122418 research outputs found
Sort by
Engaging, collaborating, and driving change within a multi-stakeholder platform through a step-by-step approach of innovation design applied to African dairy value chains
Get PDFIn Sub-Saharan Africa, dairy value chains' stakeholders face many challenges and have expectations for change. Step-by-step innovation design methodologies and multi-stakeholder innovation platforms are implemented to drive changes desired by stakeholders. We assumed that combining these two approaches would reinforce the potentiality of achieving the changes. To the best of our knowledge, the specific mechanisms and actions involved in such a combination are poorly documented. This study contributes to fill this gap by reporting on modalities of engagement, collaboration, and change generation with stakeholders of dairy innovation platforms deriving from a step-by-step innovation design approach that is embedded within an overall loop-structure dynamic and accounting for three levels of stakeholders' engagement. We applied this step-by-step approach as part of the “Africa-Milk project” on ten dairy innovation platforms located in four African countries (Senegal, Burkina Faso, Kenya, and Madagascar). The approach was led by a core team and applied adaptively across the various innovation platforms, according to both their organizational context and objectives. In this paper, we captured the lessons learned along the key implementation stages of the approach (i.e., engagement, action, and assessment) and regarding the type of stakeholders involved. Our results show that the initiation of the engagement highly depends on the pre-existence of an innovation platform. The action stage proceeds then through either cascading actions or parallel actions. Finally, the outcome assessment stage enables to identify different types of changes induced by the approach (i.e., changes in practices, interactions, capacities, and opinions). Owing to its adaptability, the overall loop-structure of the approach enables practical adjustments and reflexivity to best meet the needs of innovation platform stakeholders. This study paves the way to implement co-design of innovation approaches to broader multi-stakeholder platforms involved in agri-food system transformations
Toward a comprehensive analysis of pesticide use in Cambodian rice farming and identification of levers for its reduction
Get PDFThis article reports on pesticide use in rice production by 210 farmers across seven provinces in Cambodia along a gradient of intensification defined by the number of rice crops per year. Using descriptive statistics and thematic analysis of both qualitative and quantitative data, we compare rice production systems with one, two, or three crops per year. The level of pesticide use was assessed through spraying frequency and the type of pesticide used, the pests targeted by farmers, and their active ingredients. The results indicate varying intensities of pesticide use, with the highest application rates per cycle, particularly of insecticides, in the three-crop rice system. Farmers primarily rely on advice from local pesticide sellers for their choice of product and application rate and often mix different pesticides to enhance efficacy. Through on-site visits, 68 different active ingredients were identifiedd on the labels of pesticide packages stored on farms. Farmers expressed concern about the health and environmental risks associated with pesticide use. Our study highlights the complex relationships between agricultural intensification and pesticide use, as well as the importance of tailored extension services that offer information, education, and training to help farmers mitigate the risks of intensive pesticide use. It also underscores the need for ongoing surveys to document agricultural practices in evolving systems
Species grouping and diameter growth of trees in the Eastern Amazon: Influence of environmental factors after reduced-impact logging
Get PDFTree growth predictions still present a challenge to forestry scientists. Species richness, ecological behavior variations, and different climate and soil interactions make it difficult to predict and understand tree growth in managed forests. This study examined the relationship between soil, climate, and forest management parameters and tree growth, using data from more than 30 years of monitoring in the Brazilian Amazon. We evaluated all trees with DBH ≥ 20 cm in a database of 66,182 observations in 166 permanent plots, corresponding to 17,440 individuals and 642 species. We used the CAFOGROM growth model approach to analyze the dataset, and found 10 statistically distinct species groups in terms of tree diameter growth and maximal DBH for the species. Species classification based on ecological characteristics plays a crucial role in mitigating the impacts of treatment decisions and selective logging in forest management, making it possible to adopt appropriate practices and define logging intensities and cutting cycles compatible with conserving forest structure and species population. The model revealed variations in species growth resulting from the influence of factors including light, nutrients, and competition. Depending on the group, soil properties such as percentage of sand, silt, total carbon, presence of aluminum and phosphorus, and exchangeable bases or cation exchange capacity can accelerate or limit tree growth. However, no direct relationship has been found between specific soil and climate variables and an ecological group or tree size. Our study highlights distinct growth patterns among different species groups in response to reduced-impact logging and environmental variables. Effective forest management requires a nuanced approach, considering the varied growth responses of different species groups to ensure sustainable use and conservation of forest resources
