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Shedding lights on the diversity and nutritional benefits of small dried fishes in Madagascar
No full textOne Ocean Science Congress, Nice, FRA, 03-/06/2025 - 06/06/2025Madagascar is renowned for its wide range of aquatic organisms, particularly crabs, octopus and fish. The latter are particularly abundant and are sold in a variety of forms (fresh, salted, smoked or dried) and sizes, ranging from large to small individuals. Small dried fish (SDF) are abundant and omnipresent across Malagasy markets. However, they remain poorly understood in terms of their cultural and taxonomic diversity, as well as their nutritional benefits. As an accessible and affordable food source, SDF could help alleviate micronutrient deficiencies, a major issue in Madagascar. In this study, we explored the diversity and nutritional importance of SDF sampled at 16 markets and 12 towns along the National Road 7, which connects Toliara (coast) to Antananarivo (inland). For that purpose, we combined: (i) a socio-economic survey of 112 vendors, (ii) taxonomic (traditional and molecular) analyses to identify the diversity of fish species sold across 131 batches of SDF, and (iii) nutritional and heavy metal analyses of the 10 most popular batches. We assessed their the potential intake of key nutrients and heavy metals from SDF and contribution to Recommended Dietary Allowance (RDA) and maximum Tolerable Weekly Intake (TWI), respectively, considering daily? portions of 10 g for infants (7-11 months) and 20 g for both children (1-3 years) and women of childbearing age (15-50 years). We identified 43,819 individual fish specimens corresponding to 8.1 kg across the 131 batches sampled. These specimens were classified into 233 morpho-species belonging to 110 genera and 61 families, with the Clupeidae, Engraulidae and Poeciliidae families being the most represented in terms of both biomass and abundance. Thirty distinct types of SDF were characterized, of which 19 are commonly consumed by humans, such as the freshwater fish varieties Pirina and Varilava, with appreciation rates of 89% and 83% respectively. SDF are mainly consumed with rice, cassava or maize, and are generally prepared in sauces, fried or mixed with leafy vegetables. Consumption of SDF provides essential nutrients for humans. Across the three population groups, SDF contribute at least 30% of the RDA for selenium, calcium, phosphorus, magnesium and iron. For infants, a 10g portion could meet more than 81% of daily calcium and selenium RDA. Most SDF also provide more than 42% of the RDA for iron and 29% for manganese. For children 1-3 and women of childbearing age, a 20 g portion covers more than 100% of the RDA for calcium, selenium and iron, particularly for the Matsiroky, Kalatambo and Ambotsika types of SDF. In all groups, contributions to potassium, copper and zinc RDA were moderate. Vitamin A was not detected in the ten SDF lots, except for a small trace in Ambotsika. Some types of SDF (Matsiroky) exhibited by significant traces of arsenic, cadmium and lead, requiring moderate consumption. This study enhances our understanding of the potential role of SDF in health and nutritional security and identifies the types most likely to improve nutritional outcomes for the population.Key words: Small dried fish, micronutrients, heavy metals, Recommended Dietary Allowance (RDA), food security, Madagascar
Montagne et Haute-Montagne dans l'espace des anciens Etats de Savoie: Actes du 49e Congrès des Sociétés Savantes de Savoie
No full textInternational audienc
Vulnerable but not equal: Mountain lakes exhibit heterogeneous patterns of phytoplankton responses to climate change
No full textInternational audienceAbstract While climate change affects the phytoplankton biodiversity at both local and global scales, predicting phytoplankton community responses to warming is impaired by their polyphyletic complexity. High mountain lakes are highly vulnerable systems, partly due to their limited biodiversity, and forecasting their ecological trajectories is a key challenge for scientists and conservation managers. We evaluated the phytoplankton's sensitivity to temperature in 24 high‐altitude lakes over a multi‐year (average 7‐year) study. We detected assemblage‐specific responses to warming, with different trends in biovolume and diversity observed among the diatom‐dominant, mixed‐mixotrophs dominant, and colonial‐green dominant assemblages. The environmental settings partly governed assemblage responses, highlighting the role of the landscape filters in determining the response to warming. The biological stability of lakes, that is, their ability to resist shifts in their phytoplankton assemblage, is therefore determined both by the lake characteristics and warming intensity
Profils et trajectoires des ménages accédant à la propriété de leur logement social : quand les expériences de l’accession sont le révélateur d’inégalités (criantes) face au logement.
