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High β‐diversity in fig wasp communities driven by species turnover in widely distributed Neotropical fig trees
No full textInternational audienceWasp communities associated with fig trees, Ficus spp., are a model system to investigate how local and regional processes shape biodiversity across large geographical ranges. We investigated the β‐diversity of fig wasp assemblages associated with three widely distributed Neotropical fig species – F. citrifolia, F. obtusifolia and F. pertusa – using 27 years of spatially extensive sampling across Brazil, Costa Rica and Ecuador. We quantified β‐diversity using the Sørensen index and its components of turnover and nestedness. For all three Ficus species, β‐diversity was high (0.87–0.90), driven primarily by species turnover (85–96% of β‐diversity). Wasp guilds, i.e. gall inducers, kleptoparasites and parasitoids, presented similarly high turnover values. Our results showed that life‐history traits play a role in the variation of β‐diversity, as gall‐inducing species are more host‐specific. In contrast, kleptoparasitic and parasitoid wasps are more likely to use multiple hosts. Mantel tests revealed that both total β‐diversity and the turnover component were often positively correlated with geographic distance, particularly for the most sampled fig species. Despite the exceptional dispersal capacities reported for several fig wasp lineages, our results suggest that competition for limited fig inflorescence resources, along with natural selection for local adaptation, can restrict species' geographic ranges, thus promoting higher levels of species turnover. These findings underscore the complex interplay between dispersal ability, local adaptation and competitive interactions in shaping the composition of fig wasp communities. Consequently, fig wasp systems present a compelling model for investigating the ecological and evolutionary processes driving biodiversity dynamics in specialized plant–insect interactions
Geographic variation in floral scent reinforces local pollinator attraction in the fig–fig wasp mutualism
No full textInternational audienceBackgroundVolatile organic compounds (VOCs) emitted during floral receptivity are crucial for attracting pollinators, especially in brood-site pollination systems. Geographic variation in floral scent can alter host recognition cues, potentially shaping pollinator behavior in obligate mutualisms such as the fig–fig wasp system. Understanding whether and how such variation affects pollinator responses is essential for assessing the stability of these interactions. Here, we investigated geographic variation in floral scent and pollinator responses in Ficus hispida, a dioecious species widely distributed in tropical Asia.Using dynamic headspace sampling and GC-MS, we characterized receptive fig VOCs from populations in South China, Southwest China, and South Thailand. Behavioral assays tested the responses of Ceratosolen marchali wasps from the South China Botanical Garden (SCBG) and Xishuangbanna Tropical Botanical Garden (XTBG) to local versus non-local fig odors.ResultsScent profiles differed significantly among regions, forming three distinct clusters. Although C. marchali was present at both sites, Y-tube experiments revealed that wasps responded only to odors from their local population.ConclusionsThis local scent specificity may reinforce population-level mutualisms and restrict long-distance pollinator movement. While such divergence could promote reproductive isolation among closely related wasp lineages, the mechanisms allowing cryptic species to coexist on the same host remain unclear. Overall, our results highlight the key role of chemical cues in shaping plant–pollinator interactions across different populations
Heat Acclimation During the Third Week of a Live-High-Train-High Training Camp Does Not Impair the Hematological and Perceptual Responses to Altitude.
