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Revisiting EELS Fine Structure Analysis in Zircon as a Tool for Interpreting its Structural Evolution into a Disordered System
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Sterile Insect Technique in a n-patch system with Allee effect and mass trapping: modeling, analysis and simulations
No full textThe sterile insect technique (SIT) is a biological control method aimed at reducing or eliminating populations of pests or disease vectors. This technique involves releasing sterilised insects which, by mating with wild individuals, will reduce the target population. In this study, we take into account the spatial dimension by modelling the pest/vector population as being distributed over several plots, with wild insects and sterile insects migrating between these plots. The main objective is to identify the critical plots for intervention, using the network connectivity and potential intervention constraints.Using results from monotone systems theory, we first derive a sufficient condition guaranteeing the elimination of the wild population through SIT, which relies on the sign of the Perron value of a certain Metzler matrix. When an Allee effect is naturally present, releases are finite in time, and an upper bound of the control time is provided. We then formulate an optimisation problem aimed at minimising the total daily number of sterile insects released to ensure population elimination. We focus in particular on the oriental fruit fly, which significantly impacts mango orchards in La Réunion.Through numerical simulations, we illustrate our theoretical results and study different scenarios, including some where releases are limited to certain orchards. Indeed, when implementing SIT in the field, some owners may be reluctant to allow releases on their property. We also consider additional control by mass trapping, which can affect the sterile insects entering trapped areas, and show that although it increases the critical number of sterile insects to be released daily, it reduces the duration of the SIT program. Mass trapping may thus decrease the total number of sterile insects released over the entire elimination program.</p
Can inverse calibration help improving process-explicit species distribution models?
No full textSimulation outputs, together with the code to reproduce the analysis and figures in this study, are available on GitHub at https://github.com/vvandermeersch/contrast_calibrationsInternational audienceProcess-explicit models (PEMs) are expected to provide reliable projections of species range shifts because they explicitly model the biological mechanisms that drive species responses to climate.However, their application is often limited by the need for diverse and detailed datasets, which are only available for a limited number of species. Inverse calibration has been identified as an avenue to help calibrate PEMs for many species, but it is still unclear whether it can provide biologically meaningful parameter estimates.Here, we investigated the potential of inverse calibration techniques to improve the accuracy of PEMs. We examined the discrepancies in parameter estimates obtained by classical and inverse calibration approaches. We evaluated two inverse calibration strategies: (i) calibrating all parameters simultaneously and (ii) focusing only on critical parameters. We assessed the realism of the obtained parameter estimates and the simulated processes by comparing them with measurements and observations across Europe. We show that when the entire model is calibrated at once, the model structure alone may not sufficiently constrain parameter estimation, leading to unrealistic parameter values. However, selective application of the inverse calibration approach---focusing on critical parameters---can improve model performance while still simulating realistic biological mechanisms
Stabilisation inattendue, induite par la pression, de l'état de haut spin du fer(II) dans un réseau métallo-organique
No full textInternational audienc
OntoPFAS : Ontologie des PFAS et de leur exposition
No full textMISTEA - Axe informatiqueInternational audienceLa construction d'ontologies est une des premières tâches dans le domaine de la représentation des connaissances. Elle reste très pertinente aujourd'hui, grâce à l'expressivité des langages formels, qui permettent encore d'explorer et de découvrir des connaissances. Pendant des décennies, la communauté a développé des méthodologies pour la construction manuelle d'ontologies, et plusieurs classifications de celles-ci ont été proposées. Dans cet article, nous présentons une méthodologie de construction d'ontologie basée sur des méthodes existantes, et nous l'appliquons à la représentation du domaine des PFAS (Per-et poly-fluoroalkyle substances) et de leur exposition. Les PFAS sont des substances dont la structure chimique particulière les rend très résistantes et efficaces dans de nombreuses applications industrielles. Ils suscitent un intérêt croissant en raison de leur impact négatif sur la santé et l'environnement. Ce travail s'inscrit dans le cadre du projet interdisciplinaire DAE (Détection d'Anomalies Environnementales)
The Future of Whale Conservation: Harnessing Distributed Acoustic Sensing for Real-Time Monitoring
