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Dispersal-induced growth or decay in a time-periodic environment. The case of reducible migration matrices
No full textInternational audienceThis paper is a follow-up to a previous work where we considered populations with time-varying growth rates living in patches and irreducible migration matrix between the patches. Each population, when isolated, would become extinct. Dispersal-induced growth (DIG) occurs when the populations are able to persist and grow exponentially when dispersal among the populations is present. In this paper, we consider the situation where the migration matrix is not necessarily irreducible. We provide a mathematical analysis of the DIG phenomenon, in the context of a deterministic model with periodic variation of growth rates and migration. Our results apply in the case, important for applications, where there is migration in one direction in one season and in the other direction in another season. We also consider dispersal-induced decay (DID), where each population, when isolated, grows exponentially, while populations die out when dispersal between populations is present
Mismatches between the current marine Natura 2000 network and seabird distributions call for enhanced protected areas off metropolitan France
No full textInternational audienceSeabirds are among the most threatened vertebrates, under pressure from fisheries bycatch, climate change, overfishing, and human disturbance. In France, demographic studies have highlighted adult survival as a key factor in population trends, which calls for large-scale marine conservation efforts. In this context, the Natura 2000 policy requires the designation of Special Protection Areas (SPAs) to protect seabirds under the Birds Directive. To assess the completeness of the French marine SPA network, data from aerial, boat, and coastal surveys, as well as tracking devices and distribution models, were collected for 57 seabird taxa. This data collection allowed the EU minimum criteria for a coherent SPA network to be spatially implemented, and the most ecologically valuable areas for seabirds around metropolitan France to be identified and prioritised, and overlaid with the current French SPA network and Marine Important Bird Areas (mIBAs) to identify potential inconsistencies. This analysis revealed seabird hotspots outside the existing ecological network, confirming some insufficiencies for coherent seabird conservation. Although data dependent, this analysis highlighted the limitations of using global proportion coverage to assess network coherence when coverage of biodiversity and abundance hotspots was not achieved. Furthermore, these results summarised the main target areas for policy makers to effectively improve seabird conservation around metropolitan France. In a context of increasing demands for marine spatial planning, improvements in this knowledge, the SPA network and conservation actions are required
How Children's Experiences and Perceptions of Their School Food Environment Influence Their Food‐Related Decisions In‐School in Urban Ghana
No full textInternational audienceSchool food environments play an important role in shaping children's food‐related decisions, including where and what foods to acquire and consume on a school day. In Ghana, evidence indicates that food environments in and around schools may limit healthy food acquisition and consumption behaviour. This study aimed to understand how children's experiences and perceptions of their school food environment influence food acquisition and consumption decisions. Data from 18 focus group discussions with children ( n = 157; aged 10–17 years) attending Public Basic Schools in the Greater Accra Region of Ghana were analysed, guided by the African urban food environment framework for creating healthy nutrition policies and interventions. Children's food decisions in school were found to be influenced by experiences and perceptions at multiple food environment levels: macro, physical and social levels in combination with individual‐level factors. At the macro level, exposure to food advertisements on television emerged as an influence on food‐related decisions. At the physical level, experiences and perceptions of environmental sanitation, food vendor hygiene practices, affordability, and food quality were consistently reported to influence decisions. Social‐level experiences including influence from friends/peers, family (mostly caregivers/parents) and social qualities of food vendors also shaped food‐related decisions. Caregiver/parental dietary advice was often linked to healthier acquisition and consumption decisions by children in school. The findings highlight the need for actions that work in synergy across multiple levels of the school food environment to create conditions that support children to acquire and consume healthier diets
Les zones arides et marginales du sud du Maghreb : un vivier d’opportunités pour un développement humain et territorial équilibré