No full textInternational audienceThis study investigated whether implementing heat training during the final week of a 3-week altitude training camp affects the hematological adaptations and variables monitored during chronic hypoxia. Twenty-three well-trained triathletes (19 males, 4 females) underwent 21 days of altitude training camp in spring (Live-High-Train-High, 1850 m). From day 14 to day 21, participants were split into two groups: a control group (HYPOXIA), which remained in the same condition, while the second group (COMBINED) had a ~1 h cycling session per day conducted in the heat (36°C ± 1°C, 40% ± 5% RH). Training load was the same for both groups. Hematological responses (including hemoglobin mass (Hbmass) and plasma volume (PV)) were assessed. Monitoring included physiological responses at rest (nocturnal oxygen saturation (SpO2) and heart rate, Hooper and Spiegel questionnaires, hydration status) and during exercise (incl. power, SpO2 through 45 min cycling at fixed heart rate). Both Hbmass (3.2% ± 3.1% for HYPOXIA, 3.7% ± 2.9% for COMBINED, p < 0.001) and PV (p = 0.003) increased during the camp, without interaction between groups (p ≥ 0.266). Exercise SpO2 decreased between the end of the second and the third week (p = 0.034, d = 0.583) in the COMBINED group. No difference between groups was detected for the other physiological or perceptual parameters. Adding heat training during the third week of an altitude training camp did not affect the increase in Hbmass or monitoring variables at rest. However, it did not confer any additional PV expansion and was associated with a reduced exercise SpO2
Vaccination against H5 HP avian influenza virus leads to persistent immune response in wild king penguins
No full textInternational audienceSince 2021, the panzootic nature of high pathogenicity avian influenza (HPAI) represents an increasing threat to wild vertebrate populations. In this context, recent vaccines developed for poultry could provide tools for the conservation of wild endangered birds populations. The king penguin ( Aptenodytes patagonicus ), a long-lived seabird breeding in dense colonies with an extended chick-rearing period, has been identified as a possible surrogate species for a vaccination trial in a sub-Antarctic natural setting. Here we investigate the immune response of king penguin chicks to a self-amplifying mRNA vaccine against a H5 HPAI clade 2.3.4.4b protein. The cohort entails thirty vaccinated chicks (primo- and boost-injections), and 20 unvaccinated controls. Along 250 days of monitoring, the vaccinated chicks show a high and persistent immune response, granting a strong sero-neutralisation capacity against the virus, up to fledging. No adverse effects are observed. Screening for antibodies against unspecific avian influenza viruses suggests that no natural infection has occurred over the entire trial. The emergence of HPAI in the Southern Indian Ocean in October 2024 highlights the timeliness of such experimental tests. Our results thus show the vaccine could provide a potentially powerful tool for mitigation of avian flu outbreaks in the wild
Les vases-miniatures du sanctuaire de Lachaup, à La Bâtie Montsaléon (05). Approche archéologique et archéométrique d’un ensemble d’ustensiles à forte valeur symbolique
No full textInternational audienceEn 2021, une fouille préventive réalisée par l’Inrap au cœur des Hautes-Alpes, sur le territoire de la commune de La Bâtie Montsaléon, livre un important corpus céramique relatif aux niveaux de fréquentation et d’abandon d’un sanctuaire connu de longue date et occupé entre le Ier et le IVe siècle de notre ère.Aux côtés des ustensiles destinés à la préparation et au service des aliments, cet ensemble comporte une cinquantaine de vases miniatures, formes emblématiques des contextes sacrés, se déclinant sur ce site en une demi-douzaine de types différents. Tous les exemplaires analysés sont fabriqués en céramique commune, mais seulement une partie d’entre eux relève de productions bien identifiées, en particulier celles des ateliers de la moyenne vallée du Rhône. Une enquête pétrographique menée sur une sélection d’exemplaires moins bien caractérisés permet d’appréhender le profil technique de ces derniers et fournit quelques pistes de réflexion au sujet de leurs zones de production.Par ailleurs, des analyses chimiques ont pu être menées à l’occasion de la post-fouille sur l’un de ces vases miniatures découvert en position primaire sur l’un des sols du sanctuaire, avec