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Genetic Diversity and Effective Population Size of the Endangered Crozet Killer Whales
No full textInternational audienc
Pesticide mixture effects on physiological stress and morphology of growing wild nestlings
No full textInternational audienceSynthetic pesticides may pose a risk to non-target organisms, notably farmland birds, through their hazardous effects on life-history traits, but their impacts on growth and physiological stress have never been assessed in natura. We investigated these effects on skeletal growth, mass gain, body condition and physiological stress (basal and stress-induced corticosterone secretions) of 35 nestlings of Circus pygargus, a farmland apex predator, blood-sampled twice during their development. We found contamination levels ranging from 0 to 9 pesticides detected out of the 116 searched. We observed an age and sex-dependent pattern of pesticide mixture effects on nestlings’ growth and baseline corticosterone. Males (≤17 days old) having shorter tarsus when their pesticide load was high while this was found in older females (≥18 days old). Higher pesticide loads were linked to poorer body condition of young nestlings irrespective of their sex. Similarly, depressed corticosterone secretion was found in more contaminated young nestlings, and in females irrespective of their age. These alterations observed in young nestlings are caught up later during their development. No relationship between contamination levels and stress-induced corticosterone was found. Including other life-history traits would provide more information on other stress endpoints and potential energetic trade-offs between an active defence against pesticides and important functions of the organism
Towards higher predator ecoregionalisation of the pelagic zone in the subantarctic and subtropical Indian Ocean
No full textInternational audienceNumerous seabird and marine mammal species occur, often in high abundance, in the subtropical and subantarctic zones of the southern Indian Ocean. They breed, moult and rest at French, South African and Australian islands in the region and forage at sea in areas including the Exclusive Economic Zones of these nations, Areas Beyond National Jurisdiction and also the area to which the Convention on the Conservation of Antarctic Marine Living Resources applies. Information on the at-sea distribution of these species is important for understanding ecosystem patterns and processes in the region, and is a key component of any spatial conservation and management frameworks. Information on the distribution of marine predators is widely used to define priority areas for conservation and management, with several such initiatives already having been implemented in the extended Southern Ocean. Seabird and marine mammal distribution has been studied mainly using two methods: animal-borne biotelemetry/biologging and at-sea sighting records. Here, we give an overview of data on the distribution of marine mammals and seabirds -collected mainly through long-term tracking programmes at French and South African islands -with the aim of identifying data sources that can inform pelagic ecoregionalisation to support spatial conservation and management planning in this region. We identify priorities for further distribution data collection related to life-history stages, sites and species and we identify broader challenges for understanding marine predator distribution in this region, towards spatial conservation and management planning
Linking differences in personality to demography in the wandering albatross
No full textInternational audiencePopulation dynamics are shaped by individual differences. With a good understanding of the relationships between individual differences and vital rates, population models can be improved to yield more realistic and detailed demographic projections. Personality, i.e., consistent individual differences in behaviour, is expected to shape individual differences in performance. Yet, an empirical quantification of its impact on population dynamics is currently lacking. Here, we developed and analysed a three-dimensional hyperstate population model that accounts for three sources of individual differences simultaneously in its structure: age, breeding state and boldness as a measure of personality. We parameterized our model using empirical demographic and boldness data on the wandering albatross ( Diomedea exulans ) population from the Crozet archipelago. We conducted sensitivity analyses to quantify the relative importance of boldness. We then simulated scenarios of increased strength of relationship between boldness and three vital rates (survival, breeding probability and breeding success) to explore conditions under which shifts in boldness distribution could be observed in the future. We showed that the sensitivity of population growth rate to changes in vital rates followed the normal distribution of boldness within the population. Indeed, population growth rate was much less sensitive to changes in the vital rates of extreme shy or bold individuals, compared to that of individuals of intermediate boldness. Overall, sensitivity of population growth rate was greater for survival than reproductive rates across all three dimensions. Our simulations showed that increasing the strength of the relationship between boldness and survival would yield the greatest shift in boldness distribution over time compared to breeding probability and breeding success. However, shifts in boldness distribution appeared constrained by the low heritability ( < 0.2) value and the large variance in boldness in this population. Our study provides an important contribution to our understanding of the role of personality in shaping the population dynamics of wild species. In the face of global change, our approach offers a promising avenue to predict the potential for behavioral adaptation. More generally, our approach may help to unravel the complex interplay between individual variations in any (or many) traits and population dynamics
L’usage du jeu sérieux dans le débat public : le cadre de jeu contribue-t-il à nourrir le débat sur les éoliennes en mer en Nouvelle-Aquitaine ?
