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Physicochemical, Sensory and Antioxidant Properties of Biscuit Fortified with Carica papaya, Ananas comosus and Beta vulgaris Mixed Powder
No full textInternational audienceBackground and Aims: Beetroot, papaya and pineapple constitute important natural ingredients in producing functional foods due to the presence of bioactive and antioxidant compounds. Therefore, this study aimed to formulate and evaluate the physicochemical composition and antioxidant properties of biscuits fortified with papaya, pineapple and beetroot mixed powder at the rates of 10%, 15%, 20% and 25% (w/w). Methods: The hardness, pH, water absorption capacity, nutritional content and in vitro antioxidant profile were analysed using standard methods. Sensory analysis parameters were determined using 9-level hedonic scale. Results: The hardness varied from 92.02 ± 4.29 to 104.66 ± 2.98 N for biscuits with 25% and 10% of fruit powder respectively. pH values decreased significantly with fruit powder addition in biscuits. The use of beetroot, pineapple and papaya powder resulted in a slight increase in water absorption capacity (33.32-160.53%). Moisture, fat, protein, fiber, ash, soluble sugars and carbohydrate content ranged from 4.79-9.92%, 17.02-21.65g/100g, 7.94 -9.89g/100g, 2.46-14.86g/100g, 2.39-3.55g/100g, 42.14-56.85g/100g, 5.29-8.69g/100g respectively. The micronutrients Fe, Zn, Mg and Vitamin C ranged from 4.28-8.39%, 4.82-5.74%, 20.41-62.31% and 41.44-84.68% respectively. The antioxidant profiling showed a similar increase in ferric reducing antioxidant power (FRAP) (0.91-3.36µmol.100g-1) total flavonoids (158.75-861.25 mg. QE 100g-1), total phenolic (203.75-562.65 mg GAE.100g-1), 2,2-Diphenyl-1-PicrylHydrazyl (DPPH) free radical scavenging activities (20.83-69.71 %) and anti-radical activity (42.59-94.34%). Among the different formulations, the biscuits prepared with 10% of fruit powder (PAB10) had the highest sensory quality with an overall acceptability score of 6.71. While the biscuit with the best nutritional potential was the biscuit fortified with 25% of fruit powder. This study highlights the potential of utilizing papaya, pineapple and beetroot in functional biscuits, hence it can serve as relief for malnutrition
Évaluation économétrique de la relation croissance économique - développement durable en République démocratique du Congo
No full textInternational audienceAbstract This paper addresses the issue of economic growth from a sustainable development perspective. Through appropriate econometric modeling, it relates the different dimensions of sustainable development and their effects on economic growth in the Democratic Republic of Congo (DRC). Data estimation using the Ordinary Least Square method is corrected by the Vector Error Correction Model (VECM). Correction Model"). The results show that, in the long term, the HDI and CO2 emissions have a fairly significant influence on economic growth in the DRC over the study period. If the HDI varies by 1-point, economic growth in the DRC increases by 3.261384%, while an increase in economic growth of 7.8 points leads to an increase in CO2 pollution of 1 point. Any long-term increase in production leads to an increase in CO2 emissions. There is therefore a negative influence between the economic dimension of sustainable development and the environmental dimension. Also, any long-term increase in GDP leads, all other things being equal, to an increase in the HDI, i.e. a positive change in the population's standard of living. This result shows that there is a positive influence between the social dimension of sustainable development and the economic dimension. The Congolese government therefore needs to implement an expansionist structural economic policy with a focus on environmental protection, in order to minimize the negative effects of economic growth in terms of social inequality and increased atmospheric pollution.Résumé Ce papier aborde la question de croissance économique dans une perspective du développement durable. A travers une modélisation économétrique appropriée, il met en relation les différentes dimensions du développement durable et leurs effets sur la croissance économique de la République démocratique du Congo (RDC). L’estimation des données par la méthode de Moindre Carré Ordinaire est corrigée par le Modèle Vectoriel à Correction d’Erreur (VECM, « Vector Error Correction Model »). Les résultats renseignent qu’à long terme l’IDH et l’émission de CO2 ont une influence assez significative sur la croissance économique de la RDC pendant la période sous étude. Si l’IDH varie de 1 point, la croissance économique de la RDC augmente de 3,261384% alors que l’augmentation de la croissance économique de 7,8 points entraine une augmentation de la pollution de CO2 de 1 point. Toute augmentation à long terme de la production entraine une augmentation des émissions de CO2. Il y a donc une influence négative entre la dimension économique du développement durable et la dimension environnementale. Aussi, toute augmentation du PIB à long terme entraine toute chose restant égale par ailleurs, l’augmentation de l’IDH soit une modification positive du niveau de vie de la population. De ce résultat, on dégage l’existence d’une influence positive entre la dimension sociale du développement durable et la dimension économique. Ainsi, Le gouvernement congolais devra donc mettre en place une politique économique structurelle expansionniste mettant l’accent sur la protection de l’environnement afin de minimiser les retombées négatives de la croissance économique qui se traduisent par des inégalités sociales et l’accentuation de la pollution de l’atmosphère
