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Search Results: 1 - 10 of 875331 matches for " A. M. S. Mahdy "
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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.

Second Kind Shifted Chebyshev Polynomials for Solving the Model Nonlinear ODEs  [PDF]
Amr M. S. Mahdy, N. A. H. Mukhtar
American Journal of Computational Mathematics (AJCM) , 2017, DOI: 10.4236/ajcm.2017.74028
Abstract: In this paper, we build the integral collocation method by using the second shifted Chebyshev polynomials. The numerical method solving the model non-linear such as Riccati differential equation, Logistic differential equation and Multi-order ODEs. The properties of shifted Chebyshev polynomials of the second kind are presented. The finite difference method is used to solve this system of equations. Several numerical examples are provided to confirm the reliability and effectiveness of the proposed method.
Implementation of the Homotopy Perturbation Sumudu Transform Method for Solving Klein-Gordon Equation  [PDF]
Amr M. S. Mahdy, Adel S. Mohamed, Ahmad A. H. Mtawa
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.63056
Abstract: This paper extends the homotopy perturbation Sumudu transform method (HPSTM) to solve linear and nonlinear fractional Klein-Gordon equations. To illustrate the reliability of the method, some examples are presented. The convergence of the HPSTM solutions to the exact solutions is shown. As a novel application of homotopy perturbation sumudu transform method, the presented work showed some essential difference with existing similar application four classical examples also highlighted the significance of this work.
RETRACTED:Implementation of the Homotopy Perturbation Sumudu Transform Method for Solving Klein-Gordon Equation  [PDF]
Amr M. S. Mahdy, Adel S. Mohamed, Ahmad A. H. Mtawa
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.61014

Short Retraction Notice

The substantial portions of the text came from ABDOLAMIR KARBALAIE et al, \"Exact Solution of Time-Fractional Partial Differential Equations Using Sumudu Transform\".

This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. Aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.

Editor guiding this retraction: ?Prof. Chris Cannings? (EiC of AM)

The full retraction notice in PDF is preceding the original paper which is marked \"RETRACTED\".