A metagenomics survey of viral diversity in mosquito vectors allows the first detection of Sindbis virus in Burkina Faso
Get PDFArboviruses (i.e., Arthropod-borne viruses) pose a threat to human health worldwide. This taxonomically-diverse group includes numerous viruses that recurrently spread into new regions. Therefore, periodic surveys of the arboviral diversity in a given region can help optimize the diagnosis of arboviral infections. However, such surveys are infrequent, especially in low-income countries. Consequently, case investigation is often limited to a fraction of the arboviral diversity. This situation is likely to result in undiagnosed cases. Here, we investigated the diversity of mosquito-borne arboviruses in two regions of Burkina Faso. To this end, we used untargeted metagenomics to screen mosquitoes collected over three years in six urban and rural areas. The analysis focused on two mosquito species, Aedes aegypti and Culex quinquefasciatus, considered to be among the most important vectors of arboviruses worldwide. The screening detected Sindbis virus (SINV, Togaviridae) for the first time in Burkina Faso. This zoonotic arbovirus has spread from Africa to Europe. SINV causes periodic outbreaks in Europe but its distribution and epidemiology in Africa remains largely unstudied. SINV was detected in one of the six areas, and at a single year. Detection was validated with isolation in cell culture. SINV was only detected in Cx. quinquefasciatus, adding to the list of potential vectors of SINV in nature. The SINV infection rate in mosquitoes was similar to those observed in European regions experiencing SINV outbreaks. Phylogenetic analysis placed the nearly-full genome within a cluster of Central African strains of lineage I. This cluster is thought to be at the origin of the SINV strains introduced into Europe. Our results call for studies on the prevalence of SINV infections in the region to estimate the disease burden and the interest of SINV diagnostic in case investigation
Santé des plantes au sein des systèmes agroforestiers tropicaux, d'une approche systémique à la prise en compte des compromis entre services écosystémiques
Get PDFMes travaux portent sur la conception de systèmes agroforestiers tropicaux à base de plantes pérennes (caféier, cacaoyer, bananier) sous contrainte biotique (maladies et ravageurs) qui soient durable économiquement, socialement et écologiquement. J'explore la manière de mobiliser la biodiversité dans les systèmes agroforestiers, particulièrement les arbres d'ombrages, comme levier pour réguler les maladies et ravageurs et minimiser leur impact sur le rendement tout en fournissant d'autres services écosystémiques. J'ai cherché à comprendre comment la diversification des systèmes conventionnels à base de caféiers en systèmes agroforestier influence les pertes de rendement dues aux maladies et ravageurs. Je me suis interrogée sur comment prendre en compte les compromis induis par la présence d'arbres d'ombrages dans les systèmes étudiés, et cela à différentes échelles. Et j'ai cherché à révéler quelles voies d'actions sous-tendent le service de régulation des maladies et ravageurs au sein du système et à caractériser l'effet de la diversité des arbres d'ombrages sur les processus de régulation des maladies et ravageurs. Je propose maintenant de faire évoluer mon projet de recherche afin de mieux répondre aux enjeux de résilience des systèmes de cultures face aux changements globaux en 1) intégrant de nouvelles espèces cultivées pérennes dans les systèmes agroforestiers (cacaoyers et bananiers) et étudier les opportunités que cela offre en terme de durabilité pour les producteurs ; 2) passer d'une approche " pathogène centrée " à une approche " santé centrée " et prendre en compte les déterminants de la santé des plantes pour concevoir des systèmes résilients au maladies et ravageurs; 3) prendre en compte et quantifier les disservices écosystémiques dans l'évaluation des systèmes pour appuyer l'aide à la décision et l'accompagnement dans le changement de pratiques vers l'agroécologie
Regulator experiences of trials during Ebola epidemics in Sierra Leone, Guinea, and the Democratic Republic of the Congo
Get PDFIntroduction: During the 2014–2016 Ebola epidemic in West Africa and the Ebola outbreaks between 2018 and 2020 in the Democratic Republic of Congo, vaccines and other tools for prevention and treatment had to be taken through trials in exceptional circumstances using accelerated processes. Materials and methods: We interviewed members of ethics committees, health authorities, health professionals, and political authorities in the Democratic Republic of Congo in 2021 and held a workshop with ethics committee members and regulatory authorities from Sierra Leone and Guinea in 2022 in order to document their experiences of reviewing, approving, and regulating current and new studies during epidemics and outbreaks, and to document lessons learnt and their recommendations for the rapid review of clinical trial protocols during public health emergencies. Results: Similar barriers were identified in the three countries. These were related to weak legal