A new global high-resolution wave model for the tropical ocean using WAVEWATCH III version 7.14
No full textInternational audienceClimate change is driving sea-level rise and potentially intensifying extreme events in the tropical belt, thereby increasing coastal hazards. On tropical islands, extreme sea levels and subsequent marine flooding can be triggered by cyclones but also distant-source swells. Knowledge of sea states in the tropical ocean is thus of key importance, and their study is usually based on spectral wave models. However, existing global wave models typically employ regular grids with a coarse resolution, which fail to accurately represent volcanic archipelagos, a problem usually circumvented by the use of obstruction grids but typically resulting in large negative biases. To overcome this problem, this study presents a new global wave model with a focus on distant-source swells, which have received less attention than waves generated by cyclones. To accurately simulate sea states in tropical areas, we implemented the spectral wave model WAVEWATCH III© (WW3) over a global unstructured grid with a spatial resolution ranging from 50 km to 100 m. The model is forced by ERA5 wind fields, corrected for negative biases through a quantile–quantile approach based on satellite radiometer data. The wind input source terms adjusted accordingly and the explicit representation of tropical islands result in improved predictive skills in the tropical ocean. Moreover, this new simulation allows for the first time direct comparisons with the in situ data collected on volcanic islands at water depths ranging from 10 to 30 m, which corresponds to a few hundred meters from the shore
Le rôle des populations autochtones riveraines et des communautés locales dans la réduction de la criminalité faunique en République Démocratique du Congo
No full textLes populations autochtones riveraines et les communautés locales jouent un rôle crucial dans la réduction de la criminalité faunique en République Démocratique du Congo (RDC). En raison de leur proximité avec les écosystèmes et de leur connaissance approfondie de la faune, elles sont des acteurs clés dans la surveillance et la protection des espèces menacées. Leur implication passe par des initiatives de sensibilisation, le développement d'alternatives économiques durables implique la dépendance au braconnage, ainsi que la collaboration avec les autorités et les organisations de conservation pour signaler les activités illégales. Cependant, leur contribution reste entravée par le manque de moyens, l'absence de reconnaissance légale suffisante et les pressions économiques. Renforcer leur engagement par des programmes de formation, un appui financier et une meilleure intégration dans les politiques de gestion de la biodiversité est essentiel pour lutter efficacement contre la criminalité
Emergence and spread of the SARS-CoV-2 omicron (BA.1) variant across Africa: an observational study
No full textInternational audienceBackground: In mid-November, 2021, the SARS-CoV-2 omicron variant (B.1.1.529; BA.1 sublineage) was detected in southern Africa, prompting international travel restrictions. We aimed to investigate the spread of omicron BA.1 in Africa.Methods: In this observational study, samples from patients infected with SARS-CoV-2 from 27 laboratories in 24 African countries, collected between June 1, 2021 and April 14, 2022, were tested for omicron BA.1 and delta (B.1.617.2) variants using real-time RT-PCR. Samples that tested positive for BA.1 by RT-PCR and were collected before estimated BA.1 emergence according to epidemiological properties were excluded from downstream analyses. The diagnostic precision of the assays was evaluated by high-throughput sequencing of samples from four countries. The observed spread of BA.1 was compared with mobility-based mathematical simulations and entries for SARS-CoV-2 in the Global Initiative on Sharing All Influenza Data (GISAID) genomic database. We estimated the effective reproduction number (Rt) at the country level considering the BA.1 fraction and the reported numbers of infections. Phylogeographical analyses were done in a Bayesian framework.Findings: Through testing of 13 294 samples from patients infected with SARS-CoV-2, we established that, by November-December, 2021, omicron BA.1 had replaced the delta variant of SARS-CoV-2 in all African subregions, following a south-north gradient, with a median Rt of 2·60 (95% CI 2·46-2·71). This south-north spread, established on the basis of PCR data, was substantiated by phylogeographical reconstructions, ancestral state reconstructions, and GISAID data. PCR-based reconstructions of country-level BA.1 