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Complete zooplankton size spectra re-constructed from « in situ » imaging and Multinet data in the global ocean
No full textPlankton size spectra are important indicators of the ecosystem state, as they illustrate the quantity of organisms available for higher marine food web and reflect multiple size-dependent processes. Yet, such measurements are typically biased by the available sampling methods, either disrupting fragile organisms or lacking good resolution (in size and/or time and space). In this study, we combined two of the most common approaches to measure zooplankton Normalized Biomass/Biovolume Size Spectra (NBSS) to calculate a complete zooplankton distribution for organisms larger than 1 mm. The reconstructed NBSS slopes appeared steeper and closer to those measured by the UVP5 (+7.6%) and flatter than those of the Multinet (- 20%) particularly in tropics and temperate latitudes. The overall gain in polar biomass was relatively small for reconstructed biomass compared to bulk estimates from Multinet (+0.24 mgC/m3 or +4.25%) and high from the UVP5 (+2.0 mgC/m3 or +53%). In contrast, in the tropical and temperate ecosystems, the gain in biomass was small for UVP5 (+0.67 mgC/m3 or +30.44% and +0.74 mgC/m3 or +19.59% respectively) and high for Multinet (+1.66 mgC/m3 or +136% and +3.4 mgC/m3 or +309% respectively). Given these differences, we suggest here to combine in situ imaging sensors and net data in any comprehensive study exploring key living players in the ocean ecosystem and their contributions to the biological pump
A call for a systemic approach to the development of cowpea (Vigna unguiculata) in Senegal
No full textThis volume follows on from the Rencontres Francophone Légumineuses (RFL) held in March 2024, organized by CIRAD, INRAE, Terres Inovia and Terres Univia, and co-organized by the Institut Sénégalais de Recherches Agricoles (ISRA). This unique event brings together all those involved in development, the supply chains and research into grain and forage legumes. It's an opportunity to exchange views, share knowledge and accelerate innovation around legumes. The RFLs focus on seed, forage and woody legumes, and aim to cover the diversity of production systems, as well as the diversity of uses: food, feed and non-food. Pulses are a major lever for meeting the global challenges of climate change and food and nutritional security. All over the world, they play a strategic role, providing nutritional benefits and ensuring protein and food sovereignty. The many species of pulses also represent a formidable breeding ground for food innovation.International audienceCowpea offers significant potential for sustainable West African agriculture. However to effectively promote a wider adoption on farms, it is crucial to understand the environmental, social, and economic factors that shape current farming systems. In Senegal, surveys reveal a stark contrast between the Sahelian Zone (SZ) and the Sudan-Sahelian Zone (SSZ). In the most water-constraint SZ, cowpea is a cash crop supported by public funding for synthetic inputs and improved varieties. Conversely, in the less water-constrained SSZ, cowpea is grown sparsely with millet, primarily for household and animal consumption, using minimal inputs. In both zones, farmers are more likely to cultivate cowpea on fields located further away from their homes. In SSZ, availability of high agricultural area and labor shortages also encourage its cultivation. SZ farmers value cowpea's positive effects on intercropped plants less than SSZ farmers. In both zones, farmers strategically cultivate a range of cowpea varieties to address diverse needs and strengthen their resilience against climate risks. The rapid expansion of cowpea in SZ has been accompanied by a loss of biodiversity and an increase in pest problems. In conclusion, effective cowpea development in Senegal necessitates a balanced approach: recommendations should be tailored to diverse farm strategies, valuing the preservation of agroecosystem biodiversity and ecological services as well as cowpea's commercial growth and income generatio
Revisiting remote sensing cross-sensor Single Image Super-Resolution: the overlooked impact of geometric and radiometric distortion
No full textAccepted for publication in IEEE Transactions on Geoscience and Remote Sensing.This work was partly performed using HPC resources from GENCI-IDRIS (Grant 2023-AD010114835)This work was partly performed using HPC resources from CNES Computing Center.In remote sensing, Single Image Super-Resolution can be learned from large cross-sensor datasets with matched High Resolution and Low Resolution satellite images, thus avoiding the domain gap issue that occurs when generating the Low Resolution image by degrading the High Resolution one. Yet cross-sensor datasets come with their own challenges, caused by the radiometric and geometric discrepancies that arise from using different sensors and viewing conditions. While those discrepancies can be prominent, their impact has been vastly overlooked in the literature, which often focuses on pursuing more complex models without questioning how they can be trained and fairly evaluated in a cross-sensor setting. This paper intends to fill this gap and provide insight on how to train and evaluate cross-sensor Single-Image Super-Resolution Deep Learning models. First, it investigates standard Image Quality metrics robustness to discrepancies and highlights which ones can actually be trusted in this context. Second, it proposes a complementary set of Frequency Domain Analysis based metrics that are tailored to measure spatial frequency restoration performances. Metrics tailored for measuring radiometric and geometric distortion are also proposed. Third, a robust training and evaluation strategy is proposed, with respect to discrepancies. The effectiveness of the proposed strategy is demonstrated by experiments using two widely used cross-sensor datasets: Sen2Venµs and Worldstrat. Those experiments also showcase how the proposed set of metrics can be used to achieve a fair comparison of different models in a cross-sensor setting