frameworks and partnerships between ethics committees and regulatory bodies. Inadequate human resources, outdated standard operating procedures and guidelines, and lack of finance to support timely reviews were identified. We also noted a lack of awareness from politicians, scientists, and communities about the existence and functions of regulatory bodies/ethics committees, a lack of independence, and low interest in research. Opportunities identified by the institutions in the countries concerned included training ethics committee members and networking with experienced international platforms like the African Vaccine Regulatory Forum. Laws on regulating research have been updated in Sierra Leone and in Guinea, but not yet in the Democratic Republic of Congo. Conclusion: Regulatory bodies have been facing many challenges in terms of a lack of a legal framework, a lack of finance, and a lack of support from politicians, scientists, and communities. Networking has been an opportunity for these regulators to mitigate these impediments
Obtaining biological reagents for the development of a diagnostic method for leaf scald in sugar cane
No full textInteracting and dynamic effects of species and structural diversity promote annual woody biomass production in a tropical tree diversity experiment
Get PDFDifferent aspects of diversity, such as species richness and structural diversity, have been shown to enhance forest ecosystem functions, including biomass production. However, whether diversity-productivity relationships change over time or with climatic conditions remains uncertain. We analyzed above-ground woody biomass increment (AWBI) derived from annual inventory data and micro-densitometry on stem disks from 'Sardinilla' in Panama, one of the oldest tropical tree diversity experiments. We investigated AWBI in five tree species growing in monospecific and species-rich neighborhoods. We hypothesized that a) species and structural diversity would increase AWBI, with these effects strengthening over time, b) species diversity effects on AWBI would be mediated by structural diversity, and c) overyielding in diverse neighborhoods would persist under drought. We observed higher AWBI in species-rich compared to monospecific neighborhoods despite slightly decreasing wood density. The strong complementarity effects in mixtures increased over time, indicating progressive strengthening of diversity effects. Species diversity strongly effected AWBI by directly enhancing productivity and indirectly, via increasing structural diversity. Structural diversity had a direct positive effect on AWBI, but this effect weakened with tree age. Overyielding in species-rich neighborhoods persisted or even increased under extremely dry conditions likely due to complementary water use among species. Our results corroborate that mixed planted forests are more productive and have a greater ability to maintain their performance under stressful conditions compared to monocultures. Forest management aiming at maximizing carbon sequestration in plantations should include fast-growing species with high wood density and promote not only tree species richness but also structural diversity
Functional recovery of tropical forests: The role of restoration methods and environmental conditions
Get PDFForest and landscape restoration strategies influence the recovery of plant functional traits, which in turn shape ecosystem processes. To understand how traits respond to restoration and environmental conditions, we assessed the functional recovery of three forest restoration types in Brazil's Atlantic Forest: natural regeneration, high-diversity restoration plantations (20–60 species), and unmanaged tree monocultures. Across 285 plots aged 1–76 years, we quantified seven leaf and stem traits for over 500 species. For each plot, we calculated community mean trait values and three functional diversity indices. The three restoration types showed contrasting successional patterns. Natural regeneration and restoration plantations shifted from acquisitive to conservative resource-use strategies with site age, while monocultures moved in the opposite direction. Restoration plantations exhibited the highest functional richness. Soil conditions (sand content and sum of bases) influenced trait composition and diversity, whereas climate and landscape context had smaller effects. In 20-year old sites, most traits in natural regeneration and restoration plantations approached 90 % of forest remnants values. In contrast, unmanaged monocultures recovered slowly, with only half of the traits reaching this threshold in 40-year old sites. Our findings show that restoration methods and site conditions jointly shape functional recovery. Natural regeneration tends to align with forest remnant traits, restoration plantations speed up early recovery but may diverge over time, and monocultures require active interventions to enhance outcomes. Recognizing these functional trajectories is key to improving biodiversity conservation and ecosystem resilience in tropical forest restoration
Compte-rendu de mission : 5ème séminaire de l'écosystème Recherche Data Gouv, 16-18 juin 2025 à Lille sur données, codes et logiciels
No full textLe 5ème séminaire de l'écosystème Recherche Data Gouv, qui s'est tenu trois ans après son lancement, a été illustré la vitalité et la croissance continue de cet écosystème. Pendant deux jours, les participant.e.s ont pu échanger intensément autour des enjeux liés aux données de recherche, codes et logiciels