We proposed to undertake an experimental study on the combined toxicity of Lead and Cadmium in aquatic environment, for describing well the danger which run the alive beings which live there and on which the life depends on it.
To achieve our goal, we used as biological material Gambusia affinis, a species sensitive to toxicity in order to check if the combined effects of heavy metals in fact Plomb and Cadmium would be the cause of disturbance in aquatic environment.
We proceeded to test each salt individually and to determine the CL50 of them;then, to prepare a solution combined with the concentrations corresponding to the value of ½ CL50 of these two salts tested according to méthode(5).
Taking into consideration these results obtained, the constant following is released:The Cadmium tested with the concentration of 0,1 G and its dilutions, is very toxic with a CL50 around 0,003 Mg that the solutions of Lead to the same concentration with a CL50 around 0,006 Mg.
The biological tests of laboratory made it possible to prove the toxicity of each salt separately and to confirm the combined toxicity of these two heavy metals, owing to the fact that the combination of their ½ CL50 gives synergistic effects to the populations of Gambusia affinis.
This study will precisely allow the scientific community, to the industrialists, and the government to manage our environment well, in order to especially avoid the danger due to the pollution with heavy metals which constitutes today a plague threatening the species of the aquatic environment, water, and the life of the human beings in general, in the mine fields of the DRC being a significant mining country.
La Province du Sud-Kivu est l’une de 26 provinces que compose la République Démocratique du Congo située à l’est du pays. Les années de guerre n’ont évidemment pas profité à l’économie de la province, quasi à l’arrêt aujourd’hui. Le Sud-Kivu a en effet servi de porte d’entrée aux différentes guerres d’agression que le pays a connues et dont les conséquences sont encore importantes sur la vie socioéconomique de la province. Un des grands problèmes majeurs de cette province, en particulier et de la RDC, en général, est l’insuffisance et l’état en délabrement avancé des infrastructures de transport qui rend difficile la circulation des personnes et des biens. Autant son isolement externe criant, autant à l’intérieur du territoire national l’enclavement est réel et pose un véritable problème de développement, de par son étendu territorial, son enclavement et une situation de fragilité économique constituent les éléments fondamentaux du contexte dans lequel évolue le secteur des transports. Suite à cet état, le secteur aérien demeure le seul moyen pouvant relier les grands centres pour ainsi faciliter les échanges commerciaux. Ce caractère fondamental de coopération très étroite du secteur aérien unit le pouvoir public et l’initiative privée pour le renforcement du pouvoir économique en vue de participer au développement de la province.
Within an organizational setting characterized by a continuous production or services evolution and known by the emergence of a new era of information technologies, the leaders/managers are in the obligation to seek an optimal management mode by practicing a layback and a critical scrutiny of their managerial strategies. The application of the coaching method is hence regarded as practical tool box capable of stimulating the professional action by pushing forward the managers to use a variety of actions able to generate new behaviours more appropriate and more beneficial than those already practiced by the managers.
The textbook is a learning tool that helps learners to develop positive attitudes, knowledge and skills. This implies that the textbook offers situations based on a variety of scientific approaches. The experimental approach is one of the most widely used approaches in life and earth science teaching and contributes to the preparation of an individual able to adapt to his or her environment. In this context, the question arises to what extent the life and earth science textbook integrates the steps of the experimental approach? To answer this question, we have analyzed the "Fi Rehab Life and Earth Sciences" textbook of the third year of secondary education. This analysis has shown that some stages of the experimental approach have been well developed while others are neglected. This requires extra effort when revising or designing textbooks, taking into account all stages of the experimental approach and focusing on the learner. The latter is the most important clue in the development of the teaching and learning process.
This scientific publishing was about the phytochemical screening and evaluation of anti-diarrheic activity of aqueous and ethanol extracts of Spilanthes Mauritiana plant. The process consisted to the qualitative chemical analysis of natural substances contained in and anti-bacterial test of their aqueous and ethanol extracts on bacterial stumps. Final result showed that the plant contain 85% of researched actives ingredients, and 50% of these ingredient was efficient to bacterial stumps as are some witness anti diarrheic drugs.
These justify the traditional treatment of diarrhea with Spilanthes Mauritiana.