Improving hadoop performance in heterogeneous big data environments by dynamic slot configurations in mapreduce hadoop programming model
Journal ArticleHadoop has been developed as a platform solution for processing a large scale of data in parallel for different applications in Cloud com-puting. A Hadoop system can be characterized based on three main factors: cluster, workload, and user. Each of these factors can be described in heterogeneous environment, which reflects the heterogeneity degree of the Hadoop system. This paper investigates the effect of heterogeneity in each of these factors on the performance of Hadoop for different schedulers. Three schedulers which consider differ-ent levels of Hadoop heterogeneity are used for the analysis: FIFO, Fair sharing, and COSHH (Classification and Optimization based Scheduler for Heterogeneous Hadoop). Performance issues are introduced for Hadoop schedulers and comparative performance analysis between different cases of jobs submission. These jobs are processed in heterogeneous data environments and, under fixed or reconfigu-rable slot between map and reduce tasks for Hadoop MapReduce java programming clustering model. The results showed that when assigning tunable knob between map and reduce tasks under certain scheduler like FIFO algorithm, the performance enhanced about 81.42% especially in cases of heterogeneity environment where the workload is decreased significantly and the utilization of computa-tional resources in increased obviously.
Amad Abdelkarim Mohamed Elmarghani, (04-2018), United Arab Emirates: www.sciencepubco.com/index.php/IJET, 7
Enhancing hadoop performance in homogeneous big data environment assuming configuration of dynamic slots in map reduce pattern
Journal ArticleHadoop is a Java-based programming framework that supports the storing and processing of large data sets in a distributed computing environment and it is very much appropriate for high volume of data. It uses HDFS for data storing and uses MapReduce for processing that data. MapReduce is a popular programming model to support data-intensive applications using shared-nothing clusters. The main objective of MapReduce programming model is to parallelize the job execution across multiple nodes for execution. Nowadays, all focus of the researchers and companies toward to Hadoop. Due to this, many scheduling algorithms have been proposed in the past decades. There are three important scheduling issues in MapReduce such as locality, synchronization and fairness. The most common objective of scheduling algorithms is to minimize the completion time of a parallel application and also achieve to these issues. Performance issues are introduced for Hadoop schedulers, and comparative performance analysis between different cases of jobs submission. These jobs are processed in different homogenous data environment and, under fixed or reconfigurable slot between map and reduce tasks for Hadoop MapReduce java programming clustering model. The results showed that when assigning tunable knob between map and reduce tasks under certain scheduler like FIFO algorithm, the performance enhanced 16.66% in inverted index, 55.55% in word count and 11.76% in classification process.
Amad Abdelkarim Mohamed Elmarghani, (04-2018), United Arab Emirates: International Journal of Engineering &Technology, 7
Evaluation of Milk Kinship Formation via Early Breast-Feeding
Journal ArticleConsanguinity constitutes one of the major health problems worldwide,
in which consanguineous marriages are associated with an increased risk for
congenital malformations and autosomal recessive diseases. Although the
advancement in modern biomedicine and forensic laboratories techniques continue
to guide scientists to move forward to unravel many life sciences secrets, it is still
ambiguous to investigate the full picture of milk kinship and its related
consanguinity. Theoretically, it is possible to see such consanguinity developed
from early sufficient breast-milk feeding. Thus, scientists should cooperate to
investigate the problem practically to find a proper solution. This review article
focuses on the alleged consanguinity that evolves from milk breastfeeding or
beyond through wet nursing or milk formula feeding. Additionally, this article
proposes the idea of removing milk genetic components to establish a new safe
genetically free formula as a promising solution.
Amad Abdelkarim Mohamed Elmarghani, (01-2018), United Arab Emirates: Saudi Journal of Medical and Pharmaceutical Sciences, 4
Revitalizing Phage Therapy in Combating Multi-Drug Resistant Bacteria
Master ThesisBacterial infections are one of the most dangerous infections that threaten the existence and continuity of life.
