HAL Portal UPF (Université de la Polynésie française)
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“To Be, or Not to Be”: Critical Assessment of the Use of α-Acoustic Diversity Indices to Evaluate the Richness and Abundance of Coastal Marine Fish Sounds
No full textInternational audiencePassive acoustic monitoring can be used to assess the presence of vocal species. Automatic estimation of such information is critical for allowing diversity monitoring over long time spans. Among the existing tools, αacoustic indices were originally designed to assess the richness/complexity of terrestrial soundscapes. However, their use in marine environments is impacted by fundamental differences between terrestrial and marine soundscapes. The aim of this study was to determine how they vary depending on the abundance and sound type richness of fish sounds. Fourteen indices used in terrestrial environments were tested. The indices were calculated for files from three sources: a controlled environment (playback of artificial tracks in a pool), in situ playbacks (playback of natural soundscapes), and a natural environment (only natural sounds). The controlled experiment showed that some indices were correlated with the sound abundance but not with the sound type richness, implying that they are not capable of distinguishing the different types of fish sounds. In the in situ playbacks, the indices were not able to capture differences, both in terms of the sound abundance and sound type diversity. In the natural environment, there was no correlation between most of the indices and the abundance of sounds. They were impacted by mass phenomena of biological sounds (e.g., the Pomacentridae sounds in shallow reefs) that cannot inform on fish acoustic diversity. Indices are appropriate when soundscapes are divided into bands. In contrast to terrestrial environments, frequency bands in coastal marine soundscapes do not provide ecologically relevant information on diversity. Overall, indices do not appear to be suitable for inferring marine fish sound diversity
Genetic evidence for plastic reproductive philopatry and matrotrophy in blacktip reef sharks (Carcharhinus melanopterus) of the Moorea Island (French Polynesia)
No full textInternational audienceThe exploitation of sharks and the degradation of their habitats elevate the urgency to understand the factors that influence offspring survival and ultimately shark reproductive success. We monitored and sampled blacktip reef sharks ( Carcharhinus melanopterus ) in nursery habitats of Moorea Island (French Polynesia), to improve knowledge on shark reproductive behavior and biology. We sampled fin clips and morphometrics from 230 young-of-the-year sharks and used microsatellite DNA markers to process parentage analysis to study the reproductive philopatric behavior in female sharks and the matrotrophy within litters. These traits are driving the success of the local replenishment influencing selection through birth site and maternal reserves transmitted to pups. Parentage analysis revealed that some female sharks changed their parturition areas (inter-seasonally) while other female sharks came back to the same site for parturition, providing evidence for a plastic philopatric behavior. Morphometrics showed that there was no significant relationship between body condition indices and nursery locations. However, similarities and differences in body condition were observed between individuals sharing the same mother, indicating that resource allocation within some shark litters might be unbalanced. Our findings further our understanding of the reproductive biology and behavior that shape shark populations with the aim to introduce these parameters into future conservation strategies
Pearl shape classification using deep convolutional neural networks from Tahitian pearl rotation in Pinctada margaritifera
No full textInternational audienceTahitian pearls, artificially cultivated from the black-lipped pearl oyster Pinctada margaritifera, are renowned for their unique color and large size, making the pearl industry vital for the French Polynesian economy. Understanding the mechanisms of pearl formation is essential for enabling quality and sustainable production. In this paper, we explore the process of pearl formation by studying pearl rotation. Here we show, using a deep convolutional neural network, a direct link between the rotation of the pearl during its formation in the oyster and its final shape. We propose a new method for non-invasive pearl monitoring and a model for predicting the final shape of the pearl from rotation data with 81.9% accuracy. These novel resources provide a fresh perspective to study and enhance our comprehension of the overall mechanism of pearl formation, with potential long-term applications for improving pearl production and quality control in the industry
Table ronde autour des pratiques de science ouverte de la communauté scientifique
No full textCommunication oraleNational audienceL’UPHF relève le défi de la science ouverte ! Suite à la création de son portail HAL en 2019, et dans la lignée des deux Plans nationaux pour la Science ouverte, l’UPHF a voté en 2021 son Plan Science Ouverte et a mis en place une série de mesures favorables à sa promotion, au niveau local comme au niveau de l’alliance européenne. Cette table ronde s'est tenue pendant une journée d’étude consacrée à la science ouverte à l’UPHF et réunissait plusieurs chercheurs de l’université afin de discuter de leurs pratiques de la science ouverte ainsi que des défis que cette dernière doit relever pour l’avenir
Is creeping abandonment of human cancer defences evolutionarily favoured?