From Student Mobility to Labor Immigration: Professional Trajectories and “Paper Careers” of Moroccan Graduates in France
No full textInternational audienceFrom the application for a long-stay student visa to the submission of a legal status change request at the prefecture, this article traces the “paper careers” of Moroccan engineers and managers who graduated in France and chose to stay and work there. Despite holding advanced degrees and fitting the profiles sought after for so-called “shortage occupations” characterized by a lack of qualified labor, the professional integration of these highly skilled migrants into the French job market remains uncertain and far from guaranteed. Delays in obtaining residence permits or work authorizations often deprive them of opportunities matching their qualifications, keeping them in precarious employment situations. These administrative obstacles hinder their labor market integration, limit their mobility, and restrict their ability to advance into skilled jobs
Rôle de l’environnement linguistique dans l’apprentissage d’une langue étrangère : perception de l’accent lexical russe par les francophones
No full textInternational audienceEn observant les étudiants francophones s’exprimer en russe en classe, nous avons remarqué un certain nombre d’erreurs récurrentes liées au rythme du mot russe. Les difficultés à percevoir et, en conséquence, à produire l’accent lexical russe, pouvant frapper n’importe quelle syllabe, découlent principalement des différences entre les systèmes accentuels des deux langues. Faute d’expérience perceptive et articulatoire en russe, l’apprenant transfère inconsciemment les traits de sa langue maternelle à la langue apprise.Nous avons fait écouter des séries de mots russes hors contexte à 12 étudiants francophones en leur demandant d’indiquer la syllabe perçue comme proéminente dans chaque mot entendu. Parmi les résultats, globalement encourageants, une difficulté assez étonnante témoignant d’un traitement subjectif, conditionné par le français, consiste en la non-perception des syllabes finales allongées russes comme proéminentes. La perception d’oxytons de longueur différente (Moskva « Moscou », boroda « barbe », magnitofon « magnétophone », etc.) est émoussée par l’influence de la langue maternelle dans laquelle la syllabe porteuse de l’accent primaire est toujours finale et allongée. C’est un phénomène qui est ancré dans la perception d’un francophone et intériorisé comme constituant la norme. De ce fait, les syllabes finales proéminentes ne sont pas forcément perçues comme telles, contrairement aux syllabes accentuées en position non finale, qui, elles, attirent l’attention parce qu’elles rompent le rythme régulier. La bonne perception des proéminences non finales s’explique par le fait qu’en français l’accentuation non finale a une valeur subjective et un rôle d’emphase, tandis que le marquage final est automatique et cadentiel.Наблюдая за франкоязычными студентами, изучающими русский язык, мы отметили ряд характерных ошибок, связанных с ритмической структурой русского слова. Трудности в восприятии на слух и, как следствие, в реализации русского словесного ударения объясняются прежде всего различиями в просодических системах двух языков. В условиях недостаточной устной практики студенты бессознательно переносят характеристики родного языка на изучаемый.Мы предложили двенадцати франкоязычным студентам прослушать ряд изолированных русских слов и указать в каждом из них ударный слог. В целом, полученные результаты положительные, однако среди выявленных трудностей особый научный интерес представляет тот факт, что учащиеся не всегда воспринимают финальные слоги под ударением, сопровождающиеся удлинением гласного, как ударные. Восприятие таких слов, как Москва, борода, магнитофон оказывается затруднённым под влиянием родного французского языка, в котором ударение падает на финальный слог и сопровождается его удлинением. Это просодическое явление укоренено в перцептивной системе франкоязычного студента и воспринимается как нормативное. Именно поэтому финальные ударные слоги в русском языке могут вызывать затруднения – в отличие от ударных слогов в нефинальной позиции, которые привлекают внимание, нарушая ритмическую регулярность, свойственную французскому языку. Лучшее восприятие нефинальных ударных слогов в русских словах объясняется тем, что во французском языке нефинальное ударение имеет субъективный характер (выразительный, эмоциональный), в то время как финальное ударение носит автоматический ритмический характер
The Poverty Penalty of Rights-Claiming Work: A Hidden Barrier in Public Services and Public Goods
No full textPoverty is exacerbated by the invisible labor of rights-claiming, disproportionately borne by women due to exclusionary bureaucracies. This "administrative penalty" perpetuates inequality. Recommendations include systemic reforms (universal services, inclusive digitization), recognition of this labor, and transforming gender norms. Three questions this brief answers to, (i) why is rights-claiming a genuine form of work?, (ii) why does this burden fall disproportionately on women? , (iii) what can be done to address this inequity
