Low Cost Cloud-Assisted Peer to Peer Live Streaming

( Bahaa Aldeen Alghazawy ),( Satoshi Fujita ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.4

Recently, Peer-to-Peer (P2P) live streaming assisted by the cloud computing has attracted considerable attention to improve the reliability of the P2P such as the resilience to peer churn and the shortage of upload capacity. The cost of cloud-assistance is comprised of the number of requests issued to the cloud and the amount of data fetched from the cloud. In this paper, we propose three techniques to reduce the cost of such a cloud-assistance.More concretely, in the proposed method, 1) each peer which lost its parent in the overlay can find a new parent by referring to the information registered in the cloud, 2) several peers which proactively fetch chunks from the cloud are dynamically invested, and 3) the number of requests issued to the cloud is reduced by allowing peers to fetch a collection of chunks using a single request. The performance of the proposed method is evaluated by simulation. The simulation results indicate that it reduces the cost of conventional scheme by 46% while guaranteeing the quality of live streaming service.

Synthesis and Antimicrobial Activity of Some New 1-Alkyl-2-alkylthio-1,2,4-triazolobenzimidazole Derivatives

Bahaa Gamal Mohamed,Mostafa Ahmed Hussein,Abdel-Alim Mohamed Abdel-Alim,Mohammed Hashem 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.1

Some new derivatives of 1,2,4-triazolo[2,3-a]benzimidazoles were synthesized through the reaction of 1,2-diaminobenzimidazole with carbon disulfide. The resulting 1,2,4-triazolo-[2,3- a]benzimidazole-2-thione intermediate was reacted with one equivalent of alkyl halides to give the corresponding 2-alkylthio derivatives, which were further alkylated through the reaction with another one equivalent of different alkyl halides to afford the target compounds; 1-alkyl-2- alkylthio-1,2,4-traizolo[2,3-a]benzimidazoles. On the other hand, the 1,2-disubstituted derivatives with two identical alkyl substituents were prepared by the reaction of 1,2,4-triazolo[2,3- a]benzimidazole-2-thione with two equivalents of the alkyl halides. The structures of the new compounds were assigned by spectral and elemental methods of analyses. The synthesized compounds were tested for their antibacterial and antifungal activities. Most of the tested compounds proved comparable results with those of ampicillin and fluconazole reference drugs. The study indicated that, the antibacterial as well as the antifungal activities of the test compounds were improved with increase in the bulkiness of the introduced alkyl groups. Also, some active antibacterial compounds were tested for their antimycobacterial activity. All the test compounds showed equipotent antitubercular activity as that of INH as a reference drug.

Slide Session : OS-RES-11 ; Tetrahdrobiopterin(BH4): Novel Treatment for Pulmonary Hypertension

( Bahaa Francis ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Pulmonary Hypertension (PH) is characterized by pulmonary vasoconstriction, vascular remodeling, right heart failure and death. The pathogenesis is multifactorial. The integrity of the pulmonary vascular endothelium, particularly its endothelial nitric oxide synthase (eNOS), is a key factor in maintaining normal pulmonary vascular homeostasis. While enzymatically coupled, eNOS produces nitric oxide (NO), otherwise eNOS activation may lead to increased superoxide production. The cofactor tetrahydrobiopterin (BH4) is an important regulator of eNOS function; by ‘recoupling’ eNOS and enhancing its enzymatic activity, BH4 increases NO bioavailability and decreases superoxide production. Thus pharmacological supplementation with BH4 may be a novel treatment in PH. Methods: Isolated perfused lung studies were used to explore the acute pharmacological effects of BH4 in regulating pulmonary vascular tone. Animal studies were used to evaluate the pharmacological effects of BH4 treatment and to clarify its molecular mechanism using biochemical and histological experiments. Results: In acute ex-vivo studies, BH4 was found to regulate hypoxic pulmonary vasoconstriction. Its effects are mediated via enhancing NO and H2O2 secretion and its antioxidant properties, all leading to pulmonary vasodilation. Superoxide dismutase co-administration with BH4 enhanced its vasodilatory effect. In chronic studies, BH4 prevented the development of PH in monocrotaline model and ameliorated established PH when administered to recover the disease. BH4 partially reversed PH in hypoxia model. In both models, BH4 reduced pulmonary vascular muscularization and reversed right ventricular hypertrophy. BH4 effect was evidenced by enhancing the activity and protein levels of eNOS, recoupling eNOS activity to produce more NO, and its second messenger cGMP, and lowering the levels of superoxide. Conclusions: BH4 bioavailability is essential for maintaining pulmonary vