No abstract

The results indicate a low prevalence of teeth with radiographic periapical disease, a low prevalence of root-filled teeth and a high prevalence of unacceptable root fillings.

Although the anthocyanin content and initial colour were not modified, the extraction conditions, especially temperature, greatly affected the stability of the extracts during storage. Further studies are needed to understand the mechanisms involved.

The response of microbial functional diversity as well as its resistance to stress or disturbances caused by the introduction of an exotic tree species, Acacia holosericea, ectomycorrhized or not with Pisolithus albus, was examined. The results show that this ectomycorrhizal fungus promotes drastically the growth of this fastgrowing tree species in field conditions after 7 years of plantation. Compared to the crop soil surrounding the A. holosericea plantation, this exotic tree species, associated or not with the ectomycorrhizal symbiont, induced strong modifications in soil microbial functionalities (assessed by measuring the patterns of in situ catabolic potential of microbial communities) and reduced soil resistance in response to increasing stress or disturbance (salinity, temperature, and freeze-thaw and wet-dry cycles). In addition, A. holosericea strongly modified the structure of arbuscular mycorrhizal fungus communities. These results show clearly that exotic plants may be responsible for important changes in soil microbiota affecting the structure and functions of microbial communities.Forest loss and degradation through human disturbance as well as deterioration of land productivity is a major problem in large areas of arid and semiarid environments. Degraded soils are characterized by loss or disturbance of the vegetation cover, increased soil erosion, decreased in-water infiltration, loss of available nutrients and organic matter, loss of microbial propagules, and/or diminution in microbial activity (25,35,44). Restoration of ecosystem health and productivity was traditionally achieved via abandonment of land and subsequent natural forest succession. In recent decades, management options for acceleration of the recovery and restoration of the productivity and biodiversity of disturbed ecosystems have been considered, since fallow periods have been shortened or eliminated due to increased anthropogenic pressure and agriculture intensification (49). Concerning the techniques used for rehabilitating degraded areas, there is increasing evidence that forest plantations can play a key role in ecosystem rehabilitation or restoration (52). Among candidate plantation species, fast-growing leguminous tree species (e.g., Australian Acacia species) should have preference.

Plante herbacée annuelle, à plusieurs propriétés, le sésame (Sesamum Indicum L.) a été introduit au Sénégal pour une rotation et une diversification des cultures afin d'augmenter la productivité et les revenus des populations rurales et contribuer à la sécurité alimentaire. Afin d'améliorer les conditions de culture du sésame, des recherches ont été entreprises sur cette plante oléagineuse. L'objectif de cette étude était de faire une revue de la composition, l'état de la recherche et les utilisations du sésame au Sénégal. Les recherches bibliographiques ont permis de montrer quelques acquis au plan de la recherche. C'est le cas de la connaissance des conditions pédoclimatiques et les techniques de culture de cette plantation au Sénégal. Les paramètres agro-morphologiques de la plante et l'amélioration variétale par les phénomènes de mutation ou de mycorhization ont également été étudiés. Les futurs programmes de recherche devraient mettre l'accent sur la composition biochimique, nutritionnelle et minérale, ainsi que sur son utilisation et sa biotransformation, de même que sur les aspects de défense des cultures et phytosanitaires de ces produits dérivés.