No full textInternational audienceAmong observed animal species, humans exhibit a remarkably elevated lifetime cancer risk (over 38%), in stark contrast to less than 10% seen in other observed species (excluding those affected by environmental pollution). Peto's paradox suggests that these observations defy explanation through mathematical models treating cancer genesis as a stochastic process, with risks resulting from lifespan and body mass. For instance, whales, despite longer lifespans and roughly 30 times the size of humans, maintain consistent cancer risk throughout life, differing from the pronounced increase after female reproductive age observed in humans. It is well-documented in the literature that species-specific tumor suppression mechanisms allow for large lifespan and body mass. Examination of data from chimpanzees, a closely related species, suggests—without definitive evidence—a major difference between chimpanzee and human cancer risk. This leads to the conjecture that vulnerability of cancer defence mechanisms in humans might have emerged due to the unique evolutionary trajectory of the genus _Homo_. Given that this vulnerability emerges after reproductive years, a prevailing hypothesis attributes it to antagonistic pleiotropy. However, considering _Homo's_ historical existence in small tribes throughout much of evolution, we suggest that natural selection may have also operated at the tribal level. Consequently, our hypothesis, "Is creeping abandonment of human cancer defences evolutionarily favored?" arises from two alternative speculative scenarios. One proposition rests on the notion that diminishing tumor suppression activities could confer a calorie-saving advantage, particularly beneficial for tribes with limited food resources. The other proposition suggests that creeping abandonment of cancer defences might promote genetic diversity
Le climat universitaire à l’INSPE de Martinique. Rapport préliminaire d’enquête (edition 2023)
No full textCe rapport présente les premiers résultats de l'enquête "Climat universitaire à l’INSPE de Martinique", réalisée entre novembre et décembre 2023 par les étudiants de la première année du Master MEEF - mention Encadrement éducatif (Université des Antilles). Les répondants (N=102) font état d’une insatisfaction latente plutôt que d’un franc mécontentement et soulignent les faiblesses structurelles qui exercent un impact négatif sur leur formation (notamment des bâtiments en mauvais états et des ressources d'apprentissage inadaptées) tout comme les éléments positifs (la débrouillardise de certains enseignants, la qualité de l'offre de formation, l'esprit d'entraide entre les étudiants)
Antimicrobial Properties of Compounds Isolated from Syzygium malaccense (L.) Merr. and L.M. Perry and Medicinal Plants Used in French Polynesia
No full textA preliminary ethnopharmacological survey, achieved in French Polynesia, led to the collection of the most cited plants among 63 species used to treat “infectious” diseases, with a description of their medicinal uses. Bibliographical investigations and antimicrobial screening permitted the selection of the botanical species Syzygium malaccense (Myrtaceae) for phytochemical analysis. Leaves of Syzygium malaccense were usually used in mixture with rhizomes of Curcuma longa to treat infectious diseases such as cystitis. The methanolic plant extracts were tested in vitro with an agar microdilution method on 33 bacteria strains and 1 yeast to obtain their Minimal Inhibitory Concentration (MIC), and cytotoxicity against HepG2 cells were evaluated. Antimicrobial synergistic effects of methanolic plant extracts from leaves of Syzygium malaccense and rhizomes from Curcuma longa were also evaluated. The bio-guided isolation of leaf extract from Syzygium malaccense led to the identification of seven alkyl-salicylic acids (anacardic acids or ginkgolic acids C15:0, C15:1, C17:0, C17:1, C17:2, C17:3 and C19:1) described for the first time in this species. All compounds were tested against Staphylococcus aureus (18.75 < MIC < 75.0 µg/mL), Streptococcus pyogenes (2.34 < MIC < 18.75 µg/mL) and Pseudomonas aeruginosa (MIC = 150 µg/mL), and their structure–activity relationships were discussed. The methanolic extract and salicylic derivatives from S. malaccense showed an interesting antimicrobial activity against Gram+ bacteria, without toxicity on hepG2 cells at 400 μg/mL. Moreover, these antibacterial compounds have already been studied for their anti-inflammatory activity, which supports the therapeutic interest of S. malaccense against infectious diseases
Vivre avec les morts. Occupation du territoire et aménagements des espaces dans l'Antiquité: Carte blanche à Antiquité-Avenir
No full textInternational audienceLes sociétés antiques pensèrent la cohabitation entre les vivants et les morts. Les morts avaient leur ville : c’est le sens de « nécropole ». Il était interdit d’ensevelir les morts dans la Ville ; les nécropoles romaines étaient donc hors les murs. À Délos, dont les terres étaient consacrées à Apollon, la nécropole se trouvait sur l'île voisine de Rhénée. Pourtant, cette règle ne semble pas universelle. Dans la ville d'Ur, au pays de Sumer, les sépultures diffèrent en fonction de l'époque et du statut des morts, mais toutes ont été retrouvées intra-muros. Les sources archéologiques et épigraphiques permettent de reconstitué, en partie, les rites funéraires attachés à ces sépultures