Dynamique Des Eléments Nutritifs Et Du Phytoplancton Dans Le Barrage Béni Haroun Dans l’Est Algérien

In order to monitor the water quality of the Beni Haroun dam, used for the drinking water production, our research work aims to provide new scientific data on the phytoplankton population of the dam. This contribution is a qualitative and quantitative investigation of this important link in the ecosystem equilibrium. To our knowledge, this study has never been the subject of a previous one, despite many works already done on this dam. Water samples were collected monthly from January to December 2015 at five stations, spread over Beni Haroun dam. The exploitation of a database, relating to fourteen physicochemical and biotic variables, made it possible to determine: the spatiotemporal evolution of each variable, the correlations between variables, the annual variability of the algal biomass, the diversity and phytoplankton dominance

The control parameterization method for nonlinear optimal control: A survey

The control parameterization method is a popular numerical technique for solving optimal control problems. The main idea of control parameterization is to discretize the control space by approximating the control function by a linear combination of basis functions. Under this approximation scheme, the optimal control problem is reduced to an approximate nonlinear optimization problem with a finite number of decision variables. This approximate problem can then be solved using nonlinear programming techniques. The aim of this paper is to introduce the fundamentals of the control parameterization method and survey its various applications to non-standard optimal control problems. Topics discussed include gradient computation, numerical convergence, variable switching times, and methods for handling state constraints. We conclude the paper with some suggestions for future research

Chlorpyrifos-induced oxidative stress and tissue damage in the liver, kidney, brain and fetus in pregnant rats: the protective role of the butanolic extract of **Paronychia argentea** L.

Objective : Toxicity of pesticides is thought to be due to reactive oxygen species (ROS). Due to their antioxidant property, polyphenols in plant extracts may afford protection from pesticide toxicity. In the present study, we evaluated the protective effect of a butanolic extract of Paronychia argentea L. against toxicity caused by the organophosphorus pesticide, chloropyriphos ethyl (CE). Materials and Methods: Pregnant albino Wistar rats were used. Pesticide and plant extract were administered daily by oral gavage from the 6 th to the 15 th day of gestation. Plasma and tissue malondialdehyde (MDA), blood reduced glutathione (GSH) and erythrocyte superoxide dismutase (SOD) activities were estimated. MDA levels were estimated in plasma and different organs (liver, kidney, brain, placenta and in the fetuses and their livers) as an indicator of lipid peroxydation (LPO). Results: The data showed a significant increase in plasma and tissue LPO levels in animals treated with the pesticide while the effect was attenuated by the plant extract (CE-ex). Also, CE caused a significant decrease in antioxidant enzyme activity and this effect was partially reversed in groups treated with the plant extract. The pesticide induced embryotoxicity and resulted in resorption, fetal death and a reduced implant number. Conclusion : It can be concluded that CE can lead to an increase in LPO production in adult and fetal tissues, while treatment with the plant extract leads to protection against CE toxicity. The decrease in LPO levels and the increase in GSH and SOD enzyme activities after treatment with the plant extract revealed its antioxidant property

The protective effect of Chrysanthemum fantanesii extract, vitamin E and C on sodium valproate-induced embryotoxicity in pregnant mice

investigated the ability of butanolic extract from leaves of Chrysanthemum fantanesii, vitamin E and C to modulate VPA-induced toxicity and oxidation damage in maternal and fetal tissues in mice. Plant extract, VPA and vitamins were administered orally to pregnant mice from the 6 to 17th day of gestation. Animals received plant extract (200 mg/kg per day), vitamin E (100 mg/kg per day) and vitamin C (8.3 mg/kg per day) with an oral administration of VPA (400 mg /kg per day) under the same conditions. On day 18 of gestation pregnant mice were sacrificed, fetuses, placenta and maternal tissues were removed, homogenized and used for the determination of lipid peroxidation rates (LPO) using thiobarbituric acid reactive substance (TBARS) method. Embryotoxicity was assessed by counting the number of implants, live and dead fetuses, and resumptions. The fetuses were observed for malformation including neural tube defect (Exencephaly), open eyes and skeletal malformation. The results show clearly that there is a positive correlation between the increase in LPO and congenital malformation. Plant extract, vitamin E and C caused partial decrease of embryo toxicity and congenital malformation induced by VPA in mic