Numerical Studies for Fractional-Order Logistic Differential Equation with Two Different Delays
N. H. Sweilam,M. M. Khader,A. M. S. Mahdy
Journal of Applied Mathematics , 2012, DOI: 10.1155/2012/764894
Abstract: A numerical method for solving the fractional-order logistic differential equation with two different delays (FOLE) is considered. The fractional derivative is described in the Caputo sense. The proposed method is based upon Chebyshev approximations. The properties of Chebyshev polynomials are utilized to reduce FOLE to a system of algebraic equations. Special attention is given to study the convergence and the error estimate of the presented method. Numerical illustrations are presented to demonstrate utility of the proposed method. Chaotic behavior is observed and the smallest fractional order for the chaotic behavior is obtained. Also, FOLE is studied using variational iteration method (VIM) and the fractional complex transform is introduced to convert fractional Logistic equation to its differential partner, so that its variational iteration algorithm can be simply constructed. Numerical experiment is presented to illustrate the validity and the great potential of both proposed techniques.
Prevalence of HLA-B27 in Patients with Ankylosing Spondylitis in Qatar
M. H. Abdelrahman,S. Mahdy,I. A. Khanjar,A. M. Siam,H. A. Malallah,S. A. Al-Emadi,H. A. Sarakbi,M. Hammoudeh
International Journal of Rheumatology , 2012, DOI: 10.1155/2012/860213
Abstract: Background and Objectives. The human leukocyte antigen HLA-B27 is a class 1 antigen of the major histocompatibility complex and is strongly associated with ankylosing spondylitis (AS). The purpose of the present study is to investigate the distribution of HLA-B27 in patients with AS of different ethnic groups in Qatar. Design and Setting. Study design was cross-sectional and the setting was rheumatology clinics of Hamad General Hospital in Qatar where most of ankylosing spondylitis patients are followed up. Patients and Methods. Patients with diagnosis of AS who met the New York modified criteria for AS were tested for HLA-B27. 119 patients were tested for HLA-B27: 66 Arabs, 52 Asians (Indians, Pakistanis, Bengalis, and Iranians), and one Western (Irish). Results. Of all the individuals, 82 were positive (69%) for HLA-B27. Among the Arabs, 49/66 were positive (74%). Among the Asians, 32/52 were positive (61%). Furthermore, Qatari patients (10 males and one female) 9 were positive (82%), 14/19 Jordanians/Palestinians were positive, and 9/10 (90%) Egyptians were positive. Among the Asians, 19/26 Indians were positive (73%), which was similar to the Arabs. Conclusion. HLA-B27 in our small group of Arabs is present in 74%. Comparison with other data will be presented in detail. 1. Introduction The human leukocyte antigen (HLA-B27) is a class I antigen of the major histocompatibility complex, and it is strongly associated with ankylosing spondylitis and other related spondyloarthropathies (SpAs). It is present in only 8% of the general population worldwide [1]. In the Middle East, lower figures were reported from Arab countries, that is, United Arab Emirates (UAE) 0.5%, Saudi Arabia 2.6%, Kuwait 4%, Iraq 2.1%, Lebanon 1.4%, Tunisia 3.2%, and Syria 1.4% [2–8]. On the other hand, a remarkably higher percentage was found in Yemeni population (17%) [9]. In AS patients, HLA-B27 is present in 80–95% worldwide [1]. The prevalence of HLA-B27 among AS patients in the Arab world is generally lower than the worldwide figure, ranging from 56 to 84%: 84% in Iraq, 56% in UAE, 67% in Saudi Arabia, 58.6% in Egypt, 60% in Syria, and 73.4% in Iran [5, 9–12]. The prevalence of HLA-B27 among healthy persons and patients with AS in Qatar is unknown. In this study we tested 119 of AS patients followed in rheumatology outpatient clinics of Hamad General Hospital in Qatar for the status of HLA-B27. This is the first study in Qatar to assess the prevalence of HLA-B27 among patients with AS who are residents of Qatar (locals and expatriates). 2. Patients and Methods One hundred
Genetic and phenotypic variation of some reproductive traits in Egyptian buffalo
M.A. Aziz, S.J. Schoeman, G.F. Jordaan, O.M. El-Chafie, A.T. Mahdy
South African Journal of Animal Science , 2001,
Abstract: The objectives of this study were to determine the effects of season, year of calving and parity on lactation period, calving interval, number of days open and dry period in Egyptian buffalo, and to estimate genetic and phenotypic parameters for these traits using a multi-trait animal model. Season of calving, year of calving and parity affected the traits studied. Heritability estimates for lactation period, calving interval, dry period and number of days open were 0.09, 0.07, 0.13 and 0.08 respectively and repeatability estimates were 0.27, 0.14, 0.27 and 0.19 respectively. Estimates of the permanent environmental component (c2) were low. Genetic correlations between these traits were low and positive, except for that between lactation period and dry period, which was negative. A similar pattern was observed for phenotypic correlations, but these were higher than those observed for genetic correlations. South African Journal of Animal Science, Vol 31, Issue 3, Oct – Dec (2001) pp.195-199 Key Words Buffalo, Calving interval, Days open, Dry period, Heritability
Coma Etiologies And Its One-Month Outcome Sina Hospital (Year 2000)
Togha M,Mahdy Zadeh E,Tahmasbi S
Tehran University Medical Journal , 2002,
