HAL Collection UNC (Univ. de la Nouvelle Calédonie)
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Growth Patterns of Reef-Building Porites Species in the Remote Clipperton Atoll Reef
No full textInternational audienceRemote reefs offer insights into natural coral dynamics, influenced by regional environmental factors and climate change fluctuations. Clipperton Atoll is the eastern tropical Pacific’s most isolated reef, where coral reef growth and life strategies have been poorly studied so far. Recognizing the coral species’ growth response might help understand ecological dynamics and the impacts of anthropogenic stressors on coastal reefs. The present study evaluates annual coral growth parameters of the most abundant coral reef-building species, Porites australiensis, Porites arnaudi, Porites lutea, and Porites lobata. The results showed that during 2015–2019, corals exhibited the lowest annual linear extension (0.65 ± 0.29 cm yr−1), skeletal density (1.14 ± 0.32 g cm−3), and calcification rates (0.78 ± 0.44 g cm−2 yr−1) for the genera along the Pacific. Differences in growth patterns among species were observed, with Porites lutea and Porites lobata showing a higher radial extension, developing massive-hemispherical morphologies, and acting as structural stabilizers; meanwhile, P. arnaudi and P. australiensis exhibited more skeletal compaction but also with a high plasticity on their morphologies, contributing to benthic heterogeneity. These differences are particularly important as each species fulfills different ecological functions within the reef, contributing to the ecosystem balance and enhancing the relevance of the massive species in the physical structure of remote reef systems, such as Clipperton Atoll
Exploring potential fish sound producers in Polynesian lower mesophotic coral reefs
No full textInternational audienceMesophotic coral reefs host unique fish assemblages and highly diverse biological sounds. However, many of the sources of these sounds remain unknown. The objectives of this study are to identify, based on the literature, the soniferous fish species present in the deep part of mesophotic coral ecosystems (MCEs) in French Polynesia; and to infer the sounds produced by the species present to link them with previously recorded sounds. A total of 39 fish families through to produce sounds were found to be possibly present at 120 m depth. This list includes well-known families such as Serranidae and Ophidiidae. The most abundant sound recorded in Polynesian mesophotic reefs exhibits similarities to sounds produced by Mediterranean Scorpaena species (Scorpaenidae), a genus also present in Polynesian MCEs. This study provides initial insights into which soniferous fish taxa are present in Polynesian MCE
"Performer le plurilinguisme et l’interculturel", in M. Bento (dir.) « L’enseignement du FLE en mutation : défis et perspectives – Éclairages d’Asie et d’ailleurs »
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The Fast-Greedy algorithm reveals hourly fluctuations and associated risks of shark communities in a South Pacific city
No full textUnprovoked shark bites are increasing globally. Regional hotspots like Nouméa show rising incidents involving bull sharks (Carcharhinus leucas) and tiger sharks (Galeocerdo cuvier), leading to the culling of these protected species. Identifying high-risk areas and times is key to balancing human safety and shark conservation. Here, we collected five years of acoustic telemetry data for both shark species in the lagoon of Nouméa. The data were categorized by species, divided into 24 hourly subsets, and modeled as bipartite graphs. The Fast-Greedy algorithm was applied to identify distinct communities of sharks and stations. Normalized mutual information was used to cluster communities and detect spatiotemporal patterns. The study revealed up to 9 hourly communities for bull sharks and 21 for tiger sharks, each grouping into 3 clusters. Several high-risk areas and times were identified. Bull sharks formed schools, and a cluster was observed in the harbor between 6:00 and 13:00, increasing bite risk on nearby beaches in the morning. Tiger sharks were more solitary and were present day and night at most stations except those in relatively turbid areas. Both species showed fission–fusion dynamics, with communities merging at dusk, indicating increased movement and a higher risk during this low-light period. A key innovation of our modeling framework was its ability to handle temporal variability in community detection algorithms applied to bipartite networks. The model identified key overlap periods of shark–human activity, highlighting the need for real-time monitoring, safety measures, and public awareness to reduce bite risk and promote coexistence
Creating Multimedia Resources for Kanak Languages Using the C-LARA Platform: Case Studies in Iaai and Drehu
No full textInternational audienceWe describe an ongoing project where a diverse team, including linguists, ethnomusicologists, applied linguists, language teachers, and computer scientists, is developing multimedia resources for two Kanak languages of New Caledonia—Iaai and Drehu—using the ChatGPT-based Learning And Reading Assistant (C-LARA) platform. C-LARA (https://www.c-lara.org/; (Bédi et al., 2023, 2024)) is an open source platform powered by artificial intelligence (AI) enabling non-expert users to rapidly create illustrated multimodal content for language learners. We present initial proof-of-concept resources already completed and outline plans for further work.For Drehu, the language of the island of Lifou and one of the languages of Tiga, and the Kanak language with the largest community of speakers (approx. 