HAL Collection UNC (Univ. de la Nouvelle Calédonie)
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The elaboration of culturally and locally based mathematics curricula in a globalized context
No full textInternational audienceIn many different indigenous societies around the world, the elaboration of a culturally and locally based mathematics curriculum has been undertaken as part of the decolonization process. These indigenous societies have increasingly come to recognize the value of their traditional knowledge and practices by resorting to them in formal education. One can sometimes perceive here, a tension between two contradictory goals related to local and global concerns respectively. On the one hand, such culturally based mathematics curriculum would aim at valorizing indigenous knowledge and practices within the local educational system. On the other hand, such a curriculum can be implemented with the underlying idea that it should increase the local students’ academic competence in mathematics. This paper will tackle these issues by focusing on two case studies related to the current educational changes in the Republic of Vanuatu (South Pacific) and in the Brazilian Indigenous Intercultural Education of the Paiter people. Both case studies thus seem to indicate that the relationship between global curriculum and local curriculum is traversed by different tensions. This paper will highlight the common and distinctive features of both case studies, in the implementation of culturally and locally based curricula in these two geographically and culturally distant areas
Very-High Resolution Coral Reef Habitat Mapping using Pleiades Satellite Imagery in Mayotte, Indian Ocean
No full textInternational audienceTropical coral reefs are the most biodiverse ecosystems on the planet. Unfortunately, increasing direct (e.g., overfishing, change in land use) and indirect (e.g., ocean acidification, sea-level rise, global warming, storms) human pressures are causing rapid declines in marine biodiversity globally, calling for more careful monitoring of sensitive ecosystems. If environmental baseline data like marine habitat maps are increasingly required to manage coastal environments, they are often lacking or are only available at a resolution that do not meet the needs of management. Such deficiencies hamper the implementation of effective management strategies and monitoring efforts.Here, we developed a method for conducting very high-resolution (sub-meter) mapping of benthic habitats semi-automatically across the 195km of Mayotte’s reef flat, a French island of the southwestern Indian Ocean. The mapping was performed using 50-cm resolution Pleiades satellite imagery from 2021-2023 and LiDAR-derived bathymetry. Satellite images were supplemented by underwater images acquired along 185 transects using a GoPro camera fixed to a diver propulsion vehicle. To achieve a very high spatial accuracy, underwater images were positioned with a few centimeters accuracy using a Global Navigation Satellite System (GNSS) system and post-processed kinematic (PPK) corrections. Geo-referenced image frames were extracted from the videos and integrated for annotations into CoralNet, a free online benthic image analysis software using semi-automatic deep learning analysis. About 10% of the video frames (3045 images) were annotated, allowing the analysis of over 27,000 image and calculate habitats’ covers on the reef. Satellite images were segmented using an Object-Based Image Analysis (OBIA) approach (i.e., the "Large-Scale Mean-Shift" (LSMS) segmentation method) and segments properties were used with other variables in a Random Forest pixel-based classification. To ensure replicability, data processing and analyses were conducted using free and open source software Orfeo ToolBox, QGIS, and R Stats.Thirteen benthic habitats, extending from coastal mangroves to the outer reef slope, were mapped at the pixel level. The LSMS segmentation method applied to Pléiades images created54,706 segments. CoralNet classifiers achieved 65% accuracy, while the Random Forest models reached an accuracy of 76%. The composition of benthic assemblages varied significantly aroundthe island, with changes in live corals accompanied by a rise in muddy habitats, turf, and dead corals as anthropogenic pressures intensify.The detailed habitat maps produced through this project will serve as an essential management tool to inform the management of Mayotte’s coastal waters. In December 2024, Mayotte experienced the very destructive Chido cyclone that strongly impacted the island, its population, and its terrestrial and marine ecosystems. By using satellite images acquired just before the cyclonic event, maps can serve as reference data, and help assess the cyclone's impact on the island's marine ecosystems
Designing policies to reduce the carbon footprint of mini-grids in Africa
No full textInternational audienceMini-grids with a low carbon footprint are a promising solution for providing electricity in rural areas, while being compatible with the objectives of the Paris Agreement. Public policies are needed to encourage their development and their design should consider the different point of view from each stakeholder involved in mini-grid projects (State, developer, users). We propose a multi-criteria approach to evaluate a set of policies to limit the carbon footprint of mini-grids. Our method is based on the simulation of fictitious mini-grids and on the calculation of four indicators: the mitigation cost, the policy cost, the average levelized cost of energy (LCOE) at the national level, and the disparity of individual mini-grid LCOE within the country. We applied the methodology to Senegal, Madagascar, Kenya and Nigeria chosen for the diversity in solar resource and fuel price. Our results advocate for the combination of fuel tax and subsidy on solar panels and batteries to further reduce the carbon footprint of mini-grids. Using fuel tax revenues to equalize the LCOE of mini-grids within a country allows a cost-efficient reduction of the carbon footprint while reducing the cost disparities between mini-grid projects
A typology of giant clam shell deposits in eastern Tuamotu-Gambier atolls (French Polynesia) to guide conservation and exploitation measures
No full textInternational audienceSince 2007, presence of mapiko and beaches of natural detrital accumulations composed mainly of giant clam valves are legal criteria to formally identify atoll lagoons where giant clam mariculture should be ecologically sustainable and authorized in the Eastern Tuamotu-Gambier Archipelago (French Polynesia). Mapiko is a vernacular east Tuamotu word that loosely refers to structures made of lagoonal giant clam shells. As such, there are ambiguities when interpreting the legal text, as shell deposits are of various sizes, in various locations and from different origins through on-the-spot accumulation or through storm-induced transport. To help solving the issue with a clear framework, the various types of carbonate deposits made of Tridacna maxima giant clam shells found in the Eastern Tuamotu-Gambier atoll lagoons are described. Nine atolls displayed a total of 10 aerial and underwater types of deposits primarily defined according to geomorphological locations, position relative to mean-sea level and compactness. Several of the aerial deposits could be mapped using very high spatial resolution satellite images to provide per atoll the number of deposits and their size spectrum. The atolls differed widely in terms of dominance and abundance of deposit types. The genesis of these unique structures is discussed, although no dating is available to confirm the processes. Nevertheless, the role of factors ranging from cyclones to mass mortality events and to fishers’ behaviors can be highlighted for the different deposit types. The 10-class typology of giant clam shell deposits provides a new referential to define the entities of shell deposits that legal texts can refer to, to eventually better manage atoll lagoons. Changes in the legal text are also suggested to take into account the recent changes due to massive mortalities that have plagued some lagoons, turning in some cases accumulation of live giant clams into new deposits of dead shells
Metabolomics Signatures of a Respiratory Tract Infection During an Altitude Training Camp in Elite Rowers
No full textInternational audienceBackground: Respiratory pathologies, such as COVID-19 and bronchitis, pose significant challenges for high-level athletes, particularly during demanding altitude training camps. Metabolomics offers a promising approach for early detection of such pathologies, potentially minimizing their impact on performance. This study investigates the metabolic differences between athletes with and without respiratory illnesses during an altitude training camp using urine samples and multivariate analysis. Methods: Twenty-seven elite rowers (15 males, 12 females) participated in a 12-day altitude training camp at 1850 m. Urine samples were collected daily, with nine athletes developing respiratory pathologies (8 COVID-19, 1 bronchitis). Nuclear Magnetic Resonance spectroscopy was