With digital equipment becoming increasingly networked, either on wired or wireless networks, for personal and professional use alike, distributed software systems have become a crucial element in information and communications technologies. The study of these systems forms the core of the ARLES' work, which is specifically concerned with defining new system software architectures, based on the use of emerging networking technologies. In this context, we concentrate on the study of distributed systems which bring to life the vision of ubiquitous computing systems, also known as ambient intelligence.

반도체 공정 overview

The pollution of rivers and lakes is of concern because of the threat to public water supplied and because of the damage caused to natural ecosystems. Waterborne diseases remain rife in the Third World, while in developed countries there has been a decline in the quality of water. It has also become apparent that pollutants may destroy ecosystems hundreds of miles from their source. Some of these toxic materials such as lead and PCBs also pose threats to public health. This text describes the sources of various types of pollutants, their effects on aquatic organisms, ecosystems and man, using case histories where appropriate. Ways of mitigating the effects of pollutants by control and ecosystem manipulation are described. Techniques for assessing the effects of pollution, both in field and laboratory, are introduced. The role of the biologist in pollution assessment and control and in the wider sphere of mangement of acquatic resources is also examined.

Biology of Freshwater Pollution.

The present review gives a brief account of the toxic effects of heavy metals on fish. In aquatic ecosystem, heavy metals are considered as the most important pollutants, since they are present throughout the ecosystem and are detectable in critical amounts. Heavy metals, such as mercury, cadmium, copper, lead and zinc are of the most important pollutants which effect aquatic environment and fish. They are extremely dangerous for the health of fish. Most of these metals are characterized by being accumulated in tissues, and lead to the poisoning of fish. These metals can effectively influence the vital operations and reproduction of fish; weaken the immune system, and induce pathological changes. As such, fish are used as bio-indictors, playing an important role in monitoring heavy metals pollution. Finally, some recommendations are given to treatment of different kinds of wastewaters, sewage and agricultural wastes before discharge into the aquatic systems. Also, enforcement of laws and legislations regarding the protection of aquatic environments must be taken into consideration.

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Use of Fish as Bio-indicator of the Effects of Heavy Metals Pollution

Effect of heavy metals on fish larvae deformities: A review.

A review on the application of Bacillus as probiotics in aquaculture

The present study was conducted to investigate whether the combined treatment with Se and Zn offers more beneficial effects than that provided by either of them alone in reversing Cd-induced oxidative stress in the kidney of rat For this purpose, 30 adult male Wistar albino rats, equally divided into control and four treated groups, received either 200 ppm Cd (as CdCl2), 200 ppm Cd + 500 ppm Zn (as ZnCl2), 200 ppm Cd + 01 ppm Se (as Na2SeO3), or 200 ppm Cd + 500 ppm Zn + 01 ppm Se in their drinking water for 35 days The results showed that Cd treatment decreased significantly the catalase (CAT) and glutathione peroxidase (GSH-Px) activities, whereas the superoxide dismutase (SOD) activity and the renal levels of lipid peroxidation (as malondialdehyde, MDA) were increased compared to control rats The treatment of Cd-exposed rats with Se alone had no significant effect on the Cd-induced increase in the MDA concentrations but increased significantly the CAT activities and reversed Cd-induced increase in SOD activity It also partially prevented Cd-induced decrease in GSH-Px activity The treatment of Cd-exposed animals with Zn alone increased significantly the CAT activity and partially protected against Cd-induced increase in the MDA concentrations, whereas it had no significant effect on the Cd-induced increase in SOD activity and decrease in GSH-Px activity The combined treatment of Cd-exposed animals with Se and Zn was more effective than that with either of them alone in reversing Cd-induced decrease in CAT and GSH-Px activities and Cd-induced increase in MDA concentrations Results demonstrated beneficial effects of combined Se and Zn treatment in Cd-induced oxidative stress in kidney and suggest that Se and Zn can have a synergistic role against Cd toxicity

Protective effects of selenium, zinc, or their combination on cadmium-induced oxidative stress in rat kidney.

Protective effect of zinc supplementation on blood antioxidant defense system in rats exposed to cadmium

The present study was designed to elucidate the protective effect mechanism of Zinc (Zn) and Selenium (Se) on cadmium (Cd)-induced oxidative stress in zebrafish. For this purpose we investigate the response of oxidative stress markers, metallothionein accumulation and gene expression in liver and ovary of female zebrafish exposed to 0,4 mg/l Cd in water and supplemented with Zn (5 mg kg−1) and/or Se (2 mg kg−1) for 21 days in their diet. Liver and ovary Cd uptake was evaluated after the exposure period. Cd exposure significantly inhibited the antioxidant enzyme activities termed as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxydase (GPx) and caused a pronounced malondialdehyde (MDA) accumulation in both organs. Co-administration of Zn and Se reversed the Cd-induced toxicity in liver and ovary measured as MDA accumulation. Interestingly, gene expression patterns of Cat, CuZnSod and Gpx were up-regulated when related enzymatic activities were altered. Zebrafish metallothionein transcripts (zMt) significantly decreased in tissues of fish supplemented with Zn and/or Se when compared to Cd-exposed fish. Our data would suggest that Zn and Se protective mechanism against Cd-induced oxidative stress is more depending on the correction of the proteins biological activities rather than on the transcriptional level of related genes.

Mechanisms underlying the protective effect of zinc and selenium against cadmium-induced oxidative stress in zebrafish Danio rerio.

Influence of combined treatment with zinc and selenium on cadmium induced testicular pathophysiology in rat.

To select a marine teleost fish which can be used as a bioindicator of cadmium (Cd) pollution in the Gulf of Gabes in Tunisia, Cd concentrations in liver and gill were compared in three benthic fish species including Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris. Fish samples were collected from three selected sites in the Gulf of Gabes, with different degrees of Cd contamination: the industrialized coast of Sfax (S1), the coast of Douar Chatt (S2) and the coast of Luza (S3). The results shows that Cd concentrations in both sediment and water collected from S1 were significantly higher (p S2 > S3. The highest concentration of Cd was detected in the liver of S. basilisca, and only S. basilisca showed bioaccumulation factors (BAF) greater than 1 in all studied sites. In S1 and S2, BAF values respect the following order: S. basilisca > Z. ophiocephalus > S. vulgaris. These results of significant bioaccumulation of Cd, in terms of hepatic concentrations and bioaccumulation factors, indicated that S. basilisca can be used as bioindicator to evaluate the evolution of Cd pollution in the Gulf of Gabes.

Cadmium bioaccumulation in three benthic fish species, Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris collected from the Gulf of Gabes in Tunisia.

Imed Messaoudi

Papers

Protective effects of selenium, zinc, or their combination on cadmium-induced oxidative stress in rat kidney.

Protective effect of zinc supplementation on blood antioxidant defense system in rats exposed to cadmium

Mechanisms underlying the protective effect of zinc and selenium against cadmium-induced oxidative stress in zebrafish Danio rerio.

Influence of combined treatment with zinc and selenium on cadmium induced testicular pathophysiology in rat.

Cadmium bioaccumulation in three benthic fish species, Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris collected from the Gulf of Gabes in Tunisia.