No full textInternational audienceLa commission particulière du débat public portant sur les éoliennes en mer en Nouvelle-Aquitaine a fait le choix, pour la première fois dans l’histoire du débat public français, d’avoir recourt aux jeux sérieux. Afin d’analyser comment les jeux sérieux peuvent venir nourrir le débat, nous mobilisons les trois figures du débat proposées par Jean-Michel Fourniau en 2021. Nous montrons que les jeux sérieux, aussi bien en ligne que de plateau, peuvent à la fois enrichir la consultation, délibération, et consultation, sous conditions. Une réflexion préalable sur la manière d’insérer les jeux dans le débat et de les concevoir, notamment au travers d’une co-construction avec les différents acteurs du débat apparaissent comme des pistes d’amélioration pour l’usage des jeux dans le cadre du débat public. Dans cette perspective, nos conclusions invitent la communauté scientifique à poursuivre les recherches sur les différents supports d’apprentissage d’une communication complexe
Microbial biomass – not diversity – drives soil carbon and nitrogen mineralization in Spanish holm oak ecosystems
No full textInternational audienc
An analytical study of the impact of glazed vs diffuse facades on solar trapping with detailed directional radiation model
No full textInternational audienceThe optical properties of building envelopes govern the inward and outward energy fluxes of a city; and therefore play a major role in urban overheating due to solar trapping. High reflectance (cool) materials have demonstrated a reduction in surface temperature of roofs with a high sky view factor, but their effects are limited to the upper floors of the buildings. To address the root cause of solar trapping, we must focus our attention on facades and roads, as these are the surfaces that contribute to multireflections in densely populated areas. We will showcase the interrelation between the shortwave optical properties of facades and the leading reflections within the canyon.We have developed an analytical urban canyon model that integrates a detailed angular shortwave radiation description of materials. We aim to quantify the impact of the optical properties of building facades on solar trapping by analyzing the directionality of their reflections. We track the irradiance reflected toward the road and toward the buildings, as they will affect pedestrian thermal comfort and building cooling needs, respectively. We consider traditional materials (lambertian and specular) to evaluate the current situation, and innovative materials (retroreflective) to envision solar trapping mitigation strategies. Simulations are performed with an hourly time step for a year time period.To verify the consistency of the model, we present the results for a mediterranean compact midrise neighborhood (H/W =1). During summer, for East-West facade orientations, glazed facades contribute to a 15 % increase of ground peak irradiance (equivalent to 85 W/m 2 ) compared to typical lambertian facades. The contribution of solar irradiance to thermal stress is evaluated with temperature sol-air indicator. Specular canyons result in a rise of 2 • C in peak sol-air temperature. For a typical meteorological year, specular facades increase by 11 % (155) the sol-air degree-hours above 26 • C, and increase by 132 % (145) the degree-hours above 40 • C compared to lambertian facades. Future studies will focus on measuring the impact on thermal comfort and building energy performance at neighborhood scale.</p
Modular green walls: A sustainable architectural solution for energy efficiency in oceanic climates
No full textInternational audienceRecently, green walls have increasingly been incorporated into building designs. They present a sustainable solution for both new constructions and retrofitting of existing buildings by reducing cooling energy requirements and enhancing overall thermal performance. However, there is limited information on the impact of living wall systems on building environments and their thermal performance in oceanic climates. This study fills this gap by assessing the thermal performance of modular living walls in La Rochelle, France, characterized by an oceanic climate. A prefabricated modular wall was installed on a house-like rectangular block, while a similar block without plant cover was used as a reference. External surface temperatures were measured to assess the effectiveness of the green wall in providing thermal insulation and its potential as a passive design strategy. The results revealed that the green wall significantly reduced surface temperatures by up to 15 °C compared to the reference wall during peak hours. Additionally, a numerical analysis was performed on a three-story building to compare its energy demands with and without green walls. The results indicate that incorporating green walls on the east and west façades notably enhances indoor thermal conditions, achieving a reduction in cooling load of approximately 64.38 %
Floodplain and channel restoration challenges in the Middle Ebro River.
No full textInternational audienceThe Ebro River is a large Iberian watercourse that develops an extensive floodplain in its middle reach with frequent floods and flooding processes. Fluvial dynamics have been stabilised by regulation and defence works. The flood risk management paradigm has now been changed and some nature-based solutions are being implemented within the framework of the LIFE+ Ebro Resilience strategy and project. With a large interdisciplinary scientific team, the SEDEXCHARE Project evaluates this change in flood risk management from a hydromorphological and river restoration perspective. The achievements so far are scarce in restoration, but important in risk management. It is explained in which line actions should be increased to recover the river dynamics, proposing a territory of freedom for the river. Learning lines are also defined from the current diagnosis for a context of climate emergency and increase in extreme events. The recovered health of the river will provide territorial resilience to the floodable space, which includes population centres, agricultural uses and natural spaces
Towards Explainable Clustering in Process Mining and Sequential Pattern Mining: A Formal Framework
No full textInternational audienceIn this paper, we propose a unified framework to enhance the explainability of clustering results by bridging methodologies from Trace Clustering in Process Mining and Sequence Pattern Mining. Our approach normalizes a common representation that transforms event logs and trajectories into structured sequences, ensuring consistency across sequential data types. We first introduce a systematic process for converting raw data into structured sequences, allowing for a coherent analysis of logs and trajectories. We then explore various clustering techniques, including Trace Clustering in Process Mining, Sequential Pattern Mining, and the GALACTIC approach, emphasizing their role in uncovering interpretable behavioral patterns. Through real-world dataset examples, on which we conducted behavioral pattern extraction studies, we demonstrate how integrating these methodologies enables a more comprehensive understanding of sequential data. Furthermore, we construct an event log and derive a process model from clusters obtained via Sequence Pattern Mining, illustrating how specific patterns contribute to cluster emergence. This structured approach enhances interpretability and provides a foundation for future research on explainable clustering