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Search Results: 1 - 10 of 417176 matches for " Hayssam M. Ali "
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Growth, chemical composition and soil properties of Tipuana speciosa (Benth.) Kuntze seedlings irrigated with sewage effluent
Hayssam M. Ali,Mohamed H. Khamis,Fatma A. Hassan
Applied Water Science , 2012, DOI: 10.1007/s13201-012-0027-4
Abstract: This study was carried out at a greenhouse of Sabahia Horticulture Research Station, Alexandria, Egypt, to study the effect of sewage effluent on the growth and chemical composition of Tipuana speciosa (Benth.) Kuntze seedlings as well as on soil properties for three stages. The irrigation treatments were primary-treated wastewater and secondary-treated wastewater, in addition to tap water as control. Therefore, the treated wastewater was taken from oxidation ponds of New Borg El-Arab City. Results of these study revealed that the primary effluent treatment explored the highest significant values for vegetative growth and biomass, compared to the other treatments. In addition, the higher significant concentration and uptake of chemical composition in different plant parts were obtained from the primary effluent treatment during the three stages of irrigation. It was found that the concentration of heavy metals in either plant or soil was below as compared to the world-recommended levels. These findings suggested that the use of sewage effluent in irrigating T. speciosa seedlings grown in calcareous soil was beneficial for the improvement of soil properties and production of timber trees, and also important for the safe manner of disposal of wastewater.
Effect of Calcium and Potassium on Antioxidant System of Vicia faba L. Under Cadmium Stress
Manzer H. Siddiqui,Mohamed H. Al-Whaibi,Ahmed M. Sakran,Mohammed O. Basalah,Hayssam M. Ali
International Journal of Molecular Sciences , 2012, DOI: 10.3390/ijms13066604
Abstract: Cadmium (Cd) in soil poses a major threat to plant growth and productivity. In the present experiment, we studied the effect of calcium (Ca 2+) and/or potassium (K +) on the antioxidant system, accumulation of proline (Pro), malondialdehyde (MDA), and content of photosynthetic pigments, cadmium (Cd) and nutrients, i.e., Ca 2+ and K + in leaf of Vicia faba L. (cv. TARA) under Cd stress. Plants grown in the presence of Cd exhibited reduced growth traits [root length (RL) plant ?1, shoot length (SL) plant ?1, root fresh weight (RFW) plant ?1, shoot fresh weight (SFW) plant ?1, root dry weight (RDW) plant ?1 and shoot dry weight (SDW) plant ?1] and concentration of Ca 2+, K +, Chlorophyll (Chl) a and Chl b content, except content of MDA, Cd and (Pro). The antioxidant enzymes [peroxidase (POD) and superoxide dismutase (SOD)] slightly increased as compared to control under Cd stress. However, a significant improvement was observed in all growth traits and content of Ca 2+, K +, Chl a, Chl b ,Pro and activity of antioxidant enzymes catalase (CAT), POD and SOD in plants subjected to Ca 2+ and/or K +. The maximum alleviating effect was recorded in the plants grown in medium containing Ca 2+ and K + together. This study indicates that the application of Ca 2+ and/or K + had a significant and synergistic effect on plant growth. Also, application of Ca 2+ and/or K + was highly effective against the toxicity of Cd by improving activity of antioxidant enzymes and solute that led to the enhanced plant growth of faba bean plants.
Machine learning for metagenomics: methods and tools
Hayssam Soueidan,Macha Nikolski
Quantitative Biology , 2015,
Abstract: While genomics is the research field relative to the study of the genome of any organism, metagenomics is the term for the research that focuses on many genomes at the same time, as typical in some sections of environmental study. Metagenomics recognizes the need to develop computational methods that enable understanding the genetic composition and activities of communities of species so complex that they can only be sampled, never completely characterized. Machine learning currently offers some of the most computationally efficient tools for building predictive models for classification of biological data. Various biological applications cover the entire spectrum of machine learning problems including supervised learning, unsupervised learning (or clustering), and model construction. Moreover, most of biological data -- and this is the case for metagenomics -- are both unbalanced and heterogeneous, thus meeting the current challenges of machine learning in the era of Big Data. The goal of this revue is to examine the contribution of machine learning techniques for metagenomics, that is answer the question "to what extent does machine learning contribute to the study of microbial communities and environmental samples?" We will first briefly introduce the scientific fundamentals of machine learning. In the following sections we will illustrate how these techniques are helpful in answering questions of metagenomic data analysis. We will describe a certain number of methods and tools to this end, though we will not cover them exhaustively. Finally, we will speculate on the possible future directions of this research.
