Violence and the Wandering Motif in Ahmadou Kourouma’s Allah n’est pas obligé and Alex la Guma’s A Walk in the Night

This article studies the impact of violence on characters’ wandering in Ahmadou Kourouma’s Allah n’est pas obligé and Alex la Guma’s A Walk in the Night. After passing in review scholars’ position on violence and journey in fiction, it analyses first how  in Allah n’est pas obligé,  an orphaned child searching for an aunt to take care of him  embarks on wanderings in war-torn countries and gets dehumanised in the process. It then examines how, in A Walk in the Night, apartheid leaves characters from both the black and the white races unsettled in their prison-like District Six. The differences observed  are only  superficial because, in the main, the two novels meet on the feeling of loss and the aspiration for change which violence instils on characters and which is expressed physically by the latter’s wanderings. Keywords: violence, war, journey, child soldier, apartheid, dehumanization

Effet de l’entreposage à l’état congelé sur la qualité de la sardine (Sardina pilchardus)

Pour une meilleure compréhension des effets du stockage à l’état congelé de la sardine (Sardina pilchardus), principale espèce de poissons pélagiques produite au Maroc, la présente étude s’est proposée d’évaluer les effets du stockage à différentes températures (- 18°C, - 25°C et - 30°C) durant 6 mois sur les paramètres organoleptiques et nutritionnels principalement les acides gras polyinsaturés de la famille des oméga 3 ( EPA et DHA) de la sardine congelée. Les résultats obtenus ont montré que l’utilisation de la glace pour refroidissement avant congélation a un effet positif sur la qualité sensorielle et chimique de la sardine après capture. La sardine congelée puis entreposée aux températures les plus basses (-30°C) a conservée de meilleurs propriétés sensorielles et nutritionnelles (oméga 3 : EPA-DHA). De même, la sardine congelée conserve une meilleure qualité organoleptique et nutritionnelle lorsqu’elle est conservée entière. D’autres part, la corrélation de l’évolution des teneurs en ABVT avec l’altération organoleptique a permis de conclure que l’ABVT peut être utilisé comme indice fiable et objectif pour évaluer la qualité de la sardine congelée.Mots-clés: conservabilité, sardine, congélation, altération chimique, acides gras omega-3, EPA, DHA, ABVT et organoleptique. Effect of frozen storage on quality of sardine (Sardina pilchardus)For a better understanding of the effects of storage frozen sardine (Sardina pilchardus), the main species of pelagic fish produced in Morocco, this study is proposed to evaluate the effects of storage at different temperatures (- 18°C, - 25°C, - 30°C) for 6 months on the organoleptic and nutritional parameters mainly polyunsaturated fatty acids omega 3 (EPA and DHA) of frozen sardine. The results showed that the use of ice for cooling before freezing has a positive effect on the sensory and chemical quality of the sardine after capture. Frozen sardine stored at lower temperatures (-30 °C) was maintained better sensory and nutritional properties (omega 3 EPA - DHA). Similarly, frozen sardines retains better organoleptic and nutritional quality when stored whole. On the other hand, the correlation of changes in TVB-N with impaired sensory concluded that TVB can be used as reliable and objective index to evaluate the quality of frozen sardine.Keywords: conservability, sardine, freezing, chemical weathering, omega-3 fatty acids, EPA, DHA, TVB-N and organoleptic

Comprehensive comparison of airborne and spaceborne SAR and LiDAR estimates of forest structure in the tallest mangrove forest on earth

A recent suite of new global-scale satellite sensors and regional-scale airborne campaigns are providing a wealth of remote sensing data capable of dramatically advancing our current understanding of the spatial distribution of forest structure and carbon stocks. However, a baseline for forest stature and biomass estimates has yet to be established for the wide array of available remote sensing products. At present, it remains unclear how the estimates from these sensors compare to one another in terrestrial forests, with a clear dearth of studies in high carbon density mangrove ecosystems. In the tallest mangrove forest on Earth (Pongara National Park, Gabon), we leverage the data collected during the AfriSAR campaign to evaluate 17 state-of-the-art sensor data products across the full range of height and biomass known to exist globally in mangrove forest ecosystems, providing a much-needed baseline for sensor performance. Our major findings are: (Houghton, Hall, Goetz) height estimates are not consistent across products, with opposing trends in relative and absolute errors, highlighting the need for an adaptive approach to constraining height estimates (Panet al., 2011); radar height estimates had the lowest calibration error and bias, with further improvements using LiDAR fusion (Bonan, 2008); biomass variability and uncertainty strongly depends on forest stature, with variation across products increasing with canopy height, while relative biomass variation was highest in low-stature stands (Le Quereet al., 2017); a remote sensing product's sensitivity to variations in canopy structure is more important than the absolute accuracy of height estimates (Mitchardet al., 2014); locally-calibrated area-wide totals are more representative than generalized global biomass models for high-precision biomass estimates. The findings presented here provide critical baseline expectations for height and biomass predictions across the full range of mangrove forest stature, which can be directly applied to current (TanDEM-X, GEDI, ICESat-2) and future (NISAR, BIOMASS) global-scale forest monitoring missions

ESTIMATION ET SPATIALISATION DU STOCK DE BIOMASSE ET CARBONE AÉRIEN DES MANGROVES ESTUARIENNES AU GABON.

