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Search Results: 1 - 10 of 713704 matches for " M. A. "
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Study on Parasexual Recombination between Pyricularia oryzae and Pyricularia grisea  [PDF]
M. A. Monsur, M. Kusaba
Agricultural Sciences (AS) , 2018, DOI: 10.4236/as.2018.93023
Abstract: Rice blast fungus is notorious for changeability in pathogenicity, but it lacks sexual life cycle. It can be postulated that such an imperfect fungus has another mechanism for generating genetic variations. Recent studies concerning comparative genomics reveal that parasexual recombination may play important role in the evolution of rice blast fungus. To observe the parasexualism of rice blast (Pyricularia oryzae) and crabgrass blast (Pyricularia grisea) fungus double inoculation and punch method were applied in this experiment. A total of 520 isolates collected from the double inoculated lesions was subjected to PCR-RFLP analysis of the ITS region to identify subcultures of the inoculated rice blast isolates. As a result, four isolates from the three double inoculated lesions with SA13-1ME and TP106 were identified as subcultures of TP106. To access the recombination genotypes, a total of 17 isolates from the three lesions was subjected to MAGGY-DNA fingerprint analysis. However, recombinant DNA fingerprint patterns between TP106 and SA13-1ME were not detected among the 17 isolates. Although TP022 was not recovered from the double inoculated lesions, the fact that TP106 was recovered from the double inoculated lesion indicates that rice blast fungus can invade and colonized in blast lesion on crabgrass. The opportunistic infection on the double inoculated lesions observed in this study potentially provides new insight into the life cycle of rice blast pathogen.
Economic Valuation of Sea Level Rise Impacts on Agricultural Sector: Damietta Governorate, Egypt  [PDF]
M. A. Abdrabo, M. A. Hassaan
Journal of Environmental Protection (JEP) , 2014, DOI: 10.4236/jep.2014.52012

The Nile Delta is considered to be one of the most vulnerable river deltas to Sea Level Rise (SLR) in the world. SLR is expected to affect large agricultural areas of the Nile Delta, either through inundation or higher levels and salinity of groundwater. It could be argued that such impacts would augment the problems experienced already in the area in terms of high groundwater table and salinity levels. In order to guide policy and decision making, especially in terms of assessing the economics of various adaptation options, there is a need to provide estimates of potential economic damage that could result from such changes. The paper in hand aims to estimate the economic value of potential primary impacts of higher levels of groundwater table due to expected SLR on agriculture productivity in Damietta Governorate as one of the Nile Delta coastal governorates. To conduct such an assessment, relationship between groundwater table level and agricultural productivity was first investigated in relevant literature. This was followed by reviewing prevailing conditions in the agricultural sector in the study area. Thereafter, a regression analysis for the main crops in the study area, between crop yield and groundwater table levels, was conducted. Based on the developed regression, a GIS (Geographic Information System)-based hydrological model, and a production economic model, were employed to assess economic value of higher levels of groundwater table impacts on agriculture productivity. It was found that future accumulative crop yield loss was estimated, using segmented linear regression, up to the year 2100 to be as much as L.E. 6.43 billion. It is worth mentioning that these