No full textInternational audienceWhale distribution is a key indicator of ocean health and ecosystem stability, highlighting the need for informed conservation efforts. Yet, current monitoring methods such as visual surveys or autonomous passive acoustic monitoring, lack the spatial and temporal resolution necessary for detailed and continuous surveys at scale.Distributed Acoustic Sensing (DAS) is a game-changing innovative technology that transforms optical fibers into a dense network of sensors for geophysical and acoustic measurements. By emitting laser pulses propagating along the fiber, DAS detects signals reflected back from various points along the cable, providing high-resolution spatial data, over tens of kms. At the cost of massive amounts of data that require fast, optimized algorithms, this technology can operate on any optical fiber, including the hundreds of telecom cables already crisscrossing the world’s oceans.In this presentation, we will illustrate how DAS implemented on seafloor cables along the French Mediterranean coast enables whale detection and localization. This innovative project aims to track the presence, migration patterns, and locations of whales, contributing valuable insights into their behavior and movement patterns. Moreover, with the ability to collect and process data in real-time opens up the possibility of sharing the cetacean locations with relevant stakeholders, including nearby vessels.This information can enable vessel operators to adjust their speed, thereby reducing the risk of collisions and protecting marine mammals from the impacts of human activities
Technical note: Flow cytometry assays for the detection, counting and cell sorting of polyphosphate-accumulating bacteria
No full textInternational audienceAbstract. In the context of the ecological sustainability of phosphorus, emerging evidence for the ubiquitous presence of polyphosphate-accumulating bacteria in natural environments invites efforts to reveal their roles in the biogeochemical cycle of phosphorus. This requires high-throughput methods to characterize their structure and dynamics in ecosystems. A promising strategy is to combine the staining of intracellular polyphosphate granules and their subsequent detection by flow cytometry, enabling rapid data acquisition. In this study, we evaluated the potential of this approach by testing various factors that could affect the efficiency and specificity of polyphosphate labeling. Most of our experiments were performed using the 4′,6-diamidino-2-phenylindole dye (DAPI). However, we also carried out a preliminary study using the synthetic fluorochrome JC-D7, a new selective fluorescent dye used for the specific labeling of endogenous polyphosphate in living cells. The assays were performed on Tetrasphaera elongata, a Gram-positive bacterium known to accumulate large amounts of intracellular polyphosphates. We also used six bacterial strains belonging to different phyla, in particular a Gram-negative bacterial strain belonging to the genus Pseudomonas, which is characterized by low levels of cellular polyphosphate. The potential of flow cytometry to quantify and sort polyphosphate-accumulating bacteria in complex environmental samples, including soil, freshwater and sediments, was also examined. Our tests provide useful information for the design of future experiments and highlight the potential pitfalls and limitations of detecting polyphosphate-accumulating bacteria using the cytometric approach. We also show that JC-D7 is a promising dye for achieving these objectives, particularly for enumerating polyphosphate-accumulating bacteria from environmental samples
How the Theia/OZCAR information system make data from the French OZCAR critical observatory network more FAIR?
No full textInternational audienceThe Theia/OZCAR Information System (IS) aims to facilitate the discovery and reuse of in-situ data documenting the continental surfaces collected by French research organizations and their foreign partners, historically managed and disseminated in different databases and portals built independently by different communities. This includes data from the 22 observatories of the French Critical Zone Research Infrastructure, OZCAR-RI, which document the different environmental compartments of the critical zone. Their data were historically documented and distributed by information systems that used their own vocabulary and format for sharing data. The challenge for the Theia/OZCAR IS (Braud et al. 2020) is to federate this heterogeneous data (more than 300 variables), managed by different communities, into a common system and make it FAIR (Findable, Accessible, Interoperable, Reusable ; Wilkinson et al. 2016) for both humans and machines. This effort that started in 2017 is a contribution to national and European ecosystems for sharing and analysing multidisciplinary Earth system data that are being set up. At national level, the Theia/OZCAR IS is part of the French Earth System Data Terra Research Infrastructure (RI), which aims to provide access and analysis services for data from the entire Earth system and to strengthen interdisciplinary research. It also plays a role in the national research and innovation program OneWater and its OneWater Data Platform, which aims to improve access and interoperability of water data from French research and operational services. At the European level, Theia/OZCAR IS contributes to eLTER-RI data catalogue. The Theia/OZCAR IS was co-constructed with the scientific community, data producers and IT teams involved in data management. The needs expressed by scientific users were to be able to discover data by variable name and to download data from different producers in the same archive, with harmonised formats. Data producers also expressed the need for statistical reports on data use and/or a monitoring dashboard interface. The system has been designed taking into account that the FAIR principles apply to both metadata and data. A common data model, called ”pivot model”, has been defined to harmonise and standardise the description of data between the different data producers, from the granularity of dataset down to observation (time series of a variable at one location) and to set up information fluxes between the observatories’ information systems and the Theia/OZCAR IS (Fig. 1). It is based on several metadata standards (ISO 19115, O&M, DataCite). The Theia/OZCAR thesaurus, a controlled vocabulary for variable names and objects of interest, has been developed to support efficient data discovery and interoperability services. Its objectives are: to enable a user-friendly data discovery service thanks to simplified variable names, to offer precise descriptions of observations