Phytoremediation potential of Raphanus sativus L. for lead contaminated soil

Phytoremediation is an emerging technology that employs the use of higher plants for the clean up contaminated environment. Phytoextraction, the use of plants to extract toxic metals from contaminated soils, has emerged as a cost-effective, environment-friendly clean up alternative. Pot culture experiments using radish (Raphanus sativus L.) was performed to investigate lead (Pb) phytotoxic effects on antioxidant enzymes and other early warning biomarkers of soil Pb exposure. The study included an assessment of heavy metal accumulation in root, shoot and leaf, effect of lead stress on growth parameter (root length, root and shoot dry weight), photosynthetic pigment content, bioaccumulation coefficient (BAC) and the activity of anti-oxidant enzymes. Results demonstrated that efficient Pb uptake was observed by the roots in contaminated plants. Root growth was higher in control plants, as compared to the contaminated. Lead exposure also influenced biochemical and physiological parameters. Administration of excess of lead was followed by an increase of Pb accumulation in leaves, and associated symptoms of toxicity. Typical symptoms of Pb toxicity developed 30 days after the beginning of treatment. Chlorophyll concentration was decreased in response to heavy metal toxicity. Activity of anti-oxidative enzymes e.g. peroxidase and catalase were increased in response to oxidative stress. Atomic absorption spectrophotometer (AAS) was used for analysis of heavy metal in soil and plant samples. The results of this research showed that radish are hyperaccumulator plants that can concentrate heavy metals in their different parts, thus they can be used for remediation of polluted area. Study also showed that potential of metal accumulator plants for extraction of metal from soil occur up to a certain level of concentration, after that when the concentration of metal increased the phytoextraction rate of metal or bioaccumulation coefficient (BAC) were decreased

Algeria post Arab Spring: The Forced Virtualisation of the Borders

Algeria is the core of the Maghreb and shares land borders with seven countries Maghreb and Sahel countries. However, since 2011, none of the seven land borders is stable and se-cure. So, even if Algeria is considered as a stable country, this stability is fragile and is likely to be more precarious if the country has to face simultaneously an economic crisis and deli-cate presidential succession. Domestic incertitude coupled to regional conflicts puts the Algerian borders under unprecedented pressure. Consequently, almost all the governmental declarations expressed worries about the vulnerability of the borders, and assurances about the security services determination to assure the state security. However, to what extant this promise can be entirely fulfilled, regarding the borders’ characteristics and the specificity of the context? Why is the virtualization of the borders forced? As regards to the growing per-meability of the borders, can their militarization guarantee their security

Diversity of Algerian basidiomycetes, morphological, macrochemical and genotypic characterisation

A collection of 16 basidiomycetes was carried out in northwestern Algeria. During the harvest, the average temperature of the sites was between 11.2 to 19.3 °C with an average humidity of 67 to 90%.  The dominant plants observed at the sampling sites are pine, oak and false pepper. The collected mushrooms were identified by their macroscopic, microscopic (light microscope and scanning electron microscope) and macrochemical characteristics using chemical reagents to distinguish among the different species. Of the 16 fungi, a genotypic identification was made using the tools of molecular biology and bioinformatics analysis.  The results of the phenotypic analysis showed that the fungi in question were: Lactarius zonarioides, Amanita proxima, A. virosa, Agaricus bisporus, Suillus mediterraneensis, Boletus sp., Xerocomus sp., Coprinus atramentarius, Pleurotus ostreatus, P. pulmonarius, P. eryngii, P. dryinus, Lepiota sp., Cortinarius orellanus, Armillaria mellea and Trametes quercina. The comparison of the ITS1 sequences (143 bp) with those of the databases was carried out using the BLAST algorithm, which confirmed the identification of Agaricus bisporus.&nbsp

Multiscale modeling of the mesotexture of C-S-H and ASR gels

International audienc

Nanomechanics of ASR Gels from Coarse-Grained Simulations

International audienc

Open review of "Machine learning and micromechanics as allies to establish composition-property correlations in cement pastes"

This is the Open Review of the article https://doi.org/10.46298/jtcam.9830 published in JTCA

Lead Toxicity and The Hypothalamic-Pituitary-Testicular Axis

Environmental exposure to toxic levels of lead (Pb) occurs in a number of industries with potential adverse effects on the reproductive capacity of exposed men. Clinical and animal studies indicate that abnormalities of spermatogenesis result from toxic lead exposure, but eventual histopathologic alterations involved have not been identified. To explore putative abnormalities in the reproductive gonadotropic axis following lead intoxication, experimental animals when exposed to low levels of lead, 65 days old animals were treated with distilled water containing 0, 0 mg (control), 10 mg lead (Pb)/Kg/day and 15 mg lead (Pb)/Kg/day intraperitoneally for 20 days. At the end of treatment, the animals were sacrificed and the blood collected for luteinizing hormone (LH) and testosterone assays. The testis was processed for histological analysis. The results showed a high serum concentration of LH and testosterone in lead-treated animals compared to controls. Histological examination of testis showed deformities in testicular morphology of lead intoxicated animals with gross damage within the somniferous tubules. A strong correlation was established between LH and testosterone suggesting an alteration in the endocrine components of the gonadotropic axis. Histological examination of pituitary gland showed some degenerative changes in endocrine cells of lead group. Changes in LH and testosterone levels suggest that Pb exposure during the critical time of sexual differentiation induces reproductive axis abnormalities in adulthood. In conclusion, lead has a gonadotoxic effect by decreasing LH and testosterone levels and damaging the testis seminiferous tubules. Catalase activity was significantly reduced in the lead group following 65 days of exposure which possibly indicates that lead might had other mechanisms of action, such as increasing oxidative damage

Beneficial Effect Administration of Vitamin C in Amelioration of Lead Hepatotoxicity

Previous human and experimental studies have demonstrated that lead exposure may modify the metabolism of lipid. Oxidative stress with subsequent lipid peroxidation has been postulated as one mechanism for lead toxicity. The protective action of vitamins C against lead affects lipid hydroperoxide level and liver functions in male rats has been studied. Experiments were performed on male waster rats with body weights of 120-160 g. Male wistar rats were exposed to 3 g/l lead acetate in drinking water for 5 weeks and treated thereafter with vitamin C (500 mg/kg, orally) for 28 days. One day after the feeding was over, venous blood samples, under chloroform anesthesia, were collected. The animals were killed by exsanguinations and the liver was excise for determination the metal content and histopathological changes. Similarly, the tissue lipid (lipid peroxidation) and the enzyme fraction (superoxide dismutase (SOD), catalase (CAT), alkaline phosphatase (ALP), acid phosphatase (ACP) and glutathione (GSH) were also measured in the liver. Metal content in blood and liver was determined by means of atomic absorption spectrophotometry. Administration of lead acetate (3 g/l) in drinking water for 5 weeks induced a significant increase in the levels of hepatic ALP, ACP and lipid peroxidation. Lead acetate exposure also produced detrimental effects on the redox status of the liver indicated by a significant decline in the levels of liver antioxidants such SOD, CAT and GSH. Further, there was a significant increase in the levels of lead in blood and liver of animals exposed to lead. However, oral administration of vitamin C at dose level of 500 mg/kg body weight reduced the alterations in the previous parameters. Histological examination of the liver also revealed pathophysiological changes in lead acetate-exposed group and treatment with vitamin C improved liver histology. The result of this study strongly indicate that vitamin C has got a potent antioxidant action against lead acetate induced hepatic damage in rats