HAL Portal UPF (Université de la Polynésie française)
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La langue tahitienne : parcours d’apprenants adultes
No full textNotre environnement nous façonne, de même que les langues que nous entendons et les représentations que nous en avons. Fruit d’un travail de recherche de quatre mois, mené parallèlement à mes engagements professionnels, ce mémoire vise à déconstruire certains clichés concernant l’apprentissage du tahitien, en particulier à l’âge adulte, afin de rendre le reo tahiti accessible à tous. À travers les parcours d’apprenants adultes ayant accepté de participer à des entretiens semi directifs, nous analysons les stratégies d’apprentissage efficaces, dans un contexte où les technologies évoluent constamment. Nous prions le lecteur de bien vouloir excuser les quelques coquilles encore présentes dans cette version révisée ; il semblerait que quatre mois et un emploi à temps plein ne suffisent pas toujours à dompter la langue française, même pour un mémoire sur le tahitien ! La réflexion présentée ici est encore jeune, mais j’espère que ce travail pourra être utile et stimulant pour les esprits curieux, et qu’un jour un travail plus abouti pourra voir le jour
Highlighting the resilience potential of marine protected areas in the face of coral bleaching with passive acoustic monitoring
No full textInternational audienceMarine Protected Areas (MPAs) can increase the resilience of reef communities to disturbances, playing a role in sheltering biodiversity from climate-related impacts. To determine if the protection status allows for better resilience after coral bleaching events, we recorded soundscapes of eight reefs of Moorea Island (French Polynesia). We compared the biophony of MPAs to the one of adjacent non-protected zones recorded in 2015, before two bleaching events (2016 and 2019), to the one in 2021. Then, the biophony from 2021 was compared within and outside MPAs. We hypothesize that differences in the biophony between these periods vary within and outside MPAs. The main result is an increase in the nocturnal high frequency (2–22 kHz) mass phenomena of benthic invertebrates, observed at sites with higher coral cover post-bleaching compared to pre-bleaching: nocturnal power spectral density (PSD) and peak frequency of invertebrate sounds varied between 2015 and 2021. For fish sounds, no daytime difference was observed, while nocturnal PSD was higher in 2021. These observations reflect distinct bleaching histories. High-frequency PSD measurements and the associated frequency values demonstrated strong correlation with temporal changes in coral cover. We suggest including it in long-term reef monitoring due to its complementary nature with respect to classical methods
Entre soi et ailleurs : femmes francophones en Océanie et en Orient dans les premières décennies du XXe siècle: Isabelle Eberhardt, Renée Hamon, Titaÿna
No full textInternational audienceAt the beginning of the twentieth century, as the French colonial empire reached its height, certain Francophone women embraced travel as a space for self-reinvention and for the displacement of norms. Isabelle Eberhardt, Renée Hamon, and Titaÿna belong to a paradoxical modernity: caught within the patriarchal and colonial logics of the Third Republic, they nevertheless transgress their domestic confinement by writing from elsewhere. Their itineraries, in Oceania or the Orient, cannot be reduced to a mere exotic escape: they give rise to a poetics of instability and to a subjectivity constantly torn between rootedness and displacement. By engaging in travel writing, a genre historically associated with the masculine and conquering explorer, these authors subvert its codes by adopting a lateral, sometimes ironic, often ambiguous position. Their texts are situated within the contact zones described by Mary Louise Pratt: spaces of unequal exchange, marked by the friction between colonizing and colonized cultures. The subjectivity they construct there is not fixed but fluid, shaped by otherness, misalignment, and the experience of uprooting. Thus, in Isabelle Eberhardt’s work, immersion in the Algerian desert expresses an inner asceticism and a mystical quest for de-identification. In Renée Hamon’s writing, travel in Polynesia becomes a critical and ethical posture of listening, attentive to Indigenous voices and to the silences imposed by the colonial regime. In Titaÿna’s case, elsewhere takes the form of a flamboyant and unstable media stage, where the spectacular affirmation of self is coupled with a deep inner dissonance. These feminine writings, situated between observation and involvement, intimacy and politics, do not constitute pure counter-discourses to the colonial enterprise. Rather, they reveal its margins, its cracks, and its contradictions, outlining an imaginary of displacement that escapes both heroic linearity and ethnographic transparency. Their narratives propose another way of inhabiting elsewhere: the Orient and Oceania then function as symbolic matrices of subjectivation, the one, saturated with history and religious tensions, becoming a place of immersion and solitude; the other, marked by the illusions and disillusions of colonial utopia, becoming a critical space of questioning. At the crossroads of literary modernity and colonial history, the texts of Isabelle Eberhardt, Renée Hamon, and Titaÿna reveal feminine subjectivities in transit, in constant becoming, fragile yet productive. Their writing, fragmented and unstable, inscribes a poetics of fracture and misalignment, opening a critical space where the relations between identity, otherness, and power are reconfigured. These narratives thus invite us to read women’s travel not as conquest nor as simple