122418 research outputs found
Sort by
Why participatory plant research now?
Get PDFIn the current polycrisis era, plant science, particularly when applied to agronomy, becomes instrumental: because our main substantial and renewable resource is plant biomass, many future solutions will depend on our ability to grow and transform plant material in a sustainable way. This also questions the way we conduct plant research and thus quantitative plant biology. In response to the increasing polarization between science and society, participatory plant research offers a pertinent framework. Far from moving away from quantitative approaches, participatory plant research builds on complexity associated with biology and situated knowledge. When researchers and citizens work together on societal issues, such friction becomes more fertile, quantitative questions become more complex, societal issues are addressed at their roots and outcomes often exceed that of top-down strategies. This article serves as an introduction to this ongoing bifurcation in plant science, using plant breeding as a key example
Threshold-dependent improvement in sex separation efficiency by NaCl pretreatment of larval-pupal mixtures in mass-reared Aedes albopictus
No full textBACKGROUND: The removal of female mosquitoes is a critical requirement in sterile insect technique (SIT) for mosquito control. Improving the efficiency and accuracy of sex sorting is therefore vital. Previous studies have demonstrated that treating larval–pupal mixtures with a 15% sodium chloride (NaCl) solution prior to the sex sorting process reduces female contamination in Aedes mosquitoes. However, the effects of NaCl on Aedes albopictus mosquito biology and its practical application in production facilities remain insufficiently explored and warrant further investigation. RESULTS: Exposure of larval–pupal mixtures to 15% NaCl for 60 min led to 100% larval mortality via osmotic imbalance and intestinal tissue damage, while pupae remained unaffected due to their impermeable cuticle. Males emerging from treated pupae exhibited comparable emergence, longevity, and flight ability to controls, indicating no adverse effect on male quality. NaCl pretreatment significantly improved sorting efficiency and reduced female contamination in manual sorting, achieving a 3.9-fold reduction in adult-stage contamination. Although automatic sorters increased throughput, reductions in female contamination were not statistically significant. Importantly, the sorting benefits of NaCl treatment were threshold-dependent and most evident at larger processing scales. CONCLUSION: NaCl pretreatment is a simple, scalable, and biologically safe strategy to enhance sex separation in Ae. albopictus mass production. It is particularly advantageous under high-throughput conditions and preserves male fitness, supporting the stringent quality standards required for successful SIT-based mosquito control. © 2025 Society of Chemical Industry
Bilan des activités de restauration forestière à Dzeng et à Mindourou, Centre et Est Cameroun
Get PDFLe présent rapport s'inscrit dans le cadre du projet PROFEAAC, qui vise à légaliser et formaliser l'exploitation artisanale du bois en Afrique centrale, tout en faisant la promotion de la restauration forestière. Le projet PROFEAAC comporte plusieurs composantes, dont la composante 2, qui concerne cette étude sur la mise en place de mesures locales de régénération et de reboisement. Ce rapport établit un bilan des activités de restauration forestière dans deux communes camerounaises : Dzeng (Centre) et Mindourou (Est). D'après la littérature, les facteurs moteurs de la déforestation dans ces régions sont : 1) les pratiques agricoles (défriche-brûlis, plantations de cacao et de cultures vivrières), 2) l'exploitation artisanale du bois d'oeuvre, qui reste largement informelle et non régulée, 3) la pression démographique croissante et l'urbanisation, surtout à Dzeng, qui stimulent la demande en bois et produits agricoles. L'étude repose sur plusieurs approches : 1) l'analyse des données de suivi des plantations effectuées par les bénéficiaires du projet, 2) le diagnostic agraire pour caractériser les pratiques agricoles locales et leurs évolutions, 3) l'analyses statistiques pour mesurer l'impact du projet sur la survie des arbres plantés. Le travail de terrain s'est déroulé sur deux semaines par terrain, complété par des études antérieures du projet PROFEAAC et d'autres initiatives similaires. Les principaux résultats sur les plantations peuvent être résumés ainsi : • A Dzeng, 30 bénéficiaires ont planté 1327 arbres (44,4 arbres/planteur). • A Mindourou : 67 bénéficiaires ont planté 1467 arbres (21,9 arbres/planteur). Le taux de survie à 12 mois : 48,6 %, avec une meilleure performance pour les arbres fruitiers (54,2 %) que les essences locales (45,8 %). A propos des dynamiques agricoles et foncières, le constat est le suivant : 1) La région est marquée par une déforestation accélérée, notamment due à (i) le souhait d'acquisition de droits fonciers par le " droit de hâche ", (ii) l'expansion des cultures du cacao et du manioc, 2) les terres sont gérées coutumièrement, avec une transmission patriarcale des droits fonciers, 3) les élites urbaines investissent de plus en plus dans des terres agricoles, ce qui stimule la conversion des forêts en plantations, notamment à Dzeng. Quatre systèmes de culture dominent : 1) la défriche forestière (SC1) : Association bananier-plantain et cultures vivrières sur terrains nouvellement défrichés, notamment pour l'acquisition foncière, 2) les cultures Vivrières sur friches (SC2): cultures de manioc, macabo, arachide et maïs sur des friches de 4 à 6 ans, 3) les cacaoyères (SC3) sont en plein essor, avec intégration de fruitiers et d'essences locales pour créer un système agroforestier, 4) Les bananeraies permanentes: Gestion durable des parcelles de bananiers. Compte tenu de la déforestation et la dégradation forestière, dans ces deux communes soumises aux défrichements agricoles et pour l'acquisition de droits fonciers, la restauration forestière peut avoir seulement un impact limité. Néanmoins, le projet PROFEAAC a su, en réorientant son appui, profiter de l'opportunité que représente le développement du cacao et des cultures fruitières dans ces localités afin d'encourager les planteurs à enrichir leurs cacaoyères en arbres fruitiers. Ce faisant le projet a pu s'ancrer dans le développement de la filière de cacao agroforestier camerounaise. On notera néanmoins que l'approche agricole du territoire et de ses dynamiques en cours semble plus adaptée et pertinente pour construire un projet de gestion durable d'un territoire qu'une approche purement forestière. En effet, il semble nécessaire de mieux accompagner les agriculteurs sur le long terme dans l'ensemble de leurs activités, y compris agroforestières
Functional characterization and differentiated harmfulness of sugarcane weeds
No full textWeed-related yield losses are challenging to measure and predict but are estimated to be up to 34% in temperate environments and over 50% in tropical regions. Weed impact depends on their abundance but also on their trophic resource acquisition strategies. This study aims to: (i) assess the response of sugarcane yield to different weed communities shaped by three weed-management strategies, (ii) classify weed species as a function resource competition strategy (defined from their functional traits), and (iii) link these strategies to their effects on sugarcane yields. We performed two controlled sugarcane field trials in La Réunion island from 2021 to 2023. In these trials, we artificially created different weed communities using weed control interventions (chemical and manual), and then measured the sugarcane growth obtained on these plots. We also measured various aboveground and root functional traits linked to competition for light and soil resources on major weed species. Linear mixed models were used to assess the effects of treatments on biomass and cane yield components, and a Principal Component Analysis followed by hierarchical classification were used to group species according to their traits. Finally, an RLQ and fourth-corner analysis explored the links between weed traits, species and sugarcane yield components. Sugar cane growth was significantly influenced by the weed communities in both trials. The impact of weed cover was clearly visible, but some differences could be attributed to the weed resource acquisition strategies. Creepers were mostly associated with acquisitive aboveground strategies and conservative belowground ones. Some dicotyledonous weeds were more likely to be associated with conservative aboveground strategies level and acquisitive belowground ones. However, these strategies did not have the same impact on the sugarcane growth depending environmental conditions. Under optimal fertilization and irrigation, sugarcane growth was mainly reduced by weeds with acquisitive aboveground strategies (i.e. creepers), while without fertilization and irrigation, sugarcane biomass was mostly decreased by weeds with belowground acquisitive strategies. This study illustrates the complexity of weed harmfulness, which varies significantly depending on the composition and characteristics of weed species, particularly their resource acquisition strategies, as well as their interactions with environmental conditions
Continuous monitoring of fire-induced forest loss using Sentinel-1 SAR Time Series and a Bayesian method: A case study in Paragominas, Brazil
Get PDFForest fires, intensified by climate change, threaten tropical ecosystems by accelerating biodiversity loss, releasing carbon emissions, and altering hydrological cycles. Continuous detection of fire-induced forest loss is therefore critical. However, commonly used optical- based methods often face limitations, particularly due to cloud cover and coarse spatial resolution. This study explores the use of C-band Sentinel-1 Synthetic Aperture Radar (SAR) time series, combined with Bayesian Online Changepoint Detection (BOCD), for detecting and continuously monitoring fire-induced vegetation loss in forested areas. Three BOCD variants are evaluated: two single-polarization approaches individually using VV and VH reflectivities, and a dual-polarization approach (pol-BOCD) integrating both channels. The analysis focuses on a fire-affected area in Baixo Uraim (Paragominas, Brazil), supported by field-validated reference data. BOCD performance is compared against widely used optical products, including MODIS and VIIRS active fire and burned area data, as well as Sentinel-2-based difference Normalized Burn Ratio (dNBR) assessments. Results indicate that pol-BOCD achieves spatial accuracy comparable to dNBR (88.2% agreement), while enabling detections within a delay of three Sentinel-1 acquisitions. These findings highlight the potential of SAR-based BOCD for rapid, cloud-independent monitoring. While SAR enables continuous detection regardless of atmospheric conditions, optical imagery remains essential for characterizing the type and severity of change
Can agrodealers be agents of sustainability transitions in agriculture? Reflections based on the expansion of biological inputs in Mexico