predominance and the availability of BA.1 genomic sequences in GISAID correlated significantly in time (p=0·0002, r=0·78). The first detections of BA.1 in high-income settings beyond Africa were predicted accurately in time by mobility-based mathematical simulations (p<0·0001). Comparing PCR-based reconstructions with mobility-based mathematical simulations suggested that SARS-CoV-2 infections in Africa were under-reported by approximately ten times. Inbound travellers infected with BA.1, departing from five continents, were identified in six African countries by early December, 2021.Interpretation: Omicron BA.1 was widespread in Africa when travel bans were implemented, limiting their effectiveness. Combined with genomic surveillance and mobility-based mathematical modelling, PCR-based strategies can inform Rt and the geographical spread of emerging pathogens in a cost-effective and timely manner, and can guide evidence-based, non-pharmaceutical interventions such as travel restrictions or physical distancing
Prévision énergétique en milieu tropical insulaire : une taxonomie opérationnelle pour une précision robuste à faible coût computationnel
No full textTropical island territories like Reunion face significant reliance on fossil fuels and vulnerability to extreme climate events. Accurate energy forecasting—both consumption and renewable generation—is crucial to enhance grid stability and support a sustainable energy transition. Traditional methods, such as deterministic physical models, struggle to capture complex tropical climate dynamics, while purely data-driven models are computationally intensive and heavily dependent on extensive data, which is often incomplete in island contexts.This paper proposes a novel hybrid approach structured in three complementary layers: (1) a physical model based on thermodynamic principles tailored to tropical climates; (2) a statistical layer employing models like ARIMA, SARIMA, GARCH, and SARIMAX to handle trends, seasonal effects, and volatility; and (3) an optimized neural layer (compressed LSTM networks) to capture residual nonlinear dynamics. Techniques like pruning, quantization, and federated learning further reduce computational demands and energy usage.Applied to real-world data from five university buildings in La Réunion, this hybrid method demonstrated significantly improved forecasting precision with minimized computational costs. The results showed a 30% accuracy improvement during extreme weather events and a 45% reduction in computational requirements compared to traditional approaches.Future work includes automated model recalibration, further optimization for managing peak loads during climatic extremes, and broader deployment across island microgrids. Ultimately, this approach offers a practical, computationally efficient solution for enhancing renewable energy integration and resilience in tropical island settings.Les territoires insulaires tropicaux, tels que La Réunion, affrontent une forte dépendance aux énergies fossiles et une vulnérabilité aux aléas climatiques extrêmes. Dans ce contexte, la prévision énergétiquecouvrant à la fois la consommation des bâtiments et la production renouvelable -s'avère cruciale pour assurer la stabilité du réseau et soutenir la transition vers un mix énergétique plus durable. Les approches classiques (modèles physiques déterministes ou modèles purement data-driven) montrent néanmoins leurs limites : les premières peinent à intégrer la complexité des phénomènes climatiques tropicaux (humidité, cyclones, îlots de chaleur), tandis que les secondes souffrent d'une dépendance importante à de grands volumes de données et présentent des coûts computationnels élevés.Cet article propose une architecture hybride structurant la prévision énergétique en trois couches : (1) un modèle physique fondé sur les bilans énergétiques et les principes thermodynamiques spécifiques aux milieux tropicaux ; (2) une couche statistique (ARIMA, SARIMA, GARCH, SARIMAX) dédiée à la capture des tendances, des effets saisonniers et de la volatilité conditionnelle ; et (3) une couche neuronale (LSTM optimisé) pour modéliser les non-linéarités résiduelles. Des stratégies de compression (pruning, quantification) et d'apprentissage fédéré sont intégrées afin de réduire la consommation énergétique et faciliter le déploiement dans des contextes insulaires contraints.Cette approche hybride améliore la précision des prévisions tout en minimisant l'empreinte computationnelle, contribuant ainsi à une meilleure intégration des énergies renouvelables et à un pilotage résilient des micro-réseaux. Les perspectives incluent une automatisation renforcée du recalibrage, la réduction des pics de charge lors d'événements climatiques extrêmes et l'optimisation à long terme de la planification énergétique pour les territoires tropicaux insulaires.</div
High Stress Drop and Slow Rupture During the 2020 M<sub>W</sub>6.4 Intraplate Petrinja Earthquake, Croatia