used to analyze the samples, followed by data processing with Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA), allowing to use Variable Importance in Projection (VIP) scores to identify key metabolites contributing to group separation. Results: The PLS-DA model for respiratory illness showed good performance (R2 = 0.89, Q2 = 0.35, p < 0.05). Models for altitude training achieved higher predictive power (Q2 = 0.51 and 0.72, respectively). Metabolites kynurenine, N-methylnicotinamide, pyroglutamate, propionate, N-formyltryptophan, tryptophan and glucose were significantly highlighted in case of respiratory illness while trigonelline, 3-hydroxyphenylacetate, glutamate, creatine, citrate, urea, o-hydroxyhippurate, creatinine, hippurate and alanine were correlated to effort in altitude. This distinction confirms that respiratory illness induces a unique metabolic profile, clearly separable from hypoxia and training-induced adaptations. Conclusions: This study highlights the utility of metabolomics in identifying biomarkers of respiratory pathologies in athletes during altitude training, offering the potential for improved monitoring and intervention strategies. These findings could enhance athlete health management, reducing the impact of illness on performance during critical training periods. Further research with larger cohorts is warranted to confirm these results and explore targeted interventions
Déwé Gorodé traductrice de Grace Mera Molisa : (re)construction d’une solidarité océanienne
No full textInternational audienceEn 1997, Déwé Gorodé revient à la poésie en traduisant une sélection d’œuvres de la poétesse vanuataise Grace Mera Molisa. Ce retour au genre poétique, qu’elle avait délaissé au profit de la fiction entre 1994 et 1996 avec deux recueils de nouvelles, marque une étape charnière dans sa trajectoire littéraire et politique. La traduction de poèmes issus des recueils Black Stone I et II ainsi que Local Global, semble préparer Gorodé aux responsabilités qu’elle assumera dès 1999, en devenant membre du gouvernement de la Nouvelle-Calédonie. Dans la préface de cette anthologie, sobre et engagée, Déwé Gorodé souligne : « Cette traduction est d’abord un témoignage et une modeste contribution au combat de Grace, celui des femmes du Vanuatu, du Pacifique et d’ailleurs. » Cet acte de traduction dépasse donc le simple geste littéraire pour s’inscrire dans un projet politique plus large, orienté vers la solidarité océanienne et l’émancipation des femmes. Cette communication se propose, dans un premier temps, d’étudier en parallèle les trajectoires croisées de Déwé Gorodé et Grace Mera Molisa, deux figures majeures de la littérature et de l’engagement océanien. Dans un second temps, elle analysera les choix de poèmes opérés par Gorodé et leurs implications. Nous montrerons comment cette sélection s’inscrit dans une vision programmatique où littérature et politique se rencontrent pour construire un espace de solidarité féministe et océanienne
P04-12 Effects of 5G exposure on gene expression of browning in TRPM8 knockout mice
No full textInternational audienceIntroduction:The rapid expansion of radiofrequency (RF) in telecommunication raises concerns about possible health impacts. Previous studies have shown that radiofrequency exposure at low intensity of 900 MHz (2G) can induce a cold sensation and a thermal preference for warmer environments 1, 2, 3. These results suggest thermoregulatory responses that could trigger the activation of thermogenesis as the browning in white adipose tissue and the implication of TRPM8, an important receptor implicated in the cold sensation [4]. The aim of this study is the evaluation of the impact of 3.5 GHz (5G) RF exposure on UCP1 thermogenic pathway and the interaction between 5G exposure and the TRPM8 cold sensor using TRPM8 knockout (KO) mice.Methods:Adult C57BL/6J, wildtype (WT) and TRPM8 KO female and male mice (n=12) were randomised into 2 subgroups (n=6): 5G group (3.5 GHz), and control group (SHAM). 