dix autres petits vases. Les résultats obtenus nous dévoilent l’identité des contenus ayant marqué ces récipients et nous permettent d’aborder ainsi un aspect fondamental des pratiques rituelles auxquelles ces derniers participent.Lo scavo preventivo realizzato nel 2021 dall’Inrap nel cuore delle Alpi, sul territorio del comune de La Bâtie Montsaléon, ha fornito un insieme ceramico importante, relativo ai livelli di occupazione e di abbandono di un santuario conosciuto da vari decenni e occupato tra il I et il IV secolo dopo Cristo.Oltre alle suppellettili destinate alla preparazione e al servizio degli alimenti, questo insieme comporta una cinquantina di vasi miniatura, forma emblematica dei contesti sacri, qui illustrata da una mezza dozzina si tipi differenti. Tutti gli esemplari analizzati sono prodotti in ceramica comune ma solo una parte è attribuibile a delle produzioni note, in particolare quelli che provengono dalla media valle del Rodano. Un’indagine petrografica realizzata su alcuni esemplari prodotti con argille calcaree ha permesso di caratterizzarne con più precisione il profilo tecnico.Peraltro, una serie di analisi chimiche realizzate su uno dei vasi ritrovato in posizione primaria sul sito ne svela il contenuto e permette di trattare un aspetto fondamentale delle pratiche rituali alle quali questi vasi erano associati in età romana
New species of Endaeus Schoenherr, 1826 (Curculionidae: Curculioninae: Ochyromerini) associated with Annonaceae and Clusiaceae
No full textInternational audienceRepresentatives of the weevil tribe Ochyromerini (Coleoptera: Curculionidae: Curculioninae) have been increasingly reported as specialized pollinators of Annonaceae Juss., with some species in the genus Endaeus Schoenherr, 1826 engaging in brood-site pollination with their host. Recent investigations into the poorly documented life history of these pollinators have led to the discovery of new species in the genus Endaeus and provided details of their life histories. The following species are herein described: E. canangae Haran sp. nov. from Southeast Asia, associated with Cananga odorata (Lam.) Hook.f. and Thomson (Annonaceae); E. lenticulatus Haran sp. nov. from Central Africa, associated with Uvariodendron molundense (Diels) R.E.Fr. (Annonaceae); E. xylopiae Haran and Zelvelder sp. nov., E. jaculifer Haran and Zelvelder sp. nov. and E. convexiculus Haran and Zelvelder sp. nov. from Central Africa, associated with Xylopia aethiopica (Dunal) A.Rich. (Annonaceae) and E. staminicola Haran sp. nov. also from Central Africa, associated with Allanblackia floribunda Oliv. (Clusiaceae Lindl.). Pictures of habitus and terminalia of adults, molecular and morphological diagnostic tools along with life history data are provided for each species. These new associations are discussed in light of the general patterns of specialized brood-site pollination mutualism between plants and weevils
Critères éthiques et évaluation des politiques publiques : Liberté, égalité, efficacité ?
No full textDans un cadre welfariste strict, les objectifs poursuivis par une politique publique se concentrent sur un objectif d'efficacité. Le plus souvent, il s'agit de valoriser au mieux l'utilité des individus, avec la plus grande économie de moyens, tout en négligeant d'autres critères potentiellement désirables. Les approches dites non welfaristes, auxquelles Daniel Serra a apporté plusieurs contributions, ont permis de questionner plus largement les politiques publiques en introduisant de nouveaux arguments liés à la justice sociale : l'égalité, la liberté, le non-paternalisme. Dans cet article, nous proposons de montrer l'apport de ces approches alternatives à travers deux études de cas : celle du taux de remplissage des trains et celle de la gratuité dans les musées. Nous en tirons deux conclusions générales. Conformément à la démarche de l'économie normative, la priorité accordée à un critère éthique plutôt qu'à un autre conduit à suggérer des politiques publiques différentes. La mesure de politique qui satisfait un critère éthique donné diffère selon le contexte du cas étudié
Trajectoires des petites villes « délaissées » : une analyse comparative des dynamiques de redéveloppement, entre logiques institutionnelles et pratiques alternatives