No full textWhile the sale of social housing is an economic lever enabling social housing landlors to (modestly) increase their financial resources in order to continue producing housing, it raises a number of questions from the point of view of the purchasers of these dwellings and their occupants. Based on an ethnographic survey among 20 households who were formerly social housing tenants and had become homeowners through the sale of social housing, the survey sought, from an emic perspective, to understand the determinants of these purchases in terms of residential pathways and biographical trajectories. From a sociological point of view, the purchase of social housing can be analysed by taking into account the social classes relations, logics of social distinction, relationship with the neighbourhood, socio-economic aspects of the purchasers, family trajectories and residential mobility as well as their imbrications in the field of employment in a context of uncertainty. One of the main objectives of this research is therefore to document, from a sociological perspective, the profile of these purchasers on the different sites (economic, social, family and generational profile). This approach makes it possible to address the social, emotional and economic dimensions of the experience of buying a social housing property, from buyers’s perspective. We therefore looked at how getting to be an owner affects the relationship with oneself and the domestic economy. In the light of what we heard from the 60 households surveyed (20 in the Bouches du Rhône, 20 in Limoges and 20 in the Paris suburbs), we asked ourselves: To what extent, and under what conditions, can ownership of social housing be seen as a step up the housing ladder? On the other hand, under what circumstances, and on the basis of biographical and residential trajectories, can home-ownership be costly for the households involved?The fieldwork made it possible to reveal the subjectivation work carried out by the respondents. Because the families in the survey had experienced home ownership at a time when, on the one hand, most of them were excluded from home ownership via the private sector and, on the other hand because they experienced housing difficulties in their biographical and residential trajectories, they refocused the subject of this research on the question of inequalities toward housing. The field work reveals a particularly burning issue consecutively to the gender dimension.Si la vente de logements sociaux constitue un levier économique permettant aux bailleurs d’accroître (modestement) leurs ressources financières pour continuer à produire du logement, elle pose un certain nombre de questions du point de vue des acquéreurs de ces logements et de leurs occupants. A partir d’une enquête ethnographique auprès de 20 ménages, anciens locataires du parc social et ayant accédé à la propriété via la vente de logements sociaux, l’enquête a cherché, dans une perspective émique, à comprendre les déterminants de ces achats à l’aune des parcours résidentiels et des trajectoires biographiques. Du point de vue sociologique, l’accession à la propriété d’un logement social peut être analysée en prenant en compte les rapports de classe générée par cette dernière, les logiques de distinction sociale, les rapports au quartier, les aspects socio-économiques des accédants, les trajectoires familiales et les mobilités résidentielles ainsi que leurs imbrications dans le champs de l’emploi dans un contexte d’incertitude. L’un des principaux objectifs de ce travail de recherche est donc de documenter, d’un point de vue sociologique le profil de ces acquéreurs sur les différents terrains, (profil économique, social, familial, générationnel). Cette démarche permet d’aborder la dimension sociale, affective et économique de l’expérience de l’accession à la propriété d’un logement social, et ce, du point de vue des accédants. Ainsi, nous nous sommes intéressés à ce que fait l’achat d’un logement social au rapport à soi, à l’économie domestique ou encore au rapport à l’habiter. Dans quelle mesure l’accession à la propriété d’un logement social peut-elle être vécue comme une ascension résidentielle et à quelles conditions ? Au contraire, dans quelles circonstances et à partir de quelles trajectoires biographiques et résidentielles, cette accession à la propriété peut-elle être coûteuse pour les ménages accédants ?Le travail de terrain a permis de dévoiler un travail de subjectivation de la part des enquêtés au sujet des inégalités face à la propriété et face au logement. Parce que les familles de l’enquête ont expérimenté l’accession à la propriété alors que, d’une part, la plupart d’entre elles étaient exclues de l’accession via le secteur privé et, d’autre part, qu’elles ont pu connaître dans leur trajectoire biographique et résidentielle des difficultés pour se loger, elles ont ainsi recentré le propos de cette recherche autour de la question de ces inégalités. Cette question des inégalités face au logement et à l’accession a été dévoilée par le travail de terrain particulièrement à l’aune de la dimension genrée de cette expérience
Thresholds of functional trait diversity driven by land use intensification