The mangroves of Gabon, from north to south, cover three coastal complexes: estuarine, deltaic and lagoon. The pure mangrove species found in these environments are Rhizophora racemosa, Rhizophora harrisonii, Rhi-zophora mangle, Avicennia germinans, Laguncularia racemosa and Conocarpus erectus. The study of the biomass and aerial carbon of these mangroves focuses only on those of the Komo, Mondah and Rio Mouni estuaries. Man-groves are one of the ecosystems that store the most biomass and carbon in the world. In a context of climate change, the estimates of biomass and carbon stock of mangroves are at the center of scientific concerns. Also, in this quest for quantification of biomass and carbon, Gabon has an important place. Indeed, its coastlines have the greatest specific richness of mangroves in the Central African sub-region and the highest mangroves on Earth. These par-ticularities of these mangroves give rise to the need for local biomass and carbon prediction tools. To address this concern, this study focuses on the estimation and spatialization of mangrove above-ground biomass and carbon. The tools of geog-raphy are used to spatially estimate and explain the mechanisms of biomass distribution in mangroves and estuaries. The present research resulted in the development of 14 models, including 10 ground-based prediction models: 5 vol-ume prediction models, 5 aboveground biomass prediction models, and 4 remote sensing prediction models (i.e. 3 mangrove height prediction models from SRTM and 1 aboveground biomass (AGB) and carbon prediction model from height). Salinity, pH, altitude, atmospheric pressure, pHmv, dissolved oxygen and temperature are factors in the location of Avicennia germinans. Spatial localization of Laguncularia racemosa, Conocarpus erectus and Phoenix reclinata is related to elevation and salinity. The storage of AGB and AGC is explained by salinity in Rhizophora spp. Similarly, the spatial localization of Rhizophora harrisonii is related to pH, temperature and atmospheric pressure. Nevertheless, biomass and carbon stock in Rhizophora harrisonii are determined by salinity and altitude. Also, Rhi-zophora racemosa has a geographic location determined by dissolved oxygen and pHmV; while its capacity, AGB, and AGC are related to pH and, to a lesser extent, dissolved oxygen.Les mangroves du Gabon, du nord au sud, couvrent trois complexes littoraux : estuarien, deltaïque et lagu-naire. Les espèces de mangroves pures rencontrées dans ces milieux sont Rhizophora racemosa, Rhizophora harriso-nii, Rhizophora mangle, Avicennia germinans, Laguncularia racemosa et Conocarpus erectus. L’étude portant sur la biomasse et le carbone aérien de ces mangroves est axée uniquement sur celles des estuaires du Komo, de la Mondah et du Rio Mouni. Les mangroves sont un des écosystèmes qui stocke le plus de biomasse et de carbone au monde. Dans un contexte de changement climatique, les estimations de stock de biomasse et de carbone des mangroves sont au centre des préoccupations scientifiques. Aussi, dans cette quête de quantification de biomasse et de carbone, le Gabon a une place importante. En effet, ses littoraux ont la plus grande richesse spécifique des mangroves de la sous-région Afrique Centrale et les mangroves les plus hautes sur la Terre. Ces particularités de ces mangroves suscite de disposer des outils locaux de prédiction de biomasse et de carbone. Afin de répondre à cette préoccupation, cette étude porte sur l’estimation et la spatialisation de la biomasse aérienne et du carbone des mangroves. Les outils de la géo-graphie sont mis à contribution pour estimer spatialement et expliquer les mécanismes de répartition de la biomasse dans les mangroves et dans les estuaires. La présente recherche a débouché sur la mise en place de 14 modèles, dont 10 modèles de prédiction au sol, notamment : 5 modèles de prédiction de volume, 5 modèles de prédiction de biomasse aérienne et 4 modèles de prédiction par télédétection (soit 3 modèles de prédiction de hauteur des mangroves à partir du SRTM et 1 modèle de prédiction de la biomasse aérienne (AGB) et de carbone à partir de la hauteur). La salinité, le pH, l’altitude, la pression atmosphérique, le pHmv, l’oxygène dissous et la température sont facteur de localisation des Avicennia germinans. La localisation spatiale de Laguncularia racemosa, Conocarpus erectus et Phoenix recli-nata est liée à l’altitude et à la salinité. Le stockage de l’AGB et l’AGC est expliqué par la salinité chez Rhizophora spp. De même, la localisation spatiale de Rhizophora harrisonii est liée au pH, à la température et à la pression atmos-phérique. Néanmoins, la biomasse et le stock de carbone chez Rhizophora harrisonii sont déterminés par la salinité et l’altitude. Aussi, Rhizophora racemosa a-t-il une localisation géographique déterminée par l’oxygène dissous et le pHmV ; tandis que sa capacité, son AGB et son AGC sont liés au pH et, dans une moindre mesure, à l’oxygène dissous

Recent advances in the fight against leishmaniasis with natural products

The active compounds obtained from some medicinal plants used traditionally worldwide for the treatment of leishmaniasis are reviewed. Among these active molecules described in recent literature are quinoline alkaloids such as alkyl-2 quinoline and aryl-2 quinoline from Galipea longiflora, isoquinoline alkaloids such as isoguattouregidine from Guatteria foliosa, indole alkaloids such as conodurine and gabunine from Pescheiera van heurkii, terpenes such as jatrogrossidione from Jatropha grossidentata, acetogenins such as senegalene from Annona senegalensis and lignans such as (+)nyasol from Asparagus africanus. Other natural compounds with antileishmanial activity are coumarins, chalcones, lactones, tetralones and saponins. Some of them are known antiprotozoal natural products. These compounds could be used as templates to discover new and effective drugs against leishmaniasis