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Do Mixed-Species Groups Travel as One? An Investigation on Large African Herbivores Monitored Using Animal-Borne Video Collars
No full textData and code have been archived in a publicly available Figshare deposit (https://doi.org/10.6084/m9.figshare.25568175.v5; Dejeante et al. 2024)International audienceAlthough prey foraging in mixed-species groups benefit from a reduced risk of predation, whether heterospecific groupmates move together in the landscape, and more generally to what extent mixed-species groups remain cohesive over time and space, remains unknown. Here, we used GPS collars with video cameras to investigate the movements of plains zebras (Equus quagga) in mixed-species groups. Blue wildebeest (Connochaetes taurinus), impalas (Aepyceros melampus), and giraffes (Giraffa camelopardalis) commonly form mixed-species groups with zebras in savanna ecosystems. We found that zebras adjust their movement decisions solely on the basis of the presence of giraffes, being more likely to move in zebra-giraffe herds, and this was correlated with a higher cohesion of such groups. Additionally, zebras moving with giraffes spent more time grazing, suggesting that zebras benefit from foraging in the proximity of giraffes. Our results provide new insights into animal movements in mixed-species groups, contributing to a better consideration of mutualism in movement ecology
Intraspecific variation and phenotypic plasticity of olive varieties in response to contrasting environmental conditions
No full textInternational audienceAssessing the extent of genotypic and phenotypic trait variation within a genetically diversified species is crucial to understanding how plants cope with environmental differences. We examine these components in Olea europaea L. europaea, one of the most widespread and diverse tree crops cultivated in the Mediterranean Basin, a region facing rapid climatic shifts with increasing summer drought. We compared trait values of 83 olive varieties from different Mediterranean countries, grown in two ex situ varietal collections with contrasting environments: subhumid and semi-arid climates. Ten leaf-, stem-and branch traits related to resource and water use were compared across 50 varieties within each site, and phenotypic plasticity was assessed for the 17 varieties common to them. Trait plasticity was assessed with the phenotypic dissimilarity index while varietal plasticity was assessed in multidimensional trait space with the multivariate plasticity index. Our results showed considerable phenotypic variability within (up to 59.54%) and between (up to 39.17%) sites. Varieties grown in semi-arid conditions were more conservative, showing denser leaves and wood, and thicker bark. Common varieties exhibited contrasting degrees of plasticity across traits, demonstrating that high plasticity for some traits does not necessarily imply overall plasticity. Additionally, varieties with conservative trait values were not less plastic than more acquisitive varieties. Varieties showed distinct phenotypic adjustments across sites, with trait variations indicating acclimation strategies to reduce water loss in the arid environment. Our results also suggest that acclimation to different environments occurs through the adjustment of multiple traits, complicating plasticity comparisons across varieties
The cost of fame: strong biases in comparative oncology of captive species
No full textComparative oncology is a rapidly expanding field that seeks to explain variation in cancer risk across species by examining trends between tumour prevalence and key risk factors such as body mass, longevity, life history traits, and mutation rates. These trends are then used to address fundamental questions in the field, including the discovery of potential novel anti-cancer therapies, improvements to species conservation efforts, and understanding how cancer has influenced the evolution of multicellularity. They thus must be robust. This study demonstrates that when estimated on captive species those trends are heavily influenced by their scientific and public popularity, and that accounting for this bias can substantially alter their direction and magnitude. Hence, we reanalysed published captive vertebrate datasets examining the associations between neoplasia, malignancy, and lethal tumour prevalences with body mass, longevity, life history traits, and germinal cells mutation rates. When we included proxies of species popularity in our analyses, the previously reported weak effect of body mass on tumour and malignancy prevalences disappeared entirely. Similarly, the previously reported positive relationship between germline mutation rate and cancer mortality was eliminated after controlling for popularity bias. For life history traits, the effect of clutch size on cancer neoplasia and malignancy prevalences in birds doubled in magnitude, and while the negative trend between gestation length and tumour prevalence in mammals was not greatly affected, our analyses revealed that baseline tumour prevalences were underestimated for popular animals. Finally, the previously observed association between hemochorial placentation and cancer mortality in mammals was eliminated when confounding variables were included. Collectively, these results demonstrate that current comparative analyses based on tumour prevalence in captive animals are heavily influenced by species’ scientific and public popularities. Future studies utilising such datasets should incorporate measures of species popularity as confounding variables to ensure more robust conclusions and misleading research directions
In-situ TEM investigation of thermomechanical fatigue of thick copper metallizations
