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Search Results: 1 - 10 of 1462 matches for " Mazen Saleh "
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Evaluation of the Pathogen Detect System and Anthracene-Based Enzyme Substrates for the Detection and Differentiation of E. coli and Total Coliforms in Water Samples  [PDF]
Neville Hewage, Mazen Saleh
Journal of Water Resource and Protection (JWARP) , 2015, DOI: 10.4236/jwarp.2015.79056
Abstract: Indirect detection of Escherichia coli and total coliforms can be based on the enzymatic activities of β-glucuronidase (β-glu) and β-galactosidase (β-gal). These enzymes utilize the substrates anthracene-β-d-glucuronide and pyrene d-galactopyranoside, respectively. Substrate cleavage by the enzyme releases the soluble fluorescent molecules 2-hydroxyanthracene and 1-hydroxypyrene, which can then be detected by a fluorometer. The Pathogen Detect system is an automated portable unit that can measure fluorescent enzyme products. In this report, we investigated the utility of the Pathogen Detect system for potential automation of water quality monitoring. The PDS unit has the ability to detect E. coli, mean 14.7 h at a standard deviation of 1.5, when the sample mean is 9.1 cells in 100 mL with a standard deviation of 12.6. Similarly, total coliforms may be detected at mean 14.7 h with a standard deviation of 1.4 when the sample mean is 59.6 cells in 100 mL, with a standard deviation of 144.5. The PDS unit has the ability to detect single cells of either total coliforms or E. coli in 100 mL water sample within 18 hours. Turbidity and color of water samples have no impact on the detection of E. coli and total coliforms.
Cyanobacteria Diversity in Blooms from the Greater Sudbury Area  [PDF]
Suzanne Evans, Mazen Saleh
Journal of Water Resource and Protection (JWARP) , 2015, DOI: 10.4236/jwarp.2015.711071
Abstract: The Greater Sudbury Area is approximately 400 km north of the city of Toronto and falls within a large number of temperate lakes of various sizes. This area has been mined for nickel and other metals for several decades. These activities have affected the watersheds of Northern Ontario and have influenced the chemistry of a number of lakes. Blooms of cyanobacteria occur yearly in several lakes, mainly in the early and late summer months. Much of the chemistry of these lakes is known but the nature of the cyanobacterial blooms and the factors that may contribute to their sudden appearance are not. We sampled blooms from five Greater Sudbury Area lakes and identified the species present by morphological and molecular methods. The dominant genera present as characterized by morphological examination were Synechocystis, Leptolyngbya, Anabaena, Cyl-indrospermum, Nostoc, Borzia, Phormidium, Pseudoanabaena, Oscillatoria, and Planktothrix. Three of these isolates, Leptolyngbya, Anabaena, and Planktothrix were confirmed by partial rRNA sequence analysis.
Naso Alveolar Cleft Reconstruction: Does Patients’ Age Play a Factor in Postoperative Complication Rate?  [PDF]
Almasri Mazen
Surgical Science (SS) , 2013, DOI: 10.4236/ss.2013.41016

Purpose: The purpose of this report is to compare the outcome of unilateral alveolar cleft reconstruction (ACR) in patients aged 6 - 8 years versus older more comprehending patients aged 9 - 12 years. Materials and Methods: A chart review (from March 2006 to June 2010) was conducted of patients who had alveolar cleft reconstruction using anterior iliac crest bone graft. All the cases included are non syndromic healthy patients whom had unilateral alveolar cleft and were operated for the first time. A total of 49 healthy patients were included in the study. Twenty-four had their surgery between the age of 6 and 8 (Group A), and twenty-five had theirs between 9 and 12 (Group B). The postoperative recovery and complications were compared between the two groups. Results: In group A, 16% (n = 4) showed minimal wound dehiscence while 8% (n = 2) had a minor wound infection due to food particles wedged in the wound. In Group B, 20% (n = 5) of the patients presented with minimal wound dehiscence, while 12% (n = 3) had minor wound infection due to food particles wedged in the wound. No significant difference was found between the two groups using Fishers exact test, two-tailed p-value >0.05. Conclusion: Age factor was not found to be a factor contributing to ACR complication rate.

Does Immediate Reconstruction of Postextraction Lost Buccal Plate Reduce the Chances of Implant Surface Exposure after Crown Placement?  [PDF]
Mazen Almasri
Surgical Science (SS) , 2013, DOI: 10.4236/ss.2013.41020

Objective: To investigate if immediate reconstruction of fresh extraction sockets lost buccal wall would reduce the possibilities of implant surface exposure and improve the treatment predictability. Materials and Methods: A retrospective chart review of Healthy patients harboring periodontally compromised anterior teeth that were planned for extraction and subsequent implant therapy were the target of our study. All the sockets included witnessed loss of the buccal bone plate. Seventy-two anterior sockets were grafted with xenogenic grafts to reconstruct such defects immediately after the extractions. 9 to 13 months later, the alveolar ridges were surgically exposed and implants were placed. Results: All the surgical sites did not show any labial plate thinning, dehiscence, or fenestration at the time of implant placement. Moreover, no gingival recession and implant metal show was noticed up to 39 months post crown placement. Conclusion: Immediate reconstructions of lost buccal plate in fresh extraction sockets reduces the chances of implant surface exposure up to two years post crown placement.