Despite the discovery and manufacturing of effective antibiotics to tackle these menaces, bacteria have developed
resistance against such treatments and transformed into new mutant resistant strains. Bacteriophages, or phages, are
regarded as effective alternative antibacterial agents. Recently, scientists have been taking a closer look at the variety of
different phages that attack bacteria. This review primarily focuses on the potential of phage therapy as an alternative
treatment to overcome a wide spectrum of resistant bacterial infections, as well as current phage therapy advancement. It
also proposes the idea of engineering “broad-spectrum phage” to overcome a wide range of resistant bacterial infections,
and its advantages over antibiotics, individual phage, and phage cocktails.
Amad Abdelkarim Mohamed Elmarghani, (09-2017), United Arab Emirates: Haya: The Saudi Journal of Life Sciences,
Acute mercury toxicity modulates cytochrome P450, soluble epoxide hydrolase and their associated arachidonic acid metabolites in C57Bl/6 mouse heart
Journal ArticleMercury exposure is associated with increased risk of cardiovascular disease and profound cardiotoxicity. However, the correlation between Hg(2+)-mediated toxicity and alteration in cardiac cytochrome P450s (Cyp) and their dependent arachidonic acid metabolites has never been investigated. Therefore, we investigated the effect of acute mercury toxicity on the expression of Cyp-epoxygenases and Cyp-ω-hydroxylases and their associated arachidonic acid metabolites in mice hearts. In addition, we examined the expression and activity of soluble epoxide hydrolase (sEH) as a key player in arachidonic acid metabolism pathway. Mercury toxicity was induced by a single intraperitoneal injection (IP) of 2.5 mg/kg of mercuric chloride (HgCl₂). Our results showed that mercury treatment caused a significant induction of the cardiac hypertrophy markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP); in addition to Cyp1a1, Cyp1b1, Cyp2b9, Cyp2b10, Cyp2b19, Cyp2c29, Cyp2c38, Cyp4a10, Cyp4a12, Cyp4a14, Cyp4f13, Cyp4f15, Cyp4f16 and Cyp4f18 gene expression. Moreover, Hg(2+) significantly increased sEH protein expression and activity levels in hearts of mercury-treated mice, with a consequent decrease in 14,15-, and 11,12-epoxyeicosatrienoic acids (EETs) levels. Whereas the formation of 14,15-, 11,12-, 8,9-dihydroxyeicosatrienoic acids (DHETs) was significantly increased. In conclusion, acute Hg(2+) toxicity modulates the expression of several Cyp and sEH enzymes with a consequent decrease in the cardioprotective EETs which could represent a novel mechanism by which mercury causes progressive cardiotoxicity. Furthermore, inhibiting sEH might represent a novel therapeutic approach to prevent Hg(2+)-induced hypertrophy.
Issa Emhemmed Alemyani Amara, (04-2014), Toxicology Letters: Elsevier, 219
.Modulation of cytochrome P450 1 (Cyp1) by vanadium in hepatic tissue and isolated hepatocyte of C57BL/6 mice
Journal ArticleThe objective of the current study was to investigate the effect of vanadium (V(5+)) on Cyp1 expression and activity in C57BL/6 mice liver and isolated hepatocytes. For this purpose, C57BL6 mice were injected intraperitoneally with V(5+) (5 mg/kg) in the absence and presence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (15 μg/kg) for 6 and 24 h. Furthermore, isolated hepatocytes from C57BL6 mice were treated with V(5+) (5, 10, and 20 μM) in the absence and presence of TCDD (1 nM) for 3, 6, 12, and 24 h. In vivo, V(5+) alone did not significantly alter Cyp1a1, Cyp1a2, or Cyp1b1 mRNA, protein, or catalytic activity levels. Upon co-exposure to V(5+) and TCDD, V(5+) significantly potentiated the TCDD-mediated induction of the Cyp1a1, Cyp1a2, and Cyp1b1 mRNA, protein, and catalytic activity levels at 24 h. In vitro, V(5+) decreased the TCDD-mediated induction of Cyp1a1 mRNA, protein, and catalytic activity levels. Furthermore, V(5+) significantly inhibited the TCDD-induced AhR-dependent luciferase activity. V(5+) also increased serum hemoglobin (Hb) levels in animals treated for 24 h. Upon treatment of isolated hepatocytes with Hb alone or in the presence of TCDD, there was an increase in the AhR-dependent luciferase activity. When isolated hepatocytes were treated for 2 h with V(5+) in the presence of TCDD, followed by replacement of the medium with new medium containing Hb, there was further potentiation to the TCDD-mediated effect. The present study demonstrates that there is a differential modulation of Cyp1a1 by V(5+) in C57BL/6 mice livers and isolated hepatocytes and demonstrates Hb as an in vivo specific modulator.