16,000), we developed an interactive alphabet book and a C-LARA edition of Leu me Jö (The (North) Wind and the Sun), a Drehu version of Aesop’s fable. These resources feature Drehu words with accompanying AI-generated images and audio pronunciations recorded by native speakers. The platform provides phonetic annotations using pronunciation respellings based on French orthography (franétique transcriptions, derived from français + phonétique), aiding learners in correct pronunciation and mitigating cross-language orthographic conflicts (see Figure 1). The grapheme-phoneme correspondences were based on the conventions of the Académie des Langues Kanak’s Proposition d’Écriture for Drehu (Sam, 2009) as well as our own research (Anonymous).In Iaai, spoken by around 3,700 speakers mainly on the island of Ouvéa, we created a multimedia version of Wanakat Kaori, a bilingual Iaai-French tale (see Figure 2) adapted from traditional oral literature (Hombouy et al., 2005), as well as several children’s songs, lullabies, and contemporary music pieces. For Wanakat Kaori, we used illustrations from the original storybook, while AI-generated images were created for the other texts. All resources include audio recordings by native speakers. We collaborated closely with the Académie des Langues Kanak (ALK) to ensure adherence to Iaai writing norms (2020) and cultural appropriateness.One challenge was addressing limitations in using AI to create images depicting specific cultural contexts, which we mitigated through prompt engineering and community feedback. Here, the involvement of the ALK and community members was pivotal in refining the resources, ensuring they were culturally relevant and accurately represented the languages. Another challenge was adapting C-LARA to work with Indigenous languages unfamiliar to the AI. Since then, we have enhanced the platform to better handle these challenges by improving the platform’s ability to support manual annotation and glossing in unfamiliar languages and refining the AI-based image generation techniques.Our work demonstrates the potential of AI in supporting linguistic documentation and education for endangered languages. By combining advanced technology with community collaboration, we contribute to the preservation and promotion of Kanak languages, showing how AI tools can be adapted to create culturally relevant multimedia resources for languages with limited digital presence. All materials described are freely accessible online; the final version of this abstract will include links. We are currently developing substantially larger resources for Kanak languages, some of which we expect to have made available by the time of the conference.ReferencesAcadémie des Langues Kanak (2020). Propositions d’écriture du iaai, langue parlée a Ouvéa, Nouvelle-Calédonie. Hna setr hwen iaai ae thep ûnyi. Académie des Langues Kanak.Bédi, B., ChatGPT-4 C-LARA-Instance, Chiera, B., Chua, C., Cucchiarini, C., Dotte, A.-L., Geneix-Rabault, Stéphanie Maizonniaux, C., M˘arginean, C., Ní Chiaráin, N., Parry-Mills, L., Raheb, C., Rayner, M., Simonsen, A., Viorica, Wacalie, F., Lucret,ia, M., Welby, P., Xiang, Z., and Zviel-Girshin, R. (2024). ChatGPT-Based Learning And Reading Assistant (C-LARA): Second report. Technical report. https://www.researchgate.net/publication/379119435_ChatGPT-Based_Learning_And_Reading_Assistant_C-LARA_Second_Report.Bédi, B., ChatGPT-4 C-LARA-Instance, Chiera, B., Chua, C., Cucchiarini, C., Ní Chiaráin, N., Rayner, M., Simonsen, A., and Zviel-Girshin, R. (2023). ChatGPT-Based Learning And Reading Assistant: Initial report. Technical report. https://www.researchgate.net/publication/372526096_ChatGPT-Based_Learning_And_Reading_Assistant_Initial_Report.Hombouy, M., Wea, G., and Goulon, I. (2005). Wanakat kaori — L’enfant kaori. ADCK-CCT-Grain de sable, Nouméa.Sam, L. D. (2009). Aqane cinyihanyi
Quand l’IA se trompe, on apprend : une approche interculturelle et critique de l’IA en télécollaboration
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Dessine-moi la mer
No full textLe dessin peut être utilisé pour identifier et comprendre les savoirs écologiques des enfants, mais aussi leurs représentations et émotions, et comme support de dialogue entre sciences et sociétés
Gambierdiscus polynesiensis from New Caledonia (South West Pacific Ocean): Morpho-molecular characterization, toxin profile and response to light intensity
No full textInternational audienceGambierdiscus is known to produce neurotoxins associated with ciguatera poisoning (CP). In New Caledonia (NC), South West Pacific Ocean, there is currently a significant knowledge gap regarding CP and the microalgae linked to this foodborne illness. This study describes a new strain of Gambierdiscus polynesiensis, 19PV93, isolated from the west coast of NC. The strain was isolated and cultured for morpho-molecular characterization to determine its phylogenetic position. Toxic activity was assessed using a cell-based assay with neuroblastoma cells (CBA-N2a), and the toxin profile was characterized using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) to evaluate potential risks to human health. Regarding the toxin profile, G. polynesiensis was characterized by the presence of gambierone, 44-methylgambierone (44-MeG), and an atypical ciguatoxin profile consisting solely of ciguatoxin-4A (CTX4A) and -4B (CTX4B). This finding confirms intraspecific variations in toxin profiles between strains from different geographic origins. In culture, G. polynesiensis demonstrated a preference for relatively low irradiances (50 to 100 µmol photons m⁻² s⁻¹) compared to the higher light intensities often encountered in their natural environment. The impact of light on toxin concentrations was found to be inversely related to light intensity, with higher quotas observed at lower light levels. Gambierdiscus employed non-photochemical quenching as a photoprotective strategy to safeguard PSII from excessive light, particularly during both short-term and long-term exposure. However, this dissipation strategy alone appears insufficient, as photoinhibition was consistently observed, and the electron transfer rate and yield along the electron transfer chain rapidly declined with increasing light intensity
Les motivations des e-shoppers du luxe : du « need for status » au « need for cognition »
No full textInternational audienceThis article aims to understand the motivations of luxury e-shoppers, to see if they differ from the classic motivations for buying luxury products. Three qualitative studies are conducted: a netnography, interviews with luxury and digital experts, and interviews with luxury consumers. The results show that new motivations are emerging for online luxury consumers, who are more inclined towards "need for cognition" than "need for status".Cet article vise à appréhender les motivations des e-shoppers du luxe afin de voir si elles diffèrent des motivations classiques de l’achat de produit de luxe. Trois études qualitatives sont menées : une netnographie, des entretiens d’experts du luxe et du digital, et des entretiens de consommateurs de luxe. Les résultats montrent que de nouvelles motivations émergent chez le consommateur de luxe en ligne plus enclin au « need for cognition » qu’au « need for status »