic aromatic hydrocarbons (PAHs) with N→B Lewis pairs, so‐called borylative fusion, has recently emerged as a simple and powerful means to modulate their electronic and photophysical properties thanks to the extension of the π system. Herein, we considered a new class of PAHs appended with phosphine→borane Lewis pairs and investigated pyrene as well as anthracene derivatives. In these compounds, strong P→B interactions are enforced geometrically, but the π‐system is not extended. Nevertheless, such P→B functionalization was found to significantly impact the optical and electrochemical properties. The P,B‐functionalized PAHs display noticeably reduced HOMO–LUMO gaps and enhanced fluorescence. Both the number and position of P→B units turned out to play a significant role