No full text#57International audienceWe investigate the thermomechanical behavior of thick copper metallization on polyheaters which are chipsdedicated for stressing the thick copper metallizations found in high-end power electronic devices. The degradationmechanisms of these metallizations are known to span from surface roughening to crack formation, but theunderlying elemental plastic deformation mechanisms (dislocation activity, stress-assisted diffusion, …) remainelusive. Here, we have combined post-mortem TEM observations of such polyheaters that underwent ultra-fast300K heating cycles and in-situ TEM heating experiments up to 480°C. Both approaches converge to estab lishthat the dislocation microstructure inside the grains is only slightly modified over these cycles and thus thatdislocation-based plasticity cannot explain the crack formation and propagation, along with surface rougheningobserved in these Cu metallizations
Evidence of Geological Control on the Hydrological Response of Tropical Volcanic Catchments
No full textInternational audienceThe aim of this study is to assess the key drivers of runoff generation in permeable volcanic catchments, and notably the role of geology. Therefore, the hydrological response of 28 catchments located on the tropical volcanic Island of la Réunion, characterised by strong climatic forcing and geological contrasts, was studied. High‐frequency measurements (15‐min time step) of radar rainfall and discharge records over the 2014–2022 period were analyzed to develop a hydroclimatic database including 4591 storm‐flood events. At the annual scale, results show regional patterns in the rainfall‐runoff relationship, associated with the geological age and the local climate. Our results provide evidence of windward/leeward and geological effects on hydrological response at both the annual and flood event scales, with a significant correlation between the event‐scale runoff coefficient and annual rainfall. Combined with a statistical analysis of the data, including the application of a random forest algorithm, results suggest the importance of antecedent saturation conditions, preferentially occurring on the older and more weathered geology, while younger geology displayed a more episodic pattern. This study contributes to increasing our understanding of the hydrological behaviour of tropical volcanic catchments, by analysing the relative importance of climate and geology in controlling the catchments' hydrological response, which may help improve water management and flood prediction
Lost in navigation? Ensuring living lab frameworks stay on course with local needs
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/615244/) * Autres projets (id;sigle;titre): ;Santés-Territoires;(EU) Projet Santés-Territoires//International audienceParticipatory modeling approaches, particularly those rooted in Companion Modeling (ComMod), are often credited with initiating socio-environmental transformations. Examples from Zimbabwe (Perrotton et al. 2017) and Burkina Faso (Daré et Venot, 2016) illustrate how these methods have facilitated engagement between stakeholders, sometimes leading to institutional changes over extended periods. However, the effectiveness of such approaches is contingent on their alignment with local realities and pressing challenges. The question remains: who holds the compass in these participatory frameworks? Do researchers, institutions and players succeed in abandoning their agenda? A case study from the Lake Guiers region in Senegal highlights the tensions between knowledge production, local agency, and transformative action. After several years of engagement with local communities through participatory workshops, a pivotal moment occurred in different arena : when a doctoral student presented her findings on hazardous chemical pollutants in the lake's water, when allochtone populations spoke out against their refusal to respect fishing restrictions face to face with native fishermen (Delay et al. 2023). Unlike previous discussions on ecosystem management, which were perceived as peripheral to daily survival, this revelation directly impacted livelihoods, exposing communities to immediate and invisible risks. The local response—calls for awareness campaigns and regulatory interventions—raised deeper questions about the adequacy of conventional participatory approaches. How can living lab models move beyond knowledge dissemination towards tangible systemic transformation? How can scientific findings generate experiential urgency rather than passive information? Recent scholarship suggests that for knowledge to trigger action, it must engage stakeholders not just intellectually/abstract, but affectively — a concept referred to as "affective knowing" (Hertz et Bousquet 2025). This perspective challenges traditional scientific detachment and underscores the need for transformative science that actively catalyzes change rather than merely observing it. A more reflexive and adaptive governance model is necessary—one that situates knowledge within local dispositifs (assemblages of discourses, institutions, and power structures). Rather than assuming that participatory models inherently lead to transformation, they must be reconfigured to align with the strategic urgencies of a given territory. This shift demands a reconsideration of the role of scientists in participatory governance: are they facilitators, guides, or interveners? By embedding participatory models within affective and political landscapes, living labs in Senegal and beyond can become true engines of systemic change rather than passive spaces for stakeholder dialogue
No attenuation of fish and mammal biodiversity declines in the Guiana Shield
No full textInternational audienc
Insect-habitat-plant interaction networks provide guidelines to mitigate the risk of transmission of Xylella fastidiosa to grapevine in Southern France
