HAL Collection UNC (Univ. de la Nouvelle Calédonie)
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Innovative Solutions Developed in the Pacific. Nature-based and Engineered Solutions: Arbuscular mycorrhizal fungi as potential regulator of Climate change impact on Medicinal and Aromatic Plants metabolome
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Renewable Resources for Sustainable Power Generation: Green Synthesis of Zinc Oxide for Dye-Sensitized Solar Cells
No full textInternational audienceThe production of green energy represents a major challenge in the thematic of global climate change. Electricity production by photovoltaic solar cells is currently widely studied to develop low-cost devices such as Gratzel dye-sensitive solar cells or peroxide solar cells in improve their performance compared to the classic silicon cell. The Gratzel dye-sensitive solar cells are made up of a dye, a semi-conductor as zinc, titanium or nickel oxide and an electrolyte solution. The dye can produce electrons when excited by light, the electrons are captured by the semiconductor oxide and passed to the electrical circuit to which the cell is connected. The electron is regenerated bye an electrolyte as iodide solution in the main case. The production of semi-conductor oxide or dye with a lower cost and the efficiency of dye or the capacity of the semi-conductor are still current challenge. In his study, we investigate the preparation of zinc oxide by classic sol gel process and green chemistry in natural organic media. The sol gel synthesis is carried out by polyol process or by classic precipitation in basic media followed by a step of calcination `a 600 ◦c. We study the doping of zinc oxide with nickel or cobalt ions in order to modify the band gap of the zinc oxide-based semiconductor to improve its electron capture capacity. The particle size is controlled by modifying the synthesis parameters (metal ion/base ratio). Zinc oxide particle are characterized by X-ray diffraction transmission electron microscopy and UV-visible spectroscopy. The synthesis of zinc oxide particles by green chemistry is achieved by reduction of a zinc cation by a reducing natural products and calcination at 600◦C. The influence of several natural extracts from organic waste biomass (green and black tea, cocoa, coffee) on the synthesis yields and properties of zinc oxide particles was evaluated. Untargeted metabolomics approaches based on mass spectrometry were employed to identify the molecular structures involved in the green synthesis process
Impact of Control Interventions on Malaria Incidence in the General Population of Mali
No full textInternational audienceBackground: The increase in malaria incidence and the reduction of funding for malaria control have highlighted the need to step up efforts in the fight against malaria in Mali. To further refine the malaria control strategy implemented in the country, this study aimed to evaluate the impact of control interventions at the health district level on malaria incidence in the general population.Method: Malaria, rainfall, and intervention data were collected for the 75 health districts of Mali for the period from April 2017 to March 2022. The impact of the different control interventions on malaria incidence in the general population was assessed at the health district level with a Generalized Additive Mixed Model considering rainfall.Results: Although coverage rates varied widely between health districts, most interventions showed an improvement in coverage over the study period. Two interventions had a small impact on incidence: long-lasting insecticidal net mass distribution (LLIN), with a reduction rate of 2.2 ‰ for an adjusted coverage rate from 30.0 to 79.0% (odds ratio (OR): 0.998; 95% confidence interval (CI) 0.997-0.999), and seasonal malaria chemoprevention (SMC), with a reduction rate of 1.9 ‰ for an adjusted coverage rate from 30.0 to 80.0% (OR: 0.9979; 95% CI 0.996-0.998).Conclusion: The analysis found a small impact of LLIN and SMC on malaria incidence at the district level. Malaria control should be reinforced by improving coverage and utilization rates in the general population and in the most vulnerable groups and by deploying larger numbers of community health workers where needed
Cryptic Diversity and Genetic Differentiation of Mesophotic Hydroids in the Southwestern Indian Ocean
No full textInternational audienceThe western Indian Ocean (WIO) is recognized as a marine biodiversity hotspot with complex oceanographic circulation resulting in limited connectivity between remote islands. This ocean region comprises several subregions of varying biodiversity, with the northern Mozambique Channel standing out as the core of this hotspot. Although the hydroids in this region are known to include cryptic species and show contrasting connectivity patterns, the mesophotic depths remain largely unexplored. The Deep Reef Refuge Hypothesis suggests that mesophotic coral ecosystems may act as refuges. However, this hypothesis is based on several prerequisites that could be affected by the presence of cryptic species. We investigated the genetic diversity and connectivity of seven hydroid species by collecting samples at euphotic and mesophotic depths around the islands of Mayotte and Reunion. Population genetic patterns were investigated using multivariate analyses and Bayesian clustering, with 8-18 microsatellite markers per species. The results revealed greater genetic diversity in Mayotte than in Reunion, even though fewer samples were collected there. This is in line with the location of the heart of the hotspot in the northern part of the WIO. In addition, all species exhibited strong genetic differentiation between samples from the two islands, supporting the "one island, one species" hypothesis previously proposed for hydroids in the region. However, contrasting values were obtained among depths depending on the species and the island, demonstrating the importance of a multi-species approach. The inclusion of mesophotic samples from the Taxella eximia/gracilicaulis and Macrorhynchia phoenicea species complexes provides new insights into the true biodiversity of these genera, revealing additional cryptic species and putative hybridization. Furthermore, the genetic connectivity estimation performed here among depths highlights several species that could be evaluated in terms of the vertical connectivity prerequisite of the Deep Reef Refuge Hypothesis in Mayotte and Reunion
Comparative Analysis of Geometries of Interdigitated Capacitive Sensors for Liquid Media Detection
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Au-delà des formules, qu’entendons-nous par « pédagogie sensible » et qui écoutons-nous dans « pluralités sociales » ?
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SIMONE: Semantic Representation of Model Outputs for Scientific Knowledge Graph Enrichment
No full textInternational audienceThe amount of observational data has increased in part due to the more affordable devices and the open satellite data providers. Diverse organisations and working groups have proposed modelling strategies to structure observational data according to their particular purposes. For instance, the ontology I-ADOPT is used to model the detailed description of experiment variables, whereas the ontology SOSA is used to model sensors, instruments and measurements. However, a vast amount of data lies outside the realm of observed data, as is the case with derived, calculated, inferred, predicted, or simulated data. Although both derived outputs and observations share multiple characteristics (e.g., date, value, units, feature of interest, etc.), to our knowledge, there is a lack of a standard model that considers these similarities when describing derived outputs. To fill this gap, this study explores the various representation requirements and introduces SIMONE, a semantic profile based on the semantics of standards such as SOSA and I-ADOPT. We demonstrate the utility of this modelling strategy with a real-life use case concerning the prediction of species coverage for multiple forest areas in Europe.</div