Using informative priors to account for identifiability issues in occupancy models with identification errors
No full textInternational audienceNon-invasive monitoring techniques like camera traps, autonomous recording units and environmental DNA are increasingly used to collect data for understanding species distribution. These methods have prompted the development of statistical models to suit specific sampling designs and get reliable ecological inferences. Site occupancy models estimate species occurrence patterns, accounting for the possibility that the target species may be present but unobserved. Here, two key processes are crucial: detection, when a species leaves signs of its presence, and identification where these signs are accurately recognized. While both processes are prone to error in general, wrong identifications are often considered as negligible with in situ observations. When applied to passive bio-monitoring data, characterized by datasets requiring automated processing, this second source of error can no longer be ignored as misclassifications at both steps can lead to significant biases in ecological estimates. Several model extensions have been proposed to address these potential errors. We propose an extended occupancy model that accounts for the identification process in addition to detection. Similar to other recent attempts to account for false positives, our model may suffer from identifiability issues, which usually require another source of data with perfect identification to resolve them. As an alternative when such data are unavailable, we propose leveraging existing knowledge of the identification process within a Bayesian framework by incorporating this knowledge through an informative prior. Through simulations, we compare different prior choices that encode varying levels of information, ranging from cases where no prior knowledge is available, to instances with accurate metrics on the performance of the identification, and scenarios based on generally accepted assumptions. We demonstrate that, compared to using a default prior, integrating information about the identification process as a prior reduces bias in parameter estimates. Overall, our approach mitigates identifiability issues, reduces estimation bias, and minimizes data requirements. In conclusion, we provide a statistical method applicable to various monitoring designs, such as camera trap, bioacoustics, or eDNA surveys, alongside non-invasive sampling technologies, to produce ecological outcomes that inform conservation decisions
The Multi-Compartment Hg Modeling and Analysis Project (MCHgMAP): mercury modeling to support international environmental policy
No full textInternational audienceThe Multi-Compartment Hg (mercury) Modeling and Analysis Project (MCHgMAP) is an international multimodel research initiative intended to simulate and analyze the geospatial distributions and temporal trends of environmental Hg to inform effectiveness evaluations of two multilateral environmental agreements (MEAs): the Minamata Convention on Mercury (MC) and the Convention on Long-Range Transboundary Air Pollution (LRTAP). This MCHgMAP overview paper presents its science objectives, background, and rationale; experimental design (multimodel ensemble (MME) architecture, inputs and evaluation data, simulations, and reporting framework); and methodologies for the evaluation and analysis of simulated environmental Hg levels. The primary goals of the project are to facilitate detection and attribution of recent (observed) and future (projected) spatial patterns and temporal trends of global environmental Hg levels and identification of key knowledge gaps in Hg science and modeling to improve future effectiveness evaluation cycles of the MEAs. The current advances and challenges of Hg models, emission inventories, and observational data are examined, and an optimized multimodel experimental design is introduced to address the key policy questions of the MEAs. A common set of emissions, environmental conditions, and observation datasets is proposed (where possible) to enhance the MME comparability. A novel harmonized simulation approach between atmospheric, land, oceanic, and multimedia models is proposed to account for the short- and long-term changes in secondary Hg exchanges and to achieve mechanistic consistency of Hg levels across environmental matrices. A comprehensive set of model experiments is proposed and prioritized to ensure systematic analysis and participation of a variety of models from the scientific community
Chapter 16 - Habitat degradation impacts on marine fish
No full textInternational audienceThe ocean supports a wide range of economic activities, including the harvesting of food, shipping, seabed mining, offshore hydrocarbon exploration and exploitation, tourism, and recreation, among others, all of which have significantly contributed to habitat degradation of coastal and marine ecosystems. This has dramatically impacted ecosystem function and services provided by these habitats, with detrimental consequences for marine fish. Over 90% of fish species are impacted by at least one anthropogenic stressor operating indirectly via their habitat, and about 70% are impacted by two or more, chiefly among which are chemical pollutants, eutrophication, invasive species, noise, and physical habitat loss. Still, rebuilding marine life, including fish populations, could be realized if major pressures are mitigated
