HAL-Université de Bretagne Occidentale
Not a member yet
75442 research outputs found
Sort by
Les vulnérables ou hypervulnérables : réflexion à partir de la comparaison entre le droit français et le droit brésilien
No full textInternational audienc
Participatory Monitoring Tool to Assess the Sustainability of Tilapia (Oreochromis niloticus) Fish Farming in West Africa
No full textInternational audienceSustainable freshwater aquaculture is crucial for food security and economic development in Africa, particularly in North West Africa's less advanced countries. Existing complex monitoring methods are often impractical for these contexts due to technical and resource limitations. We developed and tested a localised tool to evaluate the sustainability of tilapia farms across diverse agroecological zones in Senegal. The approach involved engaging farmers in a participatory process to identify context-relevant indicators for the environmental, social, and economic dimensions of tilapia farming. These indicators were scored to create a composite sustainability index. Key sustainability challenges identified included a lack of technical support, profitability issues, inadequate environmental management, and social welfare concerns. However, we found promising potential for integrated community-based farms. The sustainability indicators inform policies and practices that promote localised sustainability in sub-Saharan Africa, while considering smallholder farms' unique needs and characteristics. These assessments contribute to implementing targeted interventions, improved resource management, and enhanced social and environmental outcomes in the freshwater farming industry. Collaboration and knowledge sharing among stakeholders can significantly contribute to developing sustainable aquaculture practices, though successful implementation requires specific, medium-term practice programmes. The tool successfully discriminated between farm types, with intensive private farms scoring highest overall (up to 73% of the maximum sustainability score), while extensive farms in the southern region scored lowest (≈40%). The study demonstrates the value of participatory, context-specific tools for diagnosing sustainability and guiding improvements in African aquaculture
Complexity and transdisciplinarity in Earth system scienceand education in the Anthropocene.
No full textInternational audienc
Areas susceptible to desertification in Brazil: An approach based on the frequency of annual aridity classes
No full textInternational audienceThe expansion of arid lands is one of the most critical environmental threats of the century, driven by climate change and unsustainable human activities. In Brazil, recent climatic shifts suggest an expansion of arid and semi-arid zones beyond the traditionally vulnerable Northeast region. While prior research has emphasized long-term climatological trends focused in that region, this study adopts non-stationary approaches to examine year-by-year aridity class frequencies from 1961 to 2020 across the entirety of Brazil. It also distinguishes the relative influence of precipitation (P) and potential evapotranspiration (PET) on observed aridity index (AI) changes. Our results reveal an expansion of roughly 30 % of dryland conditions across Brazil over the past 30 years, extending beyond the traditionally semi-arid Northeast into the Southeast, and an emerging hotspot in the Pantanal, potentially linked with larger scale South American aridization trends. The increasing annual frequency of arid and semi-arid classifications, particularly in emerging zones, suggests a persistent shift towards drier climates. This pattern seems to be driven primarily by declining P and secondarily by rising PET (temperature). By analyzing annual frequencies, we uncover a creeping aridity process, which directly converses with updated desertification risk assessments and climate adaptation strategies in Brazil, such as the ‘Brazilian Action Plan to Combat Desertification and Mitigate the Effects of Drought’
Profil d’une séance orientée investigation : impact d’un résultat de recherche sur la réflexion d’une enseignante
No full textInternational audienc
Membrane fingerprints and morphotype shifts in Phaeodactylum tricornutum co-exposed to cadmium and PBAT macroplastics as ecotoxicological indicators
No full textInternational audiencehis study investigates the individual and combined effects of cadmium (Cd2+) and poly (butylene adipate-co-terephthalate) (PBAT), a biodegradable macroplastic, on the marine diatom Phaeodactylum tricornutum (P. tricornutum). Interestingly, co-exposure with PBAT mitigates Cd2+ toxicity, except at high Cd2+ concentrations. Using a non-invasive Fourier-transform infrared (FTIR) spectroscopy protocol with robust acquisition parameters and principal component analysis, specific biochemical changes in membrane composition were monitored, with notable decreases in carbohydrate and lipid contents, while protein levels remained unaltered. Morphological observations revealed a shift toward the oval morphotype under exposure to Cd2+ and PBAT, alone and in combination, featuring a stress response. Additionally, the light-harvesting pigments, chlorophyll-a and fucoxanthin, increased in a dose-dependent manner upon Cd2+ exposure, while no significant β-carotene changes were observed, except at high Cd2+ concentrations in the presence of PBAT. This effect is further amplified under co-exposure conditions, the presence of PBAT leading to a marked increase in all three pigments, β-carotene included. The experimental protocol, which involved the aging of PBAT macroplastics in seawater for a short period, suggests that the degradation products of PBAT themselves are responsible for these observed biological effects. It is worth noting that morphotype shifts occur at lower Cd2+ concentrations than those affecting photosynthesis and photoprotective systems. These findings highlight the potential of P. tricornutum membrane fingerprints and morphotype shifts as sensitive ecotoxicological indicators of metal and plastic pollution, particularly in relation to degradation by-products in marine environments
Sediment mixing across heterogeneous benthic habitats: environmental and faunal controls along multiple gradients
No full textInternational audienc
Effect of fly ash, basalt fibre and attapulgite nanoclay on the fresh properties, rheology and shrinkage behaviour of printable concrete
No full textInternational audienc
Les besoins de formation des cadres de santé
No full textNational audienceDans le cadre d’une étude sur le référentiel d’activités et de compétences du Cadre de santé (document de travail, DGOS, 2012) menée par l’IFPS-IFCS de Brest, une partie abordait des besoins de formation. Les réponses de 186 professionnels et de 35 étudiants mettent en évidence des besoins globalement similaires sauf pour les activités de soins. Les Cadres de santé expérimentés avancent une hiérarchie légèrement différente, et interrogent les modalités de mise en oeuvre de la formation continue. Un questionnement ouvert des étudiants -dernier trimestre de formation- conduit à questionner la structure d’un programme de formation appuyée sur le référentiel de 2012