No full textBecause of their vulnerable situation, of loss attractiveness, decaying centralities, and economic difficulties, declining small towns are still on the fringe of major political, economic, and entrepreneurial agendas, to the benefit of metropolitan areas (Taulelle, 2010). Lacking real urban engineering, many persist in implementing mainstream redevelopment policies, replicating on a smaller scale metropolitan and neoliberal policies (Edouard, 2014), based on competitiveness, attractiveness, and territorial marketing. These strategies seem ill-suited to small towns in decline, and even contribute to worsening their situation (Béal et al. 2019). However, this marginalization has allowed, in some, the emergence of a fertile ground for new forms of experimentation, initiatives (Euvé, 2022), and local mobilizations broking away from institutional strategies and urban entrepreneurship. These examples foreshadow the potential for doing things differently: thinking, living and building differently. Consequently, these left-behind small towns, who until recently were suffering from decline, seem to have transitioned into a new era, promoting the emergence of alternative practices (Béal; Rousseau, 2015). Thus, based on a comparative analysis of three small towns outside metropolitan areas - Lodève (Hérault), Loos-en-Gohelle (Pas-de-Calais), and Briançon (Hautes-Alpes) - this thesis aims to analyze to what extent do these alternative practices initiate post-decline redevelopment trajectories for neglected small towns ?Souvent fragilisées par des phénomènes de dévitalisation de leurs centralités, de perte d'attractivité et des difficultés en matière économique, commerciale et sociale, les petites villes en déclin ont longtemps été minorées, si ce n'est délaissées par les politiques publiques et la recherche scientifique au profit des métropoles (Taulelle, 2010). A l'écart des grandes préoccupations étatiques, politiques, économiques et entrepreneuriales, et dépourvues de grands schémas d'aménagements urbains, beaucoup persistent à mettre en œuvre des stratégies de réaménagement traditionnelles, reproduisant à plus petite échelle les politiques métropolitaines (Edouard, 2014) de types néolibérales, inadaptées aux contextes de ces petites villes (Béal et al., 2019). Certaines, à l'inverse, semblent avoir tiré profit de cette marginalisation. Cette situation de mise à l'écart durant de nombreuses années a facilité l'émergence d'un terreau fertile pour de nouvelles formes d'expérimentations, d'initiatives (Euvé, 2022) et de mobilisations locales, s'éloignant des stratégies institutionnelles et de l'entrepreneurialisme urbain. Ces exemples laissent alors entrevoir la potentialité d'un « autrement » : penser autrement, vivre autrement, construire autrement, habiter autrement ; qui constitue tout l'intérêt de ce projet de recherche. Par conséquent, certaines de ces petites villes délaissées qui hier subissaient le déclin, semblent pour l'heure avoir basculé vers une nouvelle ère, favorisant l'émergence de nouvelles pratiques « alternatives » (Béal ; Rousseau, 2015). Ainsi, en s'appuyant sur une analyse comparative de trois petites villes hors champs métropolitain - Lodève (Hérault), Loos-en-Gohelle (Pas-de-Calais) et Briançon (Hautes-Alpes) - cette thèse entend analyser dans quelles mesures ces pratiques alternatives initient-elles des trajectoires de redéveloppement post-déclin des petites villes délaissées
Participation à la soirée d'hommage consacrée au poète René Depestre organisée à la Maison de la Poésie de Paris
No full textContribution à la soirée d'hommage au poète René Depestre, Maison de la Poésie (Paris)Contribution (lecture, table-ronde) à la soirée d'hommage aux 100 ans du poète René Depestre organisée à la Maison de la Poésie de Paris par le poète James Noë
Design and Optimization of Solar-Powered Embedded Systems with Uppaal Stratego
No full textInternational audienceEnergy intermittency in solar-powered embedded systems threatens Quality of Service (QoS) and system autonomy. In this study, we address the design of these systems with a formal co-design approach that provides verifiable guarantees, a critical advantage over traditional heuristic or predictive methods that often fail under unpredictable conditions. We use timed automatabased modeling within Uppaal Stratego to minimize grid reliance and battery capacity in a typical system, under QoS guarantees. Our methodology demonstrates that synthesized control strategies can reduce grid reliance by 58-72%, while an optimized task scheduling heuristic can decrease required battery capacity by up to 13% compared to the baseline. Our approach provides a formal basis for comparing these techniques to inform system design