Assessment of toxicity and clastogenicity of sterigmatocystin in Egyptian Nile tilapia

The increasing presence of genotoxic pollutants in the aquatic environment has led to the development of quick monitoring methods. Sterigmatocystin (Stg) is closely related to mycotoxins and has the carcinogenic potency in the experimental animal models. The exposure to genotoxic agents will give rise to alterations of DNA structure that can lead to abnormal changes of DNA fingerprints. Therefore, we have applied the random amplified polymorphism DNA (RAPD) method to evaluate the genotoxiceffects of Stg and to determine if the Egyptian montmorillonite (EM) has a protective effect against Stg. The experiment was conducted in vivo to evaluate the ability of EM at a level 0.5 mg/kg body weight(bw) to prevent the toxicity and genotoxicity induced by Stg in the Nile tilapia fish. Fishes were orally administrated with EM in corn oil with or without Stg (1.6 ìg/kg bw) twice a week for 4 weeks. Blood andtissue samples were collected at the end of the treatment. The results revealed that Stg had genotoxic and toxicopathological effects in Oreochromis niloticus fish. The genotoxic effects were indicated byappearance of some changes in polymorphism band patterns including lost of stable bands or occurrence of new bands. There also exists a distinct distance between the band patterns of exposed fish and protected or control fish samples. The effects on the tissues were manifested by different histopathological lesions in different organs including hyperplastic proliferation of branchial epithelium, necrobiotic changes in hepatic tissue and destruction of components of the spleen. These responses were virtually abolished or markedly decreased when fishes were exposed to EM combined with Stg. It could be conclude that addition of EM resulted in the inhibition of the toxicity andclastogenicity of St

Mitigation of Lightning Hazards at the More Sensitive Points in Wind Farms Using Ant-Colony Optimization Technique

The lightning energy can be very harmfull to the wind turbine farm components. This paper attempts to evaluate the overvoltages at the sensitive points in wind farm, using ATP-EMTP package program. Four cases were performed; a) the transient voltage distribution in the insulating layer of the control line, b) the transient voltage on the control equipment, c) the coupling voltage between the tower and the control, and, d) the transient voltage distribution in the wind turbine WT generator, boast transformers and grid. These cases were performed under different lightning current conditions and at conventional design and proper design of grounding system. The results show that the ground potential rise (GPR) is reduced with using the proper design of wind turbine ground system, but the induced voltage at the control system will not affected. This work determines the optimum location of wind turbine at the areas of maximum lightning incidence. Ant colony optimization (ACO) technique is implemented to find the optimum wind farm location. This work enhances the protection strategy of the wind farms against lightning stroke

Genetic variability of camel (Camelus dromedarius) populations in Saudi Arabia based on microsatellites analysis

The genetic diversity and population genetic structure of dromedary camels (Camelus dromedarius) are poorly documented in Saudi Arabia. The present study was conducted to address some of these genetics using four Saudi Arabian camel populations namely; Magaheem (MG), Maghateer (MJ), Sofr (SO) and Shual (SH). Genomic DNA was extracted from the hair roots of 160 camels, 40 individuals from each population. Sixteen microsatellite markers were used to genotype these 160 camels. Out of these 16 markers, only microsatellite VOLP67 did not produce any polymerase chain reaction (PCR) amplicons. There were 139 alleles generated by the 15 microsatellites loci with a mean of 9.27 alleles per locus. Four of the microsatellites loci studied in MG, eight in MJ and six in both SO and SH were found to be deviated from Hardy-Weinberg equilibrium. The fixation genetic indices (Fst) among the four populations were very low, ranging from 0.006 (between SH and SO) to 0.017 (between MG and MJ), indicating low population differentiation among the four Saudi camel populations. No significant heterozygote excess or bottleneck in most nearest past was detected in the four camel populations as indicated by sign, standardized differences and Wilcoxon tests, along with the normal L shaped distribution of mode-shift test. The present study showed that the microsatellite markers are powerful tools in breeding programs, although there is a need for applying more microsatellites in order to be able to discriminate fairly between camel populations of Saudi Arabia.Keywords: Camels, Camelus dromedarius, microsatellite markers, Saudi Arabia, genetic variabilit

Mitigation of Lightning Hazards at the More Sensitive Points in Wind Farms Using Ant-Colony Optimization Technique

The lightning energy can be very harmfull to the wind turbine farm components. This paper attempts to evaluate the overvoltages at the sensitive points in wind farm, using ATP-EMTP package program. Four cases were performed; a) the transient voltage distribution in the insulating layer of the control line, b) the transient voltage on the control equipment, c) the coupling voltage between the tower and the control, and, d) the transient voltage distribution in the wind turbine WT generator, boast transformers and grid. These cases were performed under different lightning current conditions and at conventional design and proper design of grounding system. The results show that the ground potential rise (GPR) is reduced with using the proper design of wind turbine ground system, but the induced voltage at the control system will not affected. This work determines the optimum location of wind turbine at the areas of maximum lightning incidence. Ant colony optimization (ACO) technique is implemented to find the optimum wind farm location. This work enhances the protection strategy of the wind farms against lightning stroke