No full textInternational audienceIt is unclear how much land use intensification ecosystems can withstand before undergoing abrupt changes in their structure and dynamics. Here we assess how the functional structure, diversity and temporal stability of 150 agricultural grasslands responded to large variations in land use intensification, namely, different intensities of fertilization, grazing and mowing. Using multi-site time series (2008–2020) of plant trait distributions, we identify two thresholds where the functional structure, diversity and stability of grasslands changed dramatically. The first threshold occurred between unfertilized and fertilized grasslands, with maximization of trait evenness indicating the persistence of plant species with diverse resource-use strategies in extensively managed grasslands. The second threshold occurred when fertilization exceeded 80 kg N ha−1 yr−1 or when grazing exceeded 500 livestock units days ha−1 yr−1, beyond which the most intensively managed grasslands were functionally poor, highly unstable and vulnerable to extreme weather events. These findings allow us to quantify the level of perturbation beyond which grasslands depart from a high biodiversity state and show that highly intensive management pushes the system to a more unstable state. The identified thresholds may provide targets for sustainable management and fertilization practices
Mathieu Deldicque, Le dernier commanditaire du Moyen Âge. L’amiral de Graville Vers 1440-1516
No full textInternational audienc
A deletion in a photosynthesis-related gene (PpPSAK) determines the anthocyanin accumulation in the mesocarp of French blood-flesh peaches
No full textInternational audienceAccumulation of anthocyanin pigments is a primary determinant of fruit quality in peach (Prunus persica L. Batsch). The recessive blood-flesh trait (bf), identified in French cultivars was first mapped on chromosome 4. However, the underlying gene is yet to be identified. In this study, the genetic, molecular and transcriptional bases of the bf trait were investigated. Blood-flesh cultivars showed high levels of cyanidin-3-glucoside and cyanidin-3-rutinoside in the fruit mesocarp about 45-60 days after anthesis. Fine mapping coupled to a positional cloning strategy mapped the bf locus to an 80-kb interval on peach linkage group 4. The sequence polymorphism analysis of genes present in this interval allowed the identification of only one candidate gene for bf a deletion of 21-bp in exon 3 of a PSAK-like gene (PSAK:photosystem I subunit K). A specific marker for the deletion was developed and validated in different genetic backgrounds. An expression study of PpPSAK as well as analysis of structural, regulatory and photosynthesis related genes was performed to compare cultivars with blood-flesh (Montarsa) and without blood-flesh (S11332) during fruit development from 60 days after blooming until fruit maturity. Differently expressed of PpPSAK in the flesh of bf fruit was correlated with expression of anthocyanin biosynthesis structural genes. A protein-protein interaction study was performed and is presented with an open discussion on functional pathways in peach
Relation entre la source de Fontaine de Vaucluse et le forage de Vallon de l'oule
No full textEn novembre 2024, une opération de nettoyage et de développement d'un forage proche de la source de Fontaine de Vaucluse a été menée. Des prélèvements d'eau destinés à être analysés chimiquement (ions majeurs, carbone organique total, isotopes stables de l'eau, tritium et carbone 14) ont été réalisés au cours des pompages.Ce document présente de façon pédagogique les résultats de l'étude, qui mettent en évidence une connexion entre le forage et la source
Plateforme frugale à ondes acoustiques pour la détection biochimique in situ
No full textLa Commune de Sinnamary en Guyane Française porte le projet de Centre d’Interprétation de l’Eau et des Milieux Aquatiques (CIEMA) de Guyane.Il consiste à faire évoluer la structure actuelle de la Maison de la nature des marais de Yiyi. Ses objectifs stratégiques sont :La préservation de l’écosystème,L’étude des impacts du changement climatique sur les zones humides,La découverte de l’eau et des milieux aquatiques,Le développement de l’éducation à l’Environnement et la citoyenneté pour l’eau,La mise en tourisme du site.Un séminaire de travail avec toutes les parties prenantes réunies, se tiendra les 30 et 31 octobre 2023, dans le but de structurer et de finaliser le projet.International audienc
Elevational range shifts among Bombina toad populations in the Alps in response to future climate change
No full textInternational audienceThe ability of species to cope with climate change depends on both intrinsic and extrinsic factors, for instance dispersal ability and landscape composition. Nevertheless, populations can also differ in their ability to track the shift of suitable areas due to traits developed in response to local environmental pressures. In the south-west part of the distribution area of the yellow-bellied toad (Bombina variegata), two divergent ecotypes, named fast and slow, can be identified along a gradient of anthropization. We investigate the ability of these ecotypes to track the altitudinal shift of suitable habitat in the French Alps at the horizon 2100. First, we modelled future climatic suitability in the Alps according to climatic scenarios, and then we used a process-based model simRShift, to simulate the demographic and colonisation processes in the future accounting for the traits of each ecotype. The fast ecotype may not persist and colonise as many habitats compared to the slow ecotype (e.g. 872.3km2 and 4200.2 km2 under the optimistic scenario in 2100 for the GFDL-ESM4 GCM respectively for fast and slow). We explain these results by the shorter lifespan of the fast ecotype that makes it more vulnerable to stochasticity