Abstract: Defining the patient outcome and decision making about allocation of our limited fund and technology for comatose patients depends on our knowledge about frequency and outcome of various coma etiologies. We determined the various coma causes frequency and one-month outcome of non traumatic coma. . In addition the co existence of the primary neurologic signs with the one-month outcome of non traumatic coma was defined."nMethods and Materials: Our study is based on 130 comatose patients in a one-year study in Sina Hospital that consisted of 80 non traumatic and 50 traumatic patients."nResults: 74% of the cases were men and 26% were women. The most common etiology of coma was trauma (38.5%). The other common etiologies were cerebro vascular diseases (25.4%), cancer (10%) and hypoxia-ischemia (8.5%). The most common cause of coma in men was trauma (46.9%) while the vascular diseases were the most common etiology of coma in women (41.2%).In under 40 year patients trauma was the cause of coma in 57.5% of cases in respect to 28% in above 40 cases. On the other hand, vascular diseases and malignancies were the etiology of coma in 15% of under 40 year patients and 46.5% of above 40 year patients. Among traumatic etiologies of coma, subdural hematoma was the most frequent (40%). In our research none of patients who did not have one of pupillary, oculocephalic or motor reflexes in the 3rd and 7th day of the onset of coma had acceptable outcome after one month. With consideration of pupillary, corneal, oculocephalic and motor reflexes in combination, loss of at least two of them in the 3rd and 7th day accompanied with no acceptable outcome. On the other hand the presence of three or more reflexes in the 3rd and 7th day of coma was a good prognostic factor, with 80% and 88.9% chance of acceptable recovery respectively."nConclusion: According of the study, the best time for prediction of outcome in a comatose patient, is the third or seventh the day after the onset of coma. Also relay on combination of brain stem reflexes, gives us more acceptable result.
Some Factors Affecting the Production of Carotenoids by Rhodotorula glutinis var. glutinis  [PDF]
Amr A. El-Banna, Amal M. Abd El-Razek, Ahmed R. El-Mahdy
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.31011
Abstract: A new yeast strain isolated from pin cushion flower (Scabiosa atropurpura) in our laboratory was selected from 200 yeast isolates as carotenoids producer and identified as Rhodotorula glutinis var. glutinis. The selected isolate was grown in synthetic medium to study the effect of carbon to nitrogen ratio, sources of nitrogen and carbon, mineral salts and incubation temperature on carotenoids production. The results indicated the following optimal conditions: carbon to nitrogen ratio of 5, ammonium sulphate as nitrogen source, sucrose as carbon source, presence of zinc sulphate in the medium and cultivation temperature of 25?C. The studied factors affected the dry biomass as well as the proportion of carotenoids and consequently the colour of pellets of the yeast. The yeast strain was grown under the optimal conditions to study the changes occurring in the medium and the pellets during carotenoids production for 6 days. Carotenoids production started after the first day of incubation and most of the carotenoids content in the yeast cells was produced during stationary phase. The highest cellular (861 μg?g–1) and volumetric (1.9 mg?L–1) carotenoids content were ob- tained after 5 days of growth.
Simultaneous Repair of Para-Umbilical Hernia during Cesarean Section (CS): A Novel Approach  [PDF]
Eman A. Eltokhy, Ibtsam Shehta Harera, Loay M. Gertallah, Walid A. Mawla, Ahmed Mahmoud Abdou, Entsar R. Mahdy, Ahmed Embaby
Surgical Science (SS) , 2018, DOI: 10.4236/ss.2018.97028
Abstract: Background: Pregnant women that are complaining from paraumbilical hernia postpone its repair until they get birth. We hypothesized that it will be better to perform hernia repair of such type of hernia simultaneously during performing cesarean section (CS) which will help to decrease future morbidity re-operation, avoid complications and further skin incision. In this study we aimed to compare the value of performing para-umbilical hernia repair simultaneously during performing CS through the same skin incision with performing para-umbilical hernia repair simultaneously during performing CS through another infra- or supra-umbilical skin incision and performing para-umbilical hernia repair electively later on after healing of a CS skin incision in relation to clinical recovery and patient satisfaction. Patients and Methods: This is a prospective cohort study, where we included 45 pregnant female patients who will give birth by CS, and we have divided them into 3 groups: the first group of patients (A) included 15 patients that undergoing paraumbilical hernia repair by pre-peritoneal mesh insertion through CS incision, the second group of patients (B) in-cluded 15 patients that undergoing paraumbilical hernia repair by infra- or supra-umbilical incision during CS incision and the third group of patients (C) included 15 patients that undergoing paraumbilical hernia repair by infra- or supra-umbilical incision later on after healing of the CS wound. We have evaluated advantages of that novel approach e.g. operation time, severity of pain, peri-partum and post-operative complications, financial cost, duration of hospital stay, clinical recovery, mesh rejection, and patient satisfaction. Results: In group A there is shorter duration of hospital stay, no new skin incision (p < 0.001), low incidence of early complications like umbilical ischemia, wound infection, wound dehiscence, seroma, skin flaps ischemia (p = 0.027), low incidence of late complications like painful ugly scar and mesh rejection (p = 0.05). Group A showed the highest incidence of clinical recovery and patients’ satisfaction (p > 0.002). Conclusions: Performing para-umbilical hernia repair by insertion of a pre-peritoneal mesh simultaneously during performing CS through the same skin incision is the best method of management of para-umbilical hernia in pregnant woman.
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