Contribution of Animal Agriculture to Greenhouse Gases Production in Swaziland  [PDF]
A. M. Dlamini, M. A. Dube
American Journal of Climate Change (AJCC) , 2014, DOI: 10.4236/ajcc.2014.33024
Abstract: The economy of Swaziland is depended on agriculture. In 2009, it was reported that agriculture, forestry, and manufacturing contributed 42% of Swaziland’s Gross Domestic Product (GDP). Besides economic importance, animal agriculture is important for food production and life sustenance. It is also viewed as a symbol of wealth and high social status particularly for the rural folks. Despite the merits of agricultural activities, agricultural production, particularly animal production, has been incriminated for an accelerated emission of greenhouse gases. These gases are responsible for global warming and climate change. The aim of this study was to determine the contribution of animal agriculture to greenhouse gases production and to elicit adaptation strategies to climate change and the role of modern technologies as mitigating measures. The minor and major greenhouse gases produced by farm animals were computed using the IPCC spread sheet for calculation of greenhouse gases emissions. The minor greenhouse gases produced by farm animals were NOx and CO2 and the major gasses included CH4 and N2O. The greenhouse gas that was emitted the most by farm animals was CH4, 24 Gg or 600 CO2e per annum. Ruminants were the major producers of methane. The producers of the least greenhouse gases emissions were non ruminants. Livestock produced 0.87 Gg of N2O per annum, a global warming potential of 259 CO2e. Feeding ammoniated straw and silage inoculating with transgenic rumen bacteria, animal breeding and manure storage techniques, use of biogas digester with methane gas recovery and emphasis on non ruminant production were possible strategies that could be employed to reduce greenhouse gases production from the livestock sector. It was recommended that feed preservation technologies, selection strategies, water harvesting, storage and recycling strategies and intensive livestock production systems could be used as adaptation strategies to climate change in livestock production.
Diagnostic Study of Nickel Plasma Produced by Fundamental (1064 nm) and Second Harmonics (532 nm) of an Nd: YAG Laser  [PDF]
M. Hanif, M. Salik, M. A. Baig
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.330203
Abstract: In the present work, we have studied the spatial evolution of the nickel alloy plasma produced by the fundamental (1064 nm) and second (532 nm) harmonics of a Q-switched Nd: YAG laser by placing the target material in air at atmospheric pressure. The four Ni I lines at 335.10 nm, 394.61 nm, 481.19 nm and 515.57 nm are used for the determination of electron temperature (Te) using Boltzmann plot method. The electron temperature is calculated as a function of distance from the target surface for both modes of Nd: YAG laser. In case of fundamental (1064 nm) mode of laser, the temperature varies from 13700 - 10270 K as the distance is varied from 0 to 2 mm. Whereas, in the case of second (532 nm) mode of laser it varies from 13270 - 9660 K for the same distance variation. The electron temperature has also been determined by varying the energy of the laser from 90 to 116 mJ, for the fundamental (1064 nm) harmonic and from 58 to 79 mJ for the second (532 nm) harmonics of the laser. The temperature increases from 14192 to 15765 K in the first case and from 13170 to 14800 K for the second case. We have also studied the spatial behavior of the electron number density in the plasma plume. The electron number density (Ne) in the case of fundamental (1064 nm) harmonic of the laser having pulse energy 125 mJ varies from 2.81 × 1016 to 9.81 × 1015 cm-3 at distances of 0 mm to 2.0 mm, whereas, in the case of second (532 nm) harmonic, with pulse energy 75 mJ it varies from 3.67 × 1016 to 1.48 × 1016 cm-3 for the same distance variation by taking Ni I line at 227.20 nm in both the cases.
Determination of the Metastable Zone Width, Nucleation Kinetics, Structural and Optical Properties of KCl Doped KAP Crystal  [PDF]
M. A. Rahman, M. M. Rahman
Journal of Crystallization Process and Technology (JCPT) , 2015, DOI: 10.4236/jcpt.2015.52005
Abstract: Slow evaporation method was used to grow pure and KCl (10 mol%) doped KAP single crystal. The solubility and metastable zone width of aqueous solutions of pure and KCl (10 mol%) doped KAP crystal were evaluated to analyze the crystallization process. Measuring the induction period τ, the critical nucleation parameters like interfacial energy (σ), energy of formation of the critical nucleus (ΔG*) were determined using the classical theory of nucleation. The structural properties and optical constants of the grown crystals have been put to test and observed that the addition of KCl results in an enhancement of properties of the crystal. Grown crystals were characterized by powder X-ray diffraction. FTIR spectra confirmed the presence of KCl in pure KAP crystal. UV- Visible spectroscopic studies revealed that addition of KCl in pure KAP crystal increased transparency from 75% to 80%. The analysis of the optical absorption data revealed the presence of both indirect and direct transitions and both of these band gaps increased with the addition of KCl. The transmittance data was analyzed to calculate the refractive index, oscillator energy, dispersion energy, electric susceptibility, zero-frequency dielectric constant and both the real and imaginary parts of the dielectric permittivity as a function of photon energy. The moments of ε(E) were also determined. The dispersion i.e. spectral dependence of the refractive index was discussed according to the single-effective oscillator model proposed by Wemple and DiDomenico.
An Integral Collocation Approach Based on Legendre Polynomials for Solving Riccati, Logistic and Delay Differential Equations  [PDF]
M. M. Khader, A. M. S. Mahdy, M. M. Shehata
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.515228

In this paper, we propose and analyze some schemes of the integral collocation formulation based on Legendre polynomials. We implement these formulae to solve numerically Riccati, Logistic and delay differential equations with variable coefficients. The properties of the Legendre polynomials are used to reduce the proposed problems to the solution of non-linear system of algebraic equations using Newton iteration method. We give numerical results to satisfy the accuracy and the applicability of the proposed schemes.