Optically-enhanced performance of polymer solar cells with low concentration of gold nanorods in the anodic buffer layer

In this work, the effect of gold nanorods on the performance of poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric-acid-methyl-ester bulk heterojunction solar cells was investigated. Gold nanorods were introduced into the anodic buffer layer by simply blending them with the solution of poly(3,4-ethyl enedioxythiophene):poly(styrenesulfonate). Even with a fairly low density of the nanorods, the resulting devices showed a remarkable 21.3% enhancement in the power conversion efficiency and a 13% enlargement in the short circuit current. By examining the absorbance profiles of active films made with different conditions,\ud such enhancements can be related to the localized transverse and longitudinal plasmon resonance modes in the metallic nanoparticles. Gold nanorods helped as well in reducing the device series resistance by up to 36%, which also contributed to the global enhancement in the efficiency

Correlating novel variable and conserved motifs in the Hemagglutinin protein with significant biological functions

<p>Abstract</p> <p>Background</p> <p>Variations in the influenza Hemagglutinin protein contributes to antigenic drift resulting in decreased efficiency of seasonal influenza vaccines and escape from host immune response. We performed an in silico study to determine characteristics of novel variable and conserved motifs in the Hemagglutinin protein from previously reported H3N2 strains isolated from Hong Kong from 1968–1999 to predict viral motifs involved in significant biological functions.</p> <p>Results</p> <p>14 MEME blocks were generated and comparative analysis of the MEME blocks identified blocks 1, 2, 3 and 7 to correlate with several biological functions. Analysis of the different Hemagglutinin sequences elucidated that the single block 7 has the highest frequency of amino acid substitution and the highest number of co-mutating pairs. MEME 2 showed intermediate variability and MEME 1 was the most conserved. Interestingly, MEME blocks 2 and 7 had the highest incidence of potential post-translational modifications sites including phosphorylation sites, ASN glycosylation motifs and N-myristylation sites. Similarly, these 2 blocks overlap with previously identified antigenic sites and receptor binding sites.</p> <p>Conclusion</p> <p>Our study identifies motifs in the Hemagglutinin protein with different amino acid substitution frequencies over a 31 years period, and derives relevant functional characteristics by correlation of these motifs with potential post-translational modifications sites, antigenic and receptor binding sites.</p

Phototherapy and DNA changes in full term neonates with hyperbilirubinemia

Background: Phototherapy has remained the standard therapeutic approach for neonatal hyperbilirubinemia. Oxidative effects of phototherapy on cell membranes and cell components may have a wide range of potential adverse effects, including enhanced lipid peroxidation and DNA damage. Apoptosis is an indispensable mechanism for maintaining many cellular functions, including cell replication, and removal of damaged cells with high burden of genetic mutations. Many genes function as apoptosis regulatory genes. Examples of these genes include the BCL2 gene which is an anti-apoptotic oncogene, and the BAX gene which acts as a promoter of apoptosis.Objectives: Assess the effect(s) of phototherapy on DNA and on the rate of apoptosis in full term neonates with hyperbilirubinemia. It comprised 35 neonates with indirect hyperbilirubinemia who received phototherapy for 48h, and 20 apparently healthy full term neonates with normal serum bilirubin level, as a control group. DNA damage was assessed by DNA fragmentation and micronucleus assay. Determination of the anti-apoptotic effect(s) of BCL2 gene was achieved by quantitative assay of its product, (BCL2) protein, by ELISA and BAX gene expression status was assessed by PCR.Results: The frequency of micronuclei in circulating lymphocytes of neonates who received phototherapy has significantly increased before and after phototherapy compared to controls, (p&lt; 0.001; p&lt; 0 0.00001), respectively. DNA fragmentation in circulating lymphocytes, was significantly higher among cases before and after phototherapy compared to controls (p&lt; 0.0001; p&lt; 0 0.00001). The plasma BCL2 protein was significantly lower in the cases before and after phototherapy compared to controls (p&lt; 0.01; p &lt;0.01), respectively, and BAX gene expression was significantly high among cases before and after phototherapy compared to controls.Conclusions: Geno toxic effects of bilirubin and phototherapy, induce more DNA damage and enhances apoptosis of exposed cells, probably through down regulation of BCL2 expression and upregulation of BAX gene expression in neonates with hyperbilirubinemia. Keywords: Hyperbilirubinemia; Phototherapy; DNA damage; Apoptosis; BCL2 gene; BAX gen