Issa Emhemmed Alemyani Amara, (08-2013), Archives of Toxicology: SPRINGER LINK, 87
Posttranslational mechanisms modulating the expression of the cytochrome P450 1A1 gene by methylmercury in HepG2 cells: a role of heme oxygenase-1
Journal ArticleRecently we demonstrated the ability of mercuric chloride (Hg(2+)) in human hepatoma HepG2 cells to significantly decrease the TCDD-mediated induction of Cytochrome P450 1A1 (CYP1A1) mRNA, protein, and catalytic activity levels. In this study we investigated the effect of methylmercury (MeHg) on CYP1A1 in HepG2 cells. For this purpose, cells were co-exposed to MeHg and TCDD and the expression of CYP1A1 mRNA, protein, and catalytic activity levels were determined. Our results showed that MeHg did not alter the TCDD-mediated induction of CYP1A1 mRNA, or protein levels; however it was able to significantly decrease CYP1A1 catalytic activity levels in a concentration-dependent manner. Importantly, this inhibition was specific to CYP1A1and was not radiated to other aryl hydrocarbon receptor (AhR)-regulated genes, as MeHg induced NAD(P)H:quinone oxidoreductase 1 mRNA and protein levels. Mechanistically, the inhibitory effect of MeHg on the induction of CYP1A1 coincided with an increase in heme oxygenase-1 (HO-1) mRNA levels. Furthermore, the inhibition of HO-1 activity, by tin mesoporphyrin, caused a complete restoration of MeHg-mediated inhibition of CYP1A1 activity, induced by TCDD. In addition, transfection of HepG2 cells with siRNA targeting the human HO-1 gene reversed the MeHg-mediated inhibition of TCDD-induced CYP1A1. In conclusion, this study demonstrated that MeHg inhibited the TCDD-mediated induction of CYP1A1 through a posttranslational mechanism and confirms the role of HO-1 in a MeHg-mediated effect.
Issa Emhemmed Alemyani Amara, (06-2013), Toxicology Letters: Elsevier, 219
Differential modulation of cytochrome P450 1a1 by arsenite in vivo and in vitro in C57BL/6 mice
Journal ArticleHeavy metals, typified by arsenite (As(III)), have been implicated in altering the carcinogenicity of aryl hydrocarbon receptor (AhR) ligands, typified by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), by modulating the induction of the Cyp1a1 enzyme, but the mechanism remains unresolved. In this study, the effects of As(III) on Cyp1a1 expression and activity were investigated in C57BL/6 mouse livers and isolated hepatocytes. For this purpose, C57BL/6 mice were injected intraperitoneally with As(III) (12.5 mg/kg) in the absence and presence of TCDD (15 μg/kg) for 6 and 24 h. Furthermore, isolated hepatocytes from C57BL/6 mice were treated with As(III) (1, 5, and 10 μM) in the absence and presence of TCDD (1 nM) for 3, 6, 12, and 24 h. At the in vivo level, As(III) decreased the TCDD-mediated induction of Cyp1a1 mRNA at 6h while potentiating its mRNA, protein, and catalytic activity levels at 24 h. At the in vitro level, As(III) decreased the TCDD-mediated induction of Cyp1a1 mRNA in a concentration- and time-dependent manner. Moreover, As(III) decreased the TCDD-mediated induction of Cyp1a1 protein and catalytic activity levels at 24 h. Interestingly, As(III) increased the serum hemoglobin (Hb) levels in animals treated for 24 h. Upon treatment of isolated hepatocytes with Hb alone, there was an increase in the nuclear accumulation of AhR and AhR-dependent luciferase activity. Furthermore, Hb potentiated the TCDD-induced AhR-dependent luciferase activity. Importantly, when isolated hepatocytes were treated for 5h with As(III) in the presence of TCDD and the medium was then replaced with new medium containing Hb, there was potentiation of the TCDD-mediated effect. Taken together, these results demonstrate for the first time that there is a differential modulation of the TCDD-mediated induction of Cyp1a1 by As(III) in C57BL/6 mouse livers and isolated hepatocytes. Thus, this study implicates Hb as an in vivo-specific modulator.