Efficiency Evaluation of Continuously Variable Transmissions Including a Planetary Gear Train  [PDF]
A. A?tTaleb, A. Chaaba, M. Sallaou
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.52015

With their advantages, continuously variable transmissions have gained more popularity in the last decade by their use in mechanical transmission systems. The present paper aims to analysis the efficiency of the transmission based on the mechanical efficiency of the planetary gear train integrated in such transmission. In this analysis, we consider the mechanical efficiency of the transmission has been determined considering how the efficiency of the CVT members changes as a function of the operating conditions. The efficiency of the planetary gear train as a function of the configuration, speeds in his three input/output shafts, and also with respect to the power flow type. Results are compared with those obtained from other methods performance evaluation of the transmission, available in the literature.

Heavy Metals in Soils around the Cement Factory inRockfort, Kingston, Jamaica  [PDF]
A. Mandal, M. Voutchkov
International Journal of Geosciences (IJG) , 2011, DOI: 10.4236/ijg.2011.21005
Abstract: This study deals with the distribution of heavy metals in soils around one of the most important industries in Kingston, Jamaica i.e. the Carib Cement factory at Rockfort. The dust emitted from the Caribbean Cement Company Limited (Carib Cement), located in Rockfort, Kingston, gets deposited in course of time over the soil, leaves and forms a grey cover on the surrounding soils. Geochemical analysis of the top soil, collected from the present study area has been undertaken to assess the impact of the dust emitted from the cement factory and its effect on the surrounding ecosystem. A total of seventeen top soil samples of 0-10 cm depth were collected from the close vicinity of the Rockfort and the Harbour view area and analysed by INAA, AAS, XRF for major, minor and trace elements. Results show that the top soils of the study area are enriched in Pb, Zn, Cr, Cd, V, Pb, and Hg which are released into the air from the cement kilns. Results show that the soils are enriched in Ca with a maximum value of 18% followed by Al, Fe and Na. Heavy metals in the soils of the study area shows relatively high concentrations of zinc with a maximum of 132 ppm followed by Cr (57) ppm and Pb (32) ppm. Maximum concentrations were found in soils sampled at a distance of 2-3 m from the cement factory as opposed to samples collected much further ie from the Harbour View area. High concentrations of the heavy metals in the soils near the cement factory as opposed to those further away can be due to the emissions from the factory. A significant contribution can also come from traffic emissions as the study area is located along one of the busiest street of Kingston, Jamaica.
A New Numerical Method for Solving the Stokes Problem Using Quadratic Programming  [PDF]
M. Baymani, A. Kerayechian
Intelligent Information Management (IIM) , 2010, DOI: 10.4236/iim.2012.23023
Abstract: In this paper we present a new method for solving the Stokes problem which is a constrained optimization method. The new method is simpler and requires less computation than the existing methods. In this method we transform the Stokes problem into a quadratic programming problem and by solving it, the velocity and the pressure are obtained.
Mechanisms of the Plurality of Scorpaena Porcus L. Serum Albumin  [PDF]
A. M. Andreeva
Open Journal of Marine Science (OJMS) , 2011, DOI: 10.4236/ojms.2011.12003
Abstract: The proteins, which bind albuminspecific dye Evans blue, are revealed in the low-molecular protein fraction of the blood serum from Scorpaena porcus L. and identified as serum albumin. They were represented by three bands in 2D-SDS-PAAG. MALDI-TOF-analysis revealed the fundamental similarity of the mass spec-trum of the fragments of tryptic cleavage of proteins with molecular weight 73 and 76 kDa. The role of du-plications and intragenic reconstructions in the creation of the plurality of scorpaena albumins is discussed.
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