Laplace Transform Method for Unsteady Thin Film Flow of a Second Grade Fluid through a Porous Medium  [PDF]
M. Ali, M. Awais
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.53017
Abstract:

In this article, we have effectively used the Numerical Inversion of Laplace transform to study the time-dependent thin film flow of a second grade fluid flowing down an inclined plane through a porous medium. The solution to the governing equation is obtained by using the standard Laplace transform. However, to transform the obtained solutions from Laplace space back to the original space, we have used the Numerical Inversion of Laplace transform. Graphical results have been presented to show the effects of different parameters involved and to show how the fluid flow evolves with time.

Optimal Convergence Analysis for Convection Dominated Diffusion Problems  [PDF]
M. A. Mohamed Ali
Journal of Applied Mathematics and Physics (JAMP) , 2013, DOI: 10.4236/jamp.2013.13004
Abstract:

In classical mixed finite element method, the choice of the finite element approximating spaces is restricted by the imposition of the LBB consistency condition. The method of H1-Galerkin mixed finite element method avoids completely the imposition of such a condition on the approximating spaces. In this article, we discuss and analyze error estimates for Convection-dominated diffusion problems using H1-Galerkin mixed finite element method, along with the method of characteristics. Optimal order of convergence has been achieved for the error estimates of a two-step Euler backward difference scheme.

Rock Slope Stability Problems in Wadi Quaz-Dam Site No. 2, Jeddah-Saudi Arabia  [PDF]
Ali Abdullah M. Alzahrani
World Journal of Engineering and Technology (WJET) , 2015, DOI: 10.4236/wjet.2015.34026
Abstract: The present investigation deals with the engineering geological studies of soil and rock masses in the Wadi Quaz area-Dam No. 2, East of Jeddah. Wadi Quaz area-Dam No. 2, East of Jeddah, Saudi Arabia often faces floods during rainy seasons, so it is so urgent to investigate the area before building any dam or preventing water from flow. Preventing water from flow will produce new dangerous factors such as uplift force which may cause the dam failure. To have a better understanding of the factors that may affect the slope stability, many rock slope locations are observed in detail to assess the effect of discontinuities formed in the rock masses. Fieldwork and Laboratory tests were carried out on soil and rocks. Soils included identification of soil type using unified soil classification system, permeability, water content and field density were done for soils. Rocks include identification of physical and mechanical properties such as: rock type, degree of weathering, rock strength, RQD, joint spacing measurements, and geometric properties (Dip, and Dip direction). Different methods were used to evaluate the potential failure in the studied area depending on rock mass rating and slope stability analysis. The well-known classification of rock masses titled Rock Mass Rating system [1] was used for categorizing the rock masses in the studied area besides slope mass rating [2] which would help to estimate the rock stability. The kinematical analysis was applied to investigate the potential failure mode which might occur in the dam abutments. This paper will provide the stability of dam abutments in both summer season and winter season besides general estimation of the seepage problems related to the soil and according to its permeability.
Some Structural Properties of Dynamically Drawn iPP Fibers  [PDF]
Afaf M. Ali
Optics and Photonics Journal (OPJ) , 2017, DOI: 10.4236/opj.2017.76011
Abstract: Changes in the different structural parameters of iPP fibers during the dynamically cold drawing process were characterized. Using the dynamic mechanical cold drawing device attached to Fizeau interference system all the optical and structural properties can be measured. With the aid of this device the effect of the strain rate on the different structure properties was measured. The molecular orientations, molecular polarizability, molar reflectivity and shrinkage stress were measured. Reorientation of the molecules led to a significant variations in the measured structure properties of the drawn iPP fibers during applying the external tension.