No full textInternational audienceThe arid and marginal areas in southern Maghreb (Algeria, Morocco and Tunisia) constitute vast regions. Development challenges and the legitimate aspirations of the well-being of local populations must be managed in a context of acute constraints, such as structural water shortages or increased pressure on other natural resources (land, primary biomass, etc.). Based on the contributions to the thematic issue of the journal Cahiers Agricultures entitled “Agricultural systems in the arid zones of the Maghreb facing changes: actors, territories and new dynamics”, this introductory article allows us to understand these so-called marginal regions as places of production, innovation and resilience. A set of trans-disciplinary approaches were conducted within the framework of the Massire project. This project also initiated and monitored multi-stakeholder processes to generate knowledge co-production and promote co-learning. The work focused specifically on the palm oases of Ghardaïa in Algeria, Ferkla in Morocco and Kébili in Tunisia, but also on the mountain area of Mesmrir in the central High Atlas in Morocco and the region of Médenine in Tunisia. The scientific articles in this thematic dossier analyze different innovations, initiated by local actors in their diversity (young people, women, local leaders involved in promoting collective actions, etc.) or carried out collectively within the framework of multi-stakeholder processes. The articles highlight the strong potential of these innovations for greater territorial resilience, over time.Les zones arides et marginales du sud du Maghreb (Algérie, Maroc et Tunisie) constituent de vastes régions. Les enjeux de développement et les aspirations légitimes au bien-être des populations locales doivent y être gérées dans un contexte de contraintes aiguës, telles que la pénurie d’eau structurelle ou la pression accrue sur d’autres ressources naturelles (foncier, biomasse primaire, etc.). Sur la base des contributions au dossier thématique de la revue Cahiers Agricultures intitulé « Les systèmes agricoles des zones arides du Maghreb face aux changements : acteurs, territoires et nouvelles dynamiques », cet article introductif permet d’appréhender ces régions, dites marginales, comme des lieux de production, d’innovation et de résilience. Un ensemble d’investigations reposant sur des approches transdisciplinaires ont été menées dans le cadre du projet Massire. Ce projet a aussi initié et suivi des processus multi-acteurs en vue de générer une co-production de connaissances et de favoriser le co-apprentissage. Les travaux ont porté plus particulièrement sur les oasis à palmier de Ghardaïa en Algérie, de Ferkla au Maroc et de Kébili en Tunisie, mais aussi sur la zone de montagne de Msemrir dans le Haut Atlas central au Maroc et la région de Médenine en Tunisie. Les articles scientifiques constituant ce dossier thématique analysent différentes innovations, initiées par les acteurs locaux dans leur diversité (jeunes, femmes, leaders locaux impliqués dans la promotion d’actions collectives, etc.) ou portées collectivement dans le cadre des processus multi-acteurs. Les articles soulignent le fort potentiel de ces innovations pour une plus grande résilience des territoires, et ce, dans la durée
Bidirectional Translations Between Observational and Topography‐Based Hydrographic Data Sets: MERIT‐Basins and the SWOT River Database (SWORD)
No full textInternational audienceThe recently launched Surface Water and Ocean Topography (SWOT) Mission is expected to provide transformative observations of water surface elevation, width, and slope and produce derived estimates of discharge for global rivers along rivers in the SWOT River Database (SWORD). However, the hydrographic representation of rivers in SWORD differs from hydrography data sets commonly used for modeling purposes, such as Multi-Error-Removed Improved Terrain (MERIT)-Basins. Here, we develop links between the river networks of SWORD and MERIT-Basins (MB) to enable interoperability between SWOT data products and hydrologic modeling frameworks. This data set, termed MERIT-SWORD, identifies a subset of ∼277,000 global MB river reaches that most closely represent the location and extent of the SWORD river network and establishes bidirectional, one-to-many translations between reaches in the two hydrographic data sets. The MERIT-SWORD data set serves to unite SWOT observations with river routing models, allowing for the seamless and standardized assimilation of SWOT vector products into global river simulations and the provision of improved a priori discharge estimates for SWOT discharge computation. Plain Language SummaryThe Surface Water and Ocean Topography (SWOT) Mission observes the water surface elevation, width, and slope of river reaches described in the SWOT River Database (SWORD). The location and extent of rivers in SWORD differ considerably from other river network data sets that are commonly used for hydrological modeling such as Multi-Error-Removed Improved Terrain (MERIT)-Basins. Here, we present and publicly share the MERIT-SWORD data set which links rivers in SWORD to rivers in MERIT-Basins (MB), and vice versa. These links between river reaches in the two data sets can allow for model simulations to be used as a first guess for SWOT measurements, and for observations from SWOT to be easily transferred to hydrologic modeling frameworks based on the MB river network for data assimilation
Digitainability – une convergence entre numérique et pratiques agricoles durables est-elle possible ?