thanks to detailed variable names, to enable the implementation of standardised data exchange services that requires concepts describing the act of observation (observed variable and characteristics involved in sampling). The Theia/OZCAR thesaurus is published on the Web according to the FAIR principles: It is formally described using knowledge representation language : it implements the SKOS and I-ADOPT framework ontologies (Coussot et al. 2024), which allows variable names to be broken down into atomic elements (with at least one Property being measured and one Entity being observed) and to make it easier to establish semantic alignments with terms from other international disciplinary thesauri (alignments with EnvThes and GEMET are carried out); It is indexed in a searchable resource with access for both human (skosmos interface) and machines (SPARQL endpoint); The vocabulary and each of its terms have unique persistent web identifiers; Metadata for the vocabulary (license, provenance) and the terms (definition, synonyms) are provided and are sufficiently precise to enable users to understand what each term means. It is formally described using knowledge representation language : it implements the SKOS and I-ADOPT framework ontologies (Coussot et al. 2024), which allows variable names to be broken down into atomic elements (with at least one Property being measured and one Entity being observed) and to make it easier to establish semantic alignments with terms from other international disciplinary thesauri (alignments with EnvThes and GEMET are carried out); It is indexed in a searchable resource with access for both human (skosmos interface) and machines (SPARQL endpoint); The vocabulary and each of its terms have unique persistent web identifiers; Metadata for the vocabulary (license, provenance) and the terms (definition, synonyms) are provided and are sufficiently precise to enable users to understand what each term means. The Theia/OZCAR IS consists of several parts (Fig. 2): a data ingestion module, and data access and discovery services including a terminology service. The data ingestion module enriches the observation information supplied by producers with an additional harmonised vocabulary. For data discovery and access, the Theia/OZCAR IS includes a data portal with faceted search. Data visualisation, and APIs for data download and usage statistics services are currently been developed. The download service will make it possible to select several observations from different producers and to download the data at once in two open, self-describing formats (CSV and NetCDF) from a object-based S3 storage repository. To ensure interoperability of data for machines, a standardised data catalogue service (OGC CSW) is already implemented and used by Data Terra RI’s data sharing systems. A standardised data exchange service based on SensorThings API is under construction. The observations and datasets are indexed in a searchable resource with human (data portal) and machine (OGC data catalogue service, SensorThings API) access and are described by rich metadata with a plurality of precise attributes. As the data and metadata refer to terms from a vocabulary that follows the FAIR principles, this contributes to the semantic interoperability of the data. Data license and data provenance are provided with the data. Improving the fairness of data involves not only implementing semantic and technical features, but also supporting communities to adopt FAIR practices. Seminars on Data Management Plans and open licenses have been organised to encourage data producers to describe their data management and documentation practices and to associate data with a clear license. Supporting communities as they move towards FAIR data, and providing them with the human resources they need to make progress, remains one of the major challenges of the project
Female house ownership drives the positive association between matriliny and women's health in Meghalaya (India)
No full textInternational audienceMatrilineal kinship, which traces descent through the mother's lineage, has been shown to have health benefits for both women and children, but the specific practices by which matriliny enhances female health outcomes remain unclear. In this study, we analyzed the 2015 Demographic and Health Survey data from Meghalaya, India (4,109 women, 809 men, 3,197 children), a region where matrilineal and non-matrilineal communities coexist with a mixed combination of post-marital residence and inheritance transmission. We considered two practices usually associated with matrilineal systems (i) female house ownership and (ii) matrilocal post-marital residence. We find no evidence for improved health with spatial proximity with kin. Instead, we demonstrate that female (vs. male) ownership correlates with substantial health benefits for women, including reduced risks of being anemic (OR = 0.72, SE = 0.093, p < 0.001) and underweight (OR = 0.59, SE = 0.135, p < 0.001), for men, albeit to a lesser extent, and for children. Boys and girls living in households owned by women are more likely to receive medical care when sick (+200 %). The associations between female house ownership and better health outcomes remain after adjusting for age, wealth disparities, geographical area, fertility, or time since last birth. These results suggest that in Meghalaya, female economic status is a key pathway for explaining diversity in health outcomes, providing novel insights to bridge the gender health gap
Décrire la parcelle et étudier l'arbre en forêt Le Fil Rouge, un projet pédagogique interdisciplinaire au master
No full textInternational audienceOuvert en 2021, le master Sciences du Bois aborde le bois depuis sa fabrication dans l'arbre jusque dans ses usages,matériaux ou molécules. Il est construit autour de 3 piliers : le choix de pédagogies actives, l'interdisciplinarité et lesouhait de construire des ponts entre la recherche académique et les entreprises de la filière forêt-bois