Selecting the Six Sigma Project: A Multi Data Envelopment Analysis Unified Scoring Framework  [PDF]
Mazen Arafah
American Journal of Operations Research (AJOR) , 2015, DOI: 10.4236/ajor.2015.53011
Abstract: The importance of the project selection phase in any six sigma initiative cannot be emphasized enough. The successfulness of the six sigma initiative is affected by successful project selection. Recently, Data Envelopment Analysis (DEA) has been proposed as a six sigma project selection tool. However, there exist a number of different DEA formulations which may affect the selection process and the wining project being selected. This work initially applies nine different DEA formulations to several case studies and concludes that different DEA formulations select different wining projects. Also in this work, a Multi-DEA Unified Scoring Framework is proposed to overcome this problem. This framework is applied to several case studies and proved to successfully select the six sigma project with the best performance. The framework is also successful in filtering out some of the projects that have “selective” excellent performance, i.e. projects with excellent performance in some of the DEA formulations and worse performance in others. It is also successful in selecting stable projects; these are projects that perform well in the majority of the DEA formulations, even if it has not been selected as a wining project by any of the DEA formulations.
Combining Lean Concepts & Tools with the DMAIC Framework to Improve Processes and Reduce Waste  [PDF]
Mazen Arafeh
American Journal of Operations Research (AJOR) , 2015, DOI: 10.4236/ajor.2015.53017
Abstract: Six Sigma DMAIC methodology has been applied to systematically apply lean manufacturing concepts and tools in order to improve productivity in a local company specialized in the manufacturing of safety and fire resistance metal doors, windows, and frames. In-depth analysis of the plant processes unfolded different critical processes, specifically foam injection process and sheet metal cutting process. Throughout the different project phases, various improvements had been implemented to reduce production cycle time from 216 min to 161 min; non-value added activities in the different processes were identified and eliminated. Plant layout and machine reconfiguration reduced backtracking and unutilized space. Percentage of defective doors (needing rework) dropped from 100% to only 15%. The successful implementation of this project is largely due to top management active involvement and participation of workers and operators in all stages of the project. Finally, new policies and mentoring programs are introduced to maintain improvements.
Leveraging Six Sigma Tools and Methodology to Improve Student English Language Performance at Elementary School  [PDF]
Mazen Arafeh
American Journal of Operations Research (AJOR) , 2016, DOI: 10.4236/ajor.2016.64026
Abstract: Purpose: The purpose of this paper is to discuss how the Six Sigma (SS) methodology can be used to improve the performance of students in English as a second language and enhance the teaching process by utilizing quality tools in an educational environment. Design/Methodology/Approach: The paper uses the different quality improvement tools within the Define, Measure, Analyze, Improve and Control (DMAIC) phases to improve student performance in an English language class at a private school. Findings: Quality tools, such as cause and effect diagrams and quality function deployment, have been successfully applied within the Six Sigma DMAIC framework in the educational sector to improve the performance of students and enhance the teaching process. Practical Implications: This paper helps school administrations to analyze student performance and implement improvement actions to improve their performance. Originality/Value: The principal objective of this paper is to demonstrate how quality improvement tools can be introduced and successfully applied in an elementary school to improve student performance and communication between the school administration, teachers and parents.
Synthesis and Characterization of Sb65Se35-xGex Alloys  [PDF]
Saleh Ahmed Saleh
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.27127
Abstract: Density, chemical, structural and vibrational studies of Sb65Se35-xGex system with 0 ≤ x ≤ 20 produce by melt-quench technique were carried out using Archimedes method, Energy Dispersive Spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy. All specimens are polycrystalline in nature as confirmed by XRD pattern. The compositional dependence of the XRD and Raman spectra suggests the presence of two basic structural units, SbSe3 pyramids with three-fold coordinated Sb atom at the apex and GeSe4 tetrahedrons. The compositional dependence of these physic Chemical properties of the investigated samples are investigated and discussed in light of many models. PACS: 68.55. Ln; 61.50. Ks; 68.55.Jk
Role of Prostate Specific Antigen (PSA) in Pathogenesis of Prostate Cancer  [PDF]
Saleh Altuwaijri
Journal of Cancer Therapy (JCT) , 2012, DOI: 10.4236/jct.2012.34043
Abstract: Prostate cancer (PCa) is most common diagnosed cancer in men and it is second most common cause of male cancer death. Many factors have been implicated in the pathogenesis of PCa. Although many papers have discussed the prostate specific antigen (PSA) as biomarker of PCa, very few have addressed its rule in the carcinogenesis, metastasis and invasion of PCa. In this article we will review the pathological role of PSA, as a potential target in the therapeutics of PCa.
French Firm’s Financing Choices: Towards a Reconciliation of the Static Trade-Off Theory and the Pecking Order Theory?
Gharsalli Mazen
International Journal of Financial Research , 2012, DOI: 10.5430/ijfr.v3n1p57
Abstract: The main purpose of this study is to examine the validity of the static trade-off theory and the pecking order theory using a French panel data. Our empirical tests provide that we can not formally reject either of the two theories explaining financing behavior. However, they confirm the importance of considerations provided by the static trade-off theory. On the contrary, when we combine the adjustment model and the pecking order model we find that the statistical power of the hierarchical model is improved and the choice of financing of French firms confirms the greatest explanatory power of the pecking order hypotheses.
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