emancipation, but as a testing of the self in contact with the other.Au début du XXe siècle, alors que l’Empire colonial français connaît son apogée, certaines femmes francophones investissent le voyage comme espace de réinvention de soi et de déplacement des normes. Isabelle Eberhardt, Renée Hamon et Titaÿna s’inscrivent dans une modernité paradoxale : prises dans les logiques patriarcales et coloniales de la Troisième République, elles transgressent néanmoins leur assignation au foyer en écrivant depuis l’ailleurs. Leurs itinéraires, océaniens ou orientaux, ne se réduisent pas à une échappée exotique : ils donnent lieu à une poétique de l’instabilité et à une subjectivité toujours en tension entre ancrage et décentrement. En investissant le récit de voyage, genre historiquement associé à l’explorateur masculin et conquérant, ces autrices déjouent les codes en adoptant une position latérale, parfois ironique, souvent ambiguë. Leurs textes se situent dans les contact zones décrites par Mary Louise Pratt : lieux d’échange inégal, traversés par la friction entre cultures colonisatrices et colonisées. La subjectivité qu’elles y déploient n’est pas fixe mais mouvante, travaillée par l’altérité, le désajustement et l’expérience du déracinement. Ainsi, chez Isabelle Eberhardt, l’immersion dans le désert algérien traduit une ascèse intérieure et une quête mystique de désidentification. Chez Renée Hamon, le voyage en Polynésie devient posture critique et éthique d’écoute, sensible aux voix autochtones et aux silences imposés par le régime colonial. Chez Titaÿna enfin, l’ailleurs prend la forme d’un théâtre médiatique, flamboyant et instable, où l’affirmation spectaculaire de soi se double d’une profonde dissonance intérieure. Ces écritures féminines, situées entre observation et implication, intime et politique, ne constituent pas de purs contre-discours à l’entreprise coloniale. Elles en révèlent plutôt les marges, les fissures et les contradictions, dessinant un imaginaire du déplacement qui échappe à la linéarité héroïque ou à la transparence ethnographique. Leurs récits proposent un autre mode d’habiter l’ailleurs, Orient et Océanie fonctionnent alors comme matrices symboliques de subjectivation : l’un, saturé d’histoire et de tensions religieuses, se fait lieu d’immersion et de solitude ; l’autre, marqué par les illusions et désillusions de l’utopie coloniale, devient espace critique d’interrogation. Au croisement de la modernité littéraire et de l’histoire coloniale, les textes d’Isabelle Eberhardt, Renée Hamon et Titaÿna révèlent des subjectivités féminines en transit, en devenir constant, fragiles mais productives. Leur écriture, fragmentée et instable, inscrit une poétique de la faille et du désajustement, ouvrant un espace critique où se recomposent les rapports entre identité, altérité et pouvoir. Ces récits invitent ainsi à lire le voyage féminin non comme conquête ni comme simple émancipation, mais comme mise à l’épreuve du moi au contact de l’autre
Perception and discrimination of chemical and visual stimuli in Antillean manatees under human care
No full textInternational audienceAbstract Chemoreception represents a primitive sense in many mammals. Although evidence of functional olfaction is described in some cetaceans and pinniped species, findings considering Sirenians are scarce. We investigated the reactions of three Antillean manatees under human care to chemical stimuli: two food-related stimuli, one social-related stimulus and frozen water (control). A fish aggregation around the diffuser on manatees’ behavior was also monitored to test its influence on manatees’ behavior. Behaviors related to interest, social groupings and acoustic activity were recorded. The results showed that the density of fish around the diffuser influenced the manatees’ visual orientation and vocal rate. The manatees were also more present in the test area and decreased the duration and peak frequency of their calls after the diffusion of the feces odor compared to the control condition. Finally, they spent less time close to the device during fennel (plant) diffusion compared to the control condition. This work provides new evidence to the functionality of chemical perception in manatees. It also discusses the implication of other sensory cues and learning mechanisms in their foraging behaviors. We suggest that investigation of manatees’ reactions to environmental changes should include behavioral and acoustical measure
The transnational dimension of knowledge production and the development of safety infrastructures at the CEP in the era of atmospheric testing (1962-1975)
No full textInternational audienceWhen France established the Centre d’expérimentation du Pacifique (CEP) in French Polynesia in 1963, its scientists and technicians lacked knowledge on how to build firing ranges in island environments and establish a suitable security system. To fill these gaps, American and British scientific knowledge was sought in various ways (espionage, informal circulation of actors and documents) and actively mobilized. Although Anglo-American tests were considered counter-models to be avoided, France paradoxically adopted a mimetic stance in the design of its technical systems and security protocol, leading to cooperation with the Americans and the British. It also referred to international organizations (United Nations, International Atomic Energy Agency, International Commission on Radiological Protection) to develop its own security standards to protect itself from international disputes. This “imperial scheme” highlights the non-exclusively national character of the French nuclear testing program. From 1966 onwards, the testing campaigns led to a dispersion of radioactive fallout, which affected not only local populations but also diplomatic relations with several Pacific states (Australia, New Zealand, Fiji, Peru, Chile, Ecuador, among others). This situation also generated tensions between the French Commissariat à l’énergie atomique (CEA) and the Quai d’Orsay, whose technical priorities, on the one hand, and diplomatic priorities, on the other, diverged significantly. To respond to growing criticism, Paris once again mobilized its scientific and diplomatic influence by creating the global fallout monitoring network and sending technicians and scientists abroad. In 1974-1975, the move to underground testing renewed the transnational circulation of knowledge, and recourse to American expertise once again became a necessity