No full textInternational audienceXylella fastidiosa (Xf) is a xylem-limited bacterium that has been recorded in several European countries since its detection in 2013 in Apulia (Italy). Given the prominence of the wine industry in many southern European countries, a big threat is the development of Pierce's disease in grapevines. Yet, the insect-habitat and insect-plant interaction networks in which xylem feeders, possible vectors of Xf, are involved around European vineyards are largely unknown. Here we describe these networks in three key wine-growing regions of southern France (Provence-Alpes-Côte d'Azur, Occitanie, Nouvelle-Aquitaine) to identify primary xylem feeder habitats, and assess their specialization degree at the habitat, plant family, and plant species levels. A total of 92 landscapes (and 700 sites) were studied over three sampling sessions in the fall 2020, spring 2021, and fall 2021. Among the habitats sampled, meadows hosted the largest xylem feeder communities, followed by alfalfa fields. Vineyard headlands and inter-rows hosted slightly smaller xylem feeder communities, indicating that potential Xf vectors thrive near crops. Grapevines hosted few xylem feeders, suggesting rare but possible transfer to vulnerable crops. Philaenus spumarius, Aphrophora alni, Lepyronia coleoptrata, and Cicadella viridis were all similarly generalists at the habitat, plant family or plant species level. The only specialist was Aphrophora grp. salicina, which was restricted to riparian forests and to Salicaceae. Neophilaenus spp. were extremely specialist at the plant family level (Poaceae), but rather generalist at the habitat and plant species levels. All 1017 insects screened for the presence of Xf tested negative, showing that Xf is not widespread in the studied regions. Our study provides new basic ecological information on potential vectors of Xf, especially on their specialization and feeding preferences, as well as practical information that may be relevant for the design of epidemiological surveillance plans.which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</div
Migraine management in Lebanon: Assessing economic, clinical and digital perspectives on patient care and innovation
No full textInternational audienceIntroduction:Migraine care in Lebanon faces substantial challenges amid the ongoing economic crisis. Research remains limited to university populations and lacks comprehensive analysis of treatment patterns, costs, and socioeconomic impacts. This study aims to examine migraine's financial burden, assess patient well-being, analysetreatment cost-effectiveness, investigate medication quality awareness, and evaluate digital health acceptance among Lebanese migraine patients. The combination of medication shortages, rising healthcare costs, and diminished access to care makes this research particularly timely and relevant for healthcare planning in Lebanon.Method:This cross-sectional study will survey migraine patients across Lebanon using validated instruments including MIDAS, migraine-specific quality measures, EQ-5D-5L, LMAS-14, PHQ-9, and technology acceptance assessments. Data on healthcare costs, productivitylosses, treatment efficacy, quality of life, medication quality perceptions, and digital literacy will be collected and analysed through economic modellingand multivariate statistical approaches. The study will recruit participants from diverse geographic regions and socioeconomic backgrounds to ensure representative findings. Both preventive and acute treatment strategies will be evaluated, with particularattention to the impact of medication availability and quality concerns during the economic crisis. The Global Assessment of Migraine Severity scale will provide a standardisedmeasurement of disease burden, while willingness-to-pay assessments will establish economic thresholds for treatment value. Results:Expected outcomes include comprehensive documentation of migraine's economic impact across socioeconomic groups, insights into relationships between treatment adherence and outcomes during economic hardship, baseline data on digital health readiness, and cost-effectiveness comparisons between antimigraine therapies to inform clinical decision-making in resource-constrained environments. The study will quantify both direct medical costs and indirect productivity losses, identify socioeconomic barriers to effective treatment, and assess patient knowledge regarding counterfeit medications in the context of medication shortages. Results will establish the relationship between migraine frequency, severity, and economic burden, with stratification by socioeconomicstatus, geographic region, and access to healthcare resources. Conclusion:This research will address critical gaps in migraine management in Lebanon, providing evidence to inform policy decisions, optimiseresource allocation, and develop innovative care models suitable for economic crisis contexts. Findings will contribute to migraine management in similar resource-limited settings globally. Results will support the development of tailored interventions that consider both clinical effectiveness and economic feasibility, with potential applications in digital health innovations to improve migraine care despite resource constraints. By examining the complex relationship between socioeconomic factors, treatment access, medication quality, and health outcomes, this study will provide a foundation for developing resilient migraine care strategies during periods of economic instability. The digital health component will specifically explore affordable technological solutions to enhance patient monitoring, treatment adherence, and access to care in settings where traditional healthcare infrastructure is compromised