No full textInternational audienc
The contribution of small RNAs to the evolution of separate sexes and sex chromosomes in the plant Silene latifolia
No full textInternational audienceDioecy is a breeding system with separate females and males, where sex can be determined by sex chromosomes (for instance XY males and XX females). Dioecy is generally associated with the evolution of sexual dimorphism. In this study, we tested whether small RNAs (sRNAs) play a role in sexual dimorphism and sex chromosome evolution in Silene latifolia. We generated new data for female and male sRNAs and DNA methylation. We showed that sRNAs are most of the time female-biased in S. latifolia, suggesting the presence of the Y chromosome globally impacts the epigenome by diluting sRNAs genome-wide in males. We found limited evidence for the regulation of sex-biased genes by sRNAs, but we nonetheless identified a male-biased transcription factor that may potentially be regulated by sex-biased RNA-directed DNA methylation. This transcription factor might contribute to male traits, through the regulation of key factors in sex-determination and phenotypic sexual dimorphism. Finally, we compared female and male sRNA mapping along the S. latifolia sex chromosomes. We found that X and Y genes are targeted by significantly more sRNAs in males compared to females and PAR genes. Our results suggest that Y genes silencing following Y degeneration leads to the formation of sRNAs that can interact with both X and Y genes in males due to X-Y sequence homology. Our work calls for future investigation of the impact of these sRNAs generated from the Y chromosome on X gene expression in males
Locally-weighted-RoBoost-PLS: a multivariate calibration approach to simultaneously cope with non-linearities and outliers
No full textInternational audienceBackground: Partial Least Squares regression (PLS) is a widely used tool for predictive modelling, particularly when dealing with multivariate datasets with dependent variables exhibiting strong collinearities. However, when relationships between variables are non-linear or atypical data points have to be coped with, PLS calibration models may face challenges. In recent years, different variants of the original PLS algorithm have been proposed to overcome these limitations. On the one hand, several robust regression methods that down-weigh outlying observations during the model training phase like RoBoost-PLS have been developed to reduce the detrimental effect of outliers on the performance of PLS. On the other hand, local modelling approaches, like K-Nearest-Neighbours-Locally-Weighted-PLS (KNN-LW-PLS), have been designed to handle non-linearities by fitting for each new incoming sample a separate linear calibration model considering only its nearest-neighbours. Unfortunately, none of these strategies can address the two aforementioned problems simultaneously. This paper introduces a novel approach named Locally-Weighted-RoBoost-PLS (LW-RoBoost-PLS), that combines the strengths of both local and robust modelling methodologies in order to deal with non-linearities while mitigating at the same time the influence of outliers. Results: The performance of LW-RoBoost-PLS was evaluated on simulated and real industrial data (with this latter resulting from a continuous Acrylonitrile-Butadiene-Styrene ABS production process conducted at Versalis S.p.A.), both characterised by the simultaneous presence of outliers and non-linear relationships among measured variables. In the two case-studies investigated here, LW-RoBoost-PLS outperformed RoBoost-PLS and KNN-LW-PLS, achieving considerable reductions in the prediction error and prediction bias, which demonstrates that this technique permits to effectively overcome the limitations of the other approaches. Significance: This paper describes a novel multivariate calibration approach named LW-RoBoost-PLS, which provides a solution for predictive modelling in scenarios where outliers and non-linearities co-exist. LW-RoBoost-PLS simultaneously handles non-linearities and outliers by combining local and robust modelling strategies, leading to improved prediction accuracy and reduced bias
M1.9 Third Synchronisation Workshop Report
No full textThe Synchronisation Force workshops, annual series held between 2022 and 2024, brought together various stakeholders to periodically assess the progress in the FAIR-IMPACT focus areas. This Milestone concerns the 2024 workshop series. This Milestone demonstrates that FAIR-IMPACT, specifically Task 1.3 Synchronisation with EOSC Partnership and relevant projects and initiatives, organises an annual workshop series to monitor progress in FAIR practices across a wide range of EOSC initiatives and to disseminate such developments among the representatives of these initiatives.