Get PDFAgrodealers are key players in providing technologies and support services to farmers. Nevertheless, they are generally perceived as reluctant, or at least inactive, in the transition to more sustainable practices. In this article, we examine their contribution to the expansion of biological inputs - biological control, biofertilizers, bio-stimulants - understood as a set of alternative technologies for reducing the consumption of chemical inputs. Based on a qualitative survey of agrodealers and various agricultural R&D stakeholders in Mexico's Bajío grain-production region, we show that they play a proactive role in the expansion of these technologies. Faced with a highly competitive environment, including these products in their portfolio enables them to differentiate themselves from their competitors, while continuing to promote the productivity and profitability of their crops to their customers. In some cases, they not only distribute the products of upstream industries, but also become producers themselves of the microorganisms they offer for sale. They are also actively involved in encouraging farmers to acquire and use these technologies, while striving to minimize the disruption that this may cause to their practices. To this end, they provide advice and support, and develop formulas for integrating biological inputs into technical packages that facilitate their adoption. These results call for a reconsideration of the role these actors could play in initiatives aimed at promoting sustainable technologies and practices for the agricultural sector
Prevalence estimates and nature of online child sexual exploitation and abuse: A systematic review and meta-analysis
No full textBackground: Online child sexual exploitation and abuse (OCSEA) is a global health issue. The aim of this global systematic review and meta-analysis was to better understand the prevalence and nature of OCSEA on a global scale. Methods: Comprehensive literature searches were done in six UN languages (Arabic, Chinese, English, French, Russian, and Spanish) and multiple databases, for records published between Jan 1, 2010, and Sept 30, 2023. Studies were evaluated independently by two different authors for inclusion according to eligibility criteria. Eligible studies included children younger than 18 years or adults retrospectively reporting OCSEA. Studies used general population samples and were representative at the national and sub-national level. Risk of bias in prevalence studies was assessed and a synthesis of the findings produced. A random-effects model was conducted for meta-analysis of studies to calculate prevalence estimates with 95% CIs for past year recall and lifetime recall of four OCSEA subtypes and overall OCSEA (from studies that measured at least three different sub-types within the same sample). This study was pre-registered with Open Science Framework (osf.io/6vux2). Findings: Of the 47 097 records derived from literature searches, 86 records reporting on 123 studies were included in this systematic review and meta-analysis. Pooled mean prevalence for past year recall of OCSEA subtypes was estimated: online solicitation (12·5% [95% CI 10·5–14·7]); non-consensual taking, sharing, and exposure to sexual images and videos (12·6% [9·7–16·2]); online sexual exploitation (4·7% [2·9–7·3]); and sexual extortion (3·5% [1·9–6·4]). The mean prevalence of past-year recall for overall OCSEA was 8·1% (4·9–13·0). Heterogeneity of individual estimates was high, influenced by research design factors including the method of data collection and variability in definitions used. Interpretation: Heterogeneity in prevalence estimates identified across studies and regions indicates that more research is required to draw stronger conclusions about the scale of OCSEA. However, the findings of this study are of great relevance to policy makers, practitioners, and researchers to make informed decisions about allocating resources and designing effective prevention and response programmes to protect children worldwide
Gardeners' knowledge, practices and associated risk factors for multidrug-resistant bacteria dissemination in environment and humans: A One Health approach in gardens of Ouagadougou, Burkina Faso
Get PDFBackground: Garden products can be contaminated with multidrug-resistant (MDR) bacteria through fecal waste, irrigation water, biosolids, or animal manure used as fertilizer. This study assesses the knowledge and practices of gardeners in Ouagadougou, and identifies risk factors for MDR bacteria spread in humans and the environment using a One Health approach. Methods: In April 2023, a questionnaire survey was conducted among 110 consenting gardeners from three sites (Paspanga, Tanghin, and Boulmiougou). Data were collected via face-to-face interviews using Kobo Collect and analyzed using descriptive statistics and logistic regression to identify factors linked to low knowledge and risk. Results: Most participants were male (52.7%), 70.9% had no formal education, and 54.6% were aged 41–60 years. The majority used well water for irrigation (99.1%). All used organic fertilizers, but 92.7% did not produce their own, and composting was low (23.6%). Shared latrines were used by 71.8%, and 60.0% did not use personal protective equipment. Knowledge gaps were significant: 72.7% didn't believe irrigation water could contaminate produce, 73.6% were unaware of manure risks, and 67.3% didn't think contaminated produce could infect humans. Logistic regression revealed that perceptions about water contamination were paradoxically linked to higher odds of risky behaviour (odds ratio = 3.48, p = 0.016). Conclusion: This study reveals knowledge gaps and risky practices among gardeners, contributing to MDR bacteria spread and posing health risks. Urgent interventions are needed to improve education, infrastructure, and practices in urban farming