Evidence of vertical stratification in marine environments: insights from passive acoustic monitoring in French Polynesia
No full textInternational audienceThe stratification of species distribution in marine environments is well-documented, reflecting the influence of depth-related factors such as light availability, temperature, pressure, and habitat structure on the organization of marine communities. This study aimed to determine whether this stratification can also be highlighted using Passive Acoustic Monitoring (PAM), a technique proven effective in the study of various marine habitats. Sounds were recorded at 300 m in July 2022 off Moorea Island (French Polynesia) using a SNAP acoustic recorder. These data were compared to both those collected at shallower depths at Moorea Island (20, 60, and 120 m) and to data from other Polynesian islands obtained during a previous, non-concurrent study. Fish sounds in the recordings were manually identified. Richness and abundance of sounds from 20 m to 300 m depth were compared to assess whether fish communities in the altiphotic reef, upper mesophotic reef, lower mesophotic reef, and rariphotic zone could be distinguished based on the sounds they produce. Comparisons between zones over a 24-h period revealed for the first time the existence of acoustic stratification, with a fourfold decrease in species richness, from the altiphotic reef to the rariphotic zone, along with a general decline in sound abundance. However, this general pattern was not uniform in terms of abundance throughout the day, as sound abundance increased with depth at dusk from 950 sounds per hour at 20 m to 3600 at 300 m. It further confirms that diel activity patterns were also evident in light-deprived zones. This first exploration of vertical acoustic stratification based on fish sounds highlights the undeniable contribution of PAM to studies on the ecology of deep-sea communities
Le pouvoir normatif des institutions de la Polynésie française. A propos de l’avis de l’assemblée générale du Conseil d’État du 27 mars 2025, n° 409296 sur l’étendue du pouvoir réglementaire de l’assemblée la Polynésie française et du conseil des ministres dans le cadre de la mise en œuvre d’une loi du pays
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Asymmetry of the Relative Entropy in the Regularization of Empirical Risk Minimization
No full textInternational audienceThe effect of relative entropy asymmetry is analyzed in the context of empirical risk minimization (ERM) with relative entropy regularization (ERM-RER). Two regularizations are considered: (a) the relative entropy of the measure to be optimized with respect to a reference measure (Type-I ERM- RER); and (b) the relative entropy of the reference measure with respect to the measure to be optimized (Type-II ERM- RER). The main result is the characterization of the solution to the Type-II ERM-RER problem and its key properties. By comparing the well-understood Type-I ERM-RER with Type-II ERM-RER, the effects of entropy asymmetry are highlighted. The analysis shows that in both cases, regularization by relative entropy forces the support of the solution to collapse into the support of the reference measure, introducing a strong inductive bias that negates the evidence provided by the training data. Finally, it is shown that Type-II regularization is equivalent to Type-I regularization with an appropriate transformation of the empirical risk function
Variations de l’Espérance dues aux Changements de la Mesure de Probabilité
No full textIn this research report, closed-form expressions for the variation of the expectation of a given function due to changes in the probability measure (probability distribution drifts) are presented. These expressions unveil interesting connections with Gibbs probability measures, information projections, Pythagorean identities for relative entropy, mutual information, and lautum information.Dans ce rapport de recherche, nous présentons des expressions en forme fermée pour la variation de l’espérance d’une fonction donnée due à des changements de mesure de probabilité. Ces expressions révèlent des liens intéressants avec les mesures de probabilité de Gibbs, les projections informationnelles, les identités pythagoriciennes pour l’entropie relative, l’information mutuelle et l’information lautum
Au-delà du récit national, écrire une histoire internationale et transnationale des essais nucléaires en Polynésie française
No full textInternational audience46 essais aériens sont effectués entre 1966 et 1974, et 147 essais souterrains entre 1975 et 1996. La dimension globale et transnationale est à constater : les essais français s’affirment comme un élément structurant de la vie régionale au moment où s’engage la décolonisation de l’Océanie. Pour réaliser des essais, les responsables du Centre d’expérimentation du Pacifique (CEP) n’ont d’autres choix que de s’en remettre au savoir, à l’expertise et aux technologies américaines et britanniques, brisant fortement le caractère indépendant de la bombe