Issa Emhemmed Alemyani Amara, (05-2013), Free Radical Biology and Medicine: Elsevier, 58
Mercury modulates the cytochrome P450 1a1, 1a2 and 1b1 in C57BL/6J mice: in vivo and in vitro studies, Toxicol
Journal ArticleIn the current study C57BL/6J mice were injected intraperitoneally with Hg(2+) in the absence and presence of TCDD. After 6 and 24h the liver was harvested and the expression of Cyps was determined. In vitro, isolated hepatocytes were incubated with TCDD in the presence and absence of Hg(2+). At the in vivo level, Hg(2+) significantly decreased the TCDD-mediated induction of Cyps at 6h while potentiating their levels at 24h. In vitro, Hg(2+) significantly inhibited the TCDD-mediated induction of Cyp1a1 in a concentration- and time-dependent manner. Interestingly, Hg(2+) increased the serum hemoglobin (Hb) levels in mice treated for 24h. Upon treatment of isolated hepatocytes with Hb alone, there was an increase in the AhR-dependent luciferase activity with a subsequent increase in Cyp1a1 protein and catalytic activity levels. Importantly, when hepatocytes were treated for 2h with Hg(2+) in the presence of TCDD, then the medium was replaced with new medium containing Hb, there was potentiation of the TCDD-mediated effect. In addition, Hg(2+) increased heme oxygenase-1 (HO-1) mRNA, which coincided with a decrease in the Cyp1a1 activity level. When the competitive HO-1 inhibitor, tin mesoporphyrin was applied to the hepatocytes there was a partial restoration of Hg(2+)-mediated inhibition of Cyp1a1 activity. In conclusion, we demonstrate for the first time that there is a differential modulation of the TCDD-mediated induction of Cyp1a1 by Hg(2+) in C57BL/6J mice livers and isolated hepatocytes. Moreover, this study implicates Hb as an in vivo specific modulator of Cyp1 family.
Issa Emhemmed Alemyani Amara, (02-2013), Toxicology and Applied Pharmacology: Elsevier, 266
Effect of Mercury on AhR-regulated genes in C57Bl/6 Mice at Different Extrahepatic Tissues
Journal ArticleThe individual toxic effects of aryl hydrocarbon receptors (AhR) ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or heavy metals typified by mercury (Hg(2+)) has been previously demonstrated. However, little is known about the combined toxic effects of TCDD and Hg(2+)in vivo. Therefore, we examined the effect of exposure to Hg(2+) (2.5mg/kg) in the absence and presence of TCDD (15 μg/kg) on the AhR-regulated genes using C57Bl/6 mice. Hg(2+) alone did not affect kidney, lung, or heart Cyp1a1/1a2/1b1 mRNA levels. On the contrary, Hg(2+) alone significantly induced kidney Cyp1a1/1a2/1b1 and lung Cyp1b1 protein and catalytic activities. Hg(2+) also induced Nqo1, Gsta1, and HO-1 at the mRNA, protein, and activity levels in the kidney and heart but not in the lung. Upon co-exposure to Hg(2+) and TCDD, Hg(2+) significantly potentiated the TCDD-mediated induction of kidney and lung Cyp1a1/1a2/1b1 mRNA levels, while it decreased their kidney protein and catalytic activity and it increased their lung protein. In addition, Hg(2+) potentiated the TCDD-mediated induction of Nqo1, Gsta1, and HO-1 at mRNA, protein and activity levels in all tissues. The present study demonstrates that Hg(2+) modulates the constitutive and TCDD-induced AhR-regulated genes in a time-, tissue- and, AhR-regulated enzyme genes manner.
Issa Emhemmed Alemyani Amara, (07-2012), Food and Chemical Toxicology: Elsevier, 50