Heavy Metals in Lipstick Products Marketed in Saudi Arabia  [PDF]
Faten M. Ali Zainy
Journal of Cosmetics, Dermatological Sciences and Applications (JCDSA) , 2017, DOI: 10.4236/jcdsa.2017.74030
Abstract: The present study reports the content of 14 heavy metals (Al, Fe, Ti, Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) in twenty-two (n = 22) lipstick products of imported and locally manufactured at the local market in Jeddah, Saudi Arabia using Inductivity Coupled Plasma-Optical Emission Spectrophotometer (ICP-OES). The overall average contents of Al, Fe, Ti, Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn were 3131.18 ± 0.09, 9642.92 ± 0.079, 46.59 ± 0.109, 0.545 ± 0.009, 2.041 ± 0.024, 1371.439 ± 0.085, 0.134 ± 0.008, 4.242 ± 0.02, ND, 3.934 ± 0.03, 19.712 ± 0.012, 20.196 ± 0.056, 0.725 ± 0.012, and 858.666 ± 0.083 μg/g, respectively. The correction coefficient of the results is up to 0.9995, showing an excellent linear relationship between metal concentrations in samples. The results also revealed that, the total concentrations of toxic metals in various samples ranged from 1201.35 - 60,800.36 μg/g. The dark-colored lipstick samples 1B, 2B, 3B, 4B, 5B, 7B, B8, 9B, and 10B revealed high content of total toxic metals compared to the light-colored lipstick samples 1A, 2A, 3A, 4A, 4C, 5A, 7A, 8A, 9A, and 10A. The concentrations of Al, Fe, Ba, and Zn in the samples within each class under investigation are relatively high whereas the concentrations of Ag, As, Cd, Co, Cu, and Pb are lowest; and Ti, Mn, and Ni contents were below 100 μg/g. Chromium was not detected in any sample. Since no safe limits for most of these metals relating to cosmetic products are available in Saudi Arabia, it is hard to ascertain whether the values obtained in this study are relatively high or low. Prolonged use of products containing these elements may pose a threat to human health and could damage the environment.
On Cycle Related Graphs with Constant Metric Dimension  [PDF]
Murtaza Ali, Gohar Ali, Usman Ali, M. T. Rahim
Open Journal of Discrete Mathematics (OJDM) , 2012, DOI: 10.4236/ojdm.2012.21005
Abstract: If G is a connected graph, the distance d (u,v) between two vertices u,v ∈ V(G) is the length of a shortest path between them. Let W = {w1, w2, ..., wk} be an ordered set of vertices of G and let v be a vertex of G . The repre-sentation r(v|W) of v with respect to W is the k-tuple (d(v,w1), d(v,w2), …, d(v,wk)). . If distinct vertices of G have distinct representations with respect to W , then W is called a resolving set or locating set for G. A re-solving set of minimum cardinality is called a basis for G and this cardinality is the metric dimension of G , denoted by dim (G). A family ? of connected graphs is a family with constant metric dimension if dim (G) is finite and does not depend upon the choice of G in ?. In this paper, we show that dragon graph denoted by Tn,m and the graph obtained from prism denoted by 2Ck + {xkyk} have constant metric dimension.
Identification of conserved gene clusters in multiple genomes based on synteny and homology
Sarkar Anasua,Soueidan Hayssam,Nikolski Macha
BMC Bioinformatics , 2011, DOI: 10.1186/1471-2105-12-s9-s18
Abstract: Background Uncovering the relationship between the conserved chromosomal segments and the functional relatedness of elements within these segments is an important question in computational genomics. We build upon the series of works on gene teams and homology teams. Results Our primary contribution is a local sliding-window SYNS (SYNtenic teamS) algorithm that refines an existing family structure into orthologous sub-families by analyzing the neighborhoods around the members of a given family with a locally sliding window. The neighborhood analysis is done by computing conserved gene clusters. We evaluate our algorithm on the existing homologous families from the Genolevures database over five genomes of the Hemyascomycete phylum. Conclusions The result is an efficient algorithm that works on multiple genomes, considers paralogous copies of genes and is able to uncover orthologous clusters even in distant genomes. Resulting orthologous clusters are comparable to those obtained by manual curation.
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