5G groups (male and female) were exposed twice a day for 7 days at an intensity of 1.5 V/m at 3.5 GHz for one hour. The specific absorption rate (SAR) was calculated at 30 mW/kg. At the end of exposure period, white adipose tissue (WAT) was collected and RT-qPCR was carried out on genes implicated in the thermogenic pathway (UCP-1, PPAR-alpha, PPAR-gamma, PRDM-16, DiO2, S100b, PGC1-alpha, ADRB3, Irisine and Cidea). An analysis of variance test followed by a Mann-Whitney test were used for statistical analysis to evaluate the effects of 3 factors: sex (male vs female), RF exposure (5G vs sham) and genotype (KO vs WT).Results:There is no modification in expression of UCP1, PPAR-alpha, PGC1-alpha, PRDM16, S100b, Di02, ADRB3 and Cidea genes. The 5G exposure increases the expression of Irisine, regardless of the sex and genotype of mice (+75.9%, p=0.002). The expression of PPAR-gamma in female exposed groups increases compared to female sham groups (+51.2%, p=0.03) and compared to male exposed groups (+62.3%, p=0.03). Moreover, the expression of PPAR-gamma is overexpressed in TRPM8 KO exposed groups compared to TRPM8 KO sham groups (+51.8%, p=0.01) and compared to WT exposed groups (+81.2%, p=0.001).Conclusion:Our results show an overexpression of 2 markers (Irisine and PPAR-gamma) implicated in the browning of WAT. This process is currently activated by a cold stimulation to increase the production of heat. Thus, we confirm that RF exposure, particularly 5G signal, induce physiological responses similar to those activated by cold stimulation
Preliminary evidence that thermally inactivated mycelium improves water resistance of biostabilized earth materials
No full textInternational audienceEarth-building materials offer a low-carbon option for construction, but their poor water resistance limits their adoption by the construction industry. Adding biopolymers to earth materials can improve mechanical strength and water resistance but also promote mold mycelium growth that reduces indoor air quality. However, for other applications such as insulation or packaging, the controlled growth of specific mycelium is seen as a promising option for producing natural waterproof materials. These application require heat-inactivation to kill the mycelium and preserve air quality. It is currently unknown if heat-inactivated mold mycelium could improve the water resistance of earth materials. This study explores a new design by promoting the natural growth of molds on biostabilized earth materials and studying the effect on earth material properties after heat inactivation. Earth mortars were prepared by mixing soil, water, and biopolymers (2 % of soil mass) to a consistent texture. Twenty formulations, using two soils and four biopolymers, were subjected to two different 21-day cures, under dry (oven at 50 • C) or humid (30 • C, 98 % RH) conditions. Mortar properties were investigated after a 48-h 80 • C heat treatment to inactivate mold. We found that the humid cure consistently prompted mold growth on biostabilized mortars, which was associated with significantly higher water resistance compared to unexposed mortars. Specifically, capillary water absorption and mass loss after water spray was reduced by 28 % and 64 % respectively. These improvements were achieved with minimal impact on shrinkage, density, and mechanical strength. The amelioration in water resistance was attributed to the hydrophobic mold mycelium filling the earth mortar pore as observed by UV microscopy. Together, this study demonstrates that mycelium could dramatically improve the water resistance of biostabilized earth materials
An Integrated Assessment of Microplastic Pollution in Coastal Surface Water and Sediment of Japan
No full textInternational audienceThe ubiquity of microplastics in the marine environment has been highlighted in recent years, yet the extent of microplastics pollution in coastal areas, especially off the coast of Japan, remains unclear. Here we provide a comprehensive dataset of microplastic pollution in surface water and sediment around coastal Japan. The survey encompasses 15 locations along Japanese coasts from the northernmost in Hokkaido to the southern archipelago of Okinawa.The mean microplastic concentration was 288.7 ± 651.6 g km 2 and 1,185 ± 3,829 kg km 2 for surface water and sediment, respectively. A total of 53,466 particles were extracted from both sediment and surface water as suspected microplastics using a series of sieving, density separation and digestions. Using Fourier Transform Infrared Spectroscopy, 11,587 particles (21.7% of the total number of suspected microplastics) were chemically characterized of which 85% of particles from surface water were identified as plastics and 70% in sediment. The main polymers found were the widely used polyethylene, polypropylene, and polystyrene. Analysis of sources and pathways of microplastics revealed that rainfall, population, aquaculture and fisheries were major drivers of microplastic concentrations. This comprehensive survey highlights the rapid sinking of microplastic in coastal areas and the urgent need for better waste management associated with marine activities especially in rural areas.</p