Ressources alimentaires non conventionnelles

Unconventional Food Resources. Concepts of ethnobotany, ethnozoology and ethnoecology are defined and their respective development recounted. The geographic frame is afterwards specified: Tropical Africa. Diversity of wild edible vegetable products is illustrated by some examples: cyanobacteria from Chad, mushroom consumption in the Zambezian region and pteridophagy. Upper plants are approached according to six ensembles, namely starchy fruits and seeds, oilseeds and nuts, fleshy fruits, reserve organs, flowers and vegetable species. After recalling the diversity of insects eating at world scale, four orders are briefly presented: coleoptera, isoptera (termites), lepidoptera (mainly caterpillars or campeophagy) and orthoptera. Finally the nutritional input of unconventional foods is underlined as well as the urgent need of their further studies

Early stages of natural revegetation of metalliferous mine workings in South Central Africa: a preliminary survey

The various types of mining sites resulting from human activities in the Katangan Copper Bow and the Zambian Copperbelt are described and a typology is presented whereby ten different situations are recognized. Performance as well as distribution of the diverse plant species observed on these sites is considered. A set of nine ecological conditions is suggested, based both upon the heavy metal content of soil as well as its state of hydration. One taxon is identified as an indicator of each condition recognized. The information presented here is a preliminary requirement for planning the revegetation of metalliferous sites within the area

Structure diversity in three forest types of north-eastern Thailand (Sakaerat Reserve, Pak Tong Chai)

The aim of the present study is to provide a basic knowledge in view of a better understanding of the global structure of threetropical forests at the Sakaerat Environmental Research Station (Pak Tong Chai district, Northeastern Thailand): a drydipterocarp forest (DDF), a dry evergreen forest (DEF) and an intermediate stage (DDFwf), characterized by the absence offire since 29 years in a pyro-climax. These forest ecosystems were contrasted by the composition and floristic structure, thebasal area and the tree density. The species richness increases with the passage from the DDF, the most open environment, to the DDFwf, the most densely wooded. By these tree density and basal area, the DDF (602 trees/ha at DBH ³ 5 cm, 14.2 m2/ha) and the DEF (992 trees/ha at DBH ³ 5 cm, 29.0 m2/ha) studied belong to the typical tropical ecosytems of southeast Asia. The man-made fires and anarchic forest exploitations are a danger for the stability of these different ecosystems

Porin Proteins in Mitochondria from Rat Pancreatic Islet Cells and White Adipocytes

The binding of hexo-/glucokinase and glycerol kinase to mitochondria via the channel forming protein, porin, in pancreatic islet β-cells and adipocytes, was recently proposed to participate in nutritional signaling, glucose sensing, and the control of high-energy phosphate distribution and oxidative phosphorylation. In this study we demonstrate that polyclonal antisera against purified rat liver porin recognize unique proteins in rat pancreatic islets, adipocytes, and RINm5F cells, each with an apparent Mr about 2000 smaller than that of liver porin. Immunoblotting of subcellular fractions, the purity of which has been controlled by the distribution of marker proteins, revealed the mitochondrial localization of the cross-reacting proteins. Their enrichment with a method used for the purification of porin proteins, the characteristic behavior during isoelectric focusing, and the specific binding of rat liver hexokinase and glycerol kinase to phospholipid vesicles containing the purified cross-reacting β-cell or adipocyte proteins strongly suggest their identity with mitochondrial porin. The subtle differences in the apparent Mr and charge heterogeneity raise the possibility of the existence of porin isoforms expressed in a tissue-specific manner. Anti-porin antisera coimmunoprecipitated hexo-/glucokinase from rat insulinoma cell (RINm5F) and adipocyte mitochondria as determined by subsequent immunoblotting of the immunoprecipitates with polyclonal antisera against yeast hexokinase and rat liver glucokinase, respectively. This indicates that some rat pancreatic glucokinase (54 kDa) and liver hexokinase (102 kDa), respectively, is bound to mitochondrial porin. The major portion of the bound fraction is released from mitochondria after treatment with glucose 6-phosphate. Incubation of RINm5F and fat cells with the insulin releasing sulfonylurea drug, glimepiride (20 nM and 5 μM, respectively) for 30 min reduces the amount of hexo-/glucokinase associated with mitochondria and porin to about 50-30%. The reduced kinase binding activity of porin is preserved after isolation of porin from glimepiride-treated cells, reconstitution into phospholipid vesicles and assaying for glucose 6-phosphate inhibitable binding of rat liver hexokinase. The sulfonylurea tolbutamide (20 μM and 5 mM) is significantly less effective. The sulfonylurea-induced inhibition of hexo-/glucokinase binding to mitochondrial porin does not require glucose metabolism or Ca2+ influx into the cells. These data suggest that the sulfonylurea glimepiride, which is thought to inhibit the ATP-regulated K+-channel in β-cells, may have, in addition, an intracellular site of action in pancreatic islet and adipocyte cells at the level of regulation of gluco-/hexokinase binding to mitochondrial porin

Floristic and phytogeographical analysis of Djoumouna forest (Republic of Congo)

peer reviewedLa forêt de la Djoumouna est située à 24 km au sud-est de Brazzaville. Pour mieux connaître sa richesse floristique et sa position chorologique, une analyse de la florule, des spectres autoécologiques et phytogéographiques des espèces a été entreprise. Cette étude a été effectuée à partir du matériel floristique provenant de différentes prospections botaniques, collection de référence déposée à l’Herbier National du Congo (IEC). Sur une superficie de 8,5 hectares prospectée, 458 espèces dont quatre nouvelles pour la République du Congo, ont été inventoriées. Elles appartiennent à 102 familles et 309 genres. Les familles des Fabaceae, des Rubiaceae, des Euphorbiaceae, des Poaceae, des Apocynaceae et des Malvaceae sont les plus diversifiées en nombre d’espèces. Les spectres écologiques mettent en évidence la forte représentativité des phanérophytes, des mésophylles, des sarcochores et des espèces de la classe des Strombosio-Parinarietea, confirmant de facto la nature et la maturité forestières du site. Sur le plan phytogéographique, la prépondérance de l’élément base décelé ainsi que la présence de deux familles et de huit genres endémiques, intègrent bien cette florule au Centre d’endémisme guinéo-congolais, au carrefour des domaines congolais et bas-guinéen. En dehors de quelques cas isolés d’impact sur la flore et la végétation, une attention particulière doit être apportée à cet écosystème fragile, en vue de son aménagement à titre conservatoire, de la sauvegarde de sa richesse floristique et comme régulateur du climat local et puits de séquestration du carbone

Ophioglossum polyphyllum A. Braun in Seub. (Ophioglossaceae, Pteridophyta), a rare potherb in south central Tibet (T.A.R., P.R.China)

peer reviewe

Key to the identification of the final instar caterpillars eaten in Congo-Brazzaville

peer reviewedLa consommation humaine de lépidoptères est un thème d’actualité, mais pour lequel aucune synthèse n’a été rédigée en ce qui concerne la République du Congo-Brazzaville. Les nombreuses et récentes explorations de terrain ont montré que près d’une trentaine d’espèces de chenilles sont consommées. L’établissement d’une clef de détermination soutenue par des illustrations claires et précises apporte dès lors un outil fondamental pour un inventaire ethnozoologique efficace. La clef que nous proposons dans cet article se veut simple, complète et potentiellement évolutive