No full textInternational audienceHere we analyze the rupture process of the 29 December 2020 M W 6.4 Petrinja earthquake (Croatia), the largest event instrumentally recorded in this area characterized by a moderate strain-rate intraplate setting. We use foreshocks and aftershocks, recorded at more than 80 broadband stations located 70-420 km from the earthquake, as empirical Green's functions (EGFs) to separate source effects from propagation and local site effects. First, we deconvolve the mainshock P-wave time windows from the EGFs in the frequency domain to obtain the corner frequency ( f c ). Spectral analysis based on the Brune's source model reveals a large stress drop of 24 MPa. Next, by deconvolving the Love waves in the time domain, we calculate the Apparent Source Time Functions (ASTFs). We find that the average duration of the source is ∼5 s, with no significant directivity effects, indicating a bilateral rupture. To extract physical rupture parameters such as rupture velocity, slip distribution and rise time, we deploy two techniques: (a) Bayesian inversion and (b) backprojection onto isochrones of ASTFs. Both techniques show a low rupture velocity (40%-50% of the shear wave velocity) and a rupture length of less than 10 km, that is, much less than would typically be expected for a magnitude 6.4 earthquake. This apparent anticorrelation between stress drop and rupture velocity may be attributed to the complex and segmented fault system characteristic of immature intraplate settings
E-mail overload: Exploring employees' experiences using e-mail during worktime and leisure time and consequences for their subjective well-being
No full textInternational audienceIncreased connectivity between employees and their organizations complicates managing information flows and constant availability via e-mail. We classify employees' e-mail experiences using e-mail into groups of e-mail overload based on a boundary perspective and assess its impact and coping mechanisms, from a coping perspective, on subjective well-being. Survey results (N = 1,372) show that (1) e-mail overload during worktime increases job stress and reduces job and life satisfaction; (2) e-mail overload during work and leisure increases job stress and reduces life satisfaction; and (3) having no e-mail overload decreases job stress and improves job and life satisfaction. We formulate implications for research and practice
Sphagnum peatlands of Reunion Island: potential and limitations as environmental archives for the Quaternary of the Indian Ocean.
No full textInternational audienceContrary to temperate and boreal peatlands built after the glacial retreat, tropical peatlands are potentially recording environmental information pre-dating the Holocene. However on tropical volcanic islands, Sphagnum moss are scarce and/or rarely build peat.Within the framework of the several projects on the territory of Reunion Island, we sampled peat bogs and Sphagnum mats of Reunion Island in 2021 (Margenat and Le Roux, 2023). The objectives were originally to use them as microplastic traps and thus reveal the history of atmospheric contamination by microplastics in the Indian Ocean over the last fifty years. It turns out some peat cores are older than expected and can provide amazing archives for the Holocene and Last Glacial environmental history of the Indian Ocean and La Réunion Island itself including the last period of strong volcanic activities. For example, one site located in the heart of the National Park is 25 ky old.In this talk, we will present the diversity of the Sphagnum peatlands of La Réunion, the first results of peat characterization, and the first results of radiometric age dating covering the last glacial maximum, the Holocene, and the most recent periods. We will then discuss potential and limitations of La Réunion peat records in paleo-landscape, paleo-atmosphere and carbon cycle aspects. References:Margenat, H., Le Roux, G., 2023. POST EXPEDITION REPORT Field Expedition La Réunion Island, France ATMO-PLASTIC Project. Zenodo. https://doi.org/10.5281/zenodo.764359
Adaptation et Validation Française de L’échelle de Mesure des Croyances Conspirationnistes Liées aux Epidémies
No full textInternational audienceL’échelle de mesure générique des croyances conspirationnistes permet d’appréhender les croyances conspirationnistes en général, mais ne permet pas de mesurer les croyances conspirationnistes spécifiques aux épidémies. Le présent article a pour objectif d’adapter et de valider une version française de la mesure des croyances conspirationnistes spécifiques aux épidémies, issue de la Generic Conspiracist Beliefs Scale (GCBS, Brotherton et al., 2013). Les données sont recueillies par questionnaire auprès de la population générale francophone (N = 1630), pendant la pandémie de la Covid-19, en utilisant 6 items issus de la GCBS en lien avec les épidémies. Une analyse factorielle exploratoire et confirmatoire réalisée sur deux sous-échantillons indépendants fait ressortir une structure unidimensionnelle de l’échelle, avec des indices de validité convergente et discriminante satisfaisants. En outre, les croyances conspirationnistes prédisent négativement l’efficacité perçue des mesures de prévention; ce qui confirme la validité prédictive de l’échelle. On discute de son intérêt et de son utilité pour le diagnostic des croyances conspirationnistes en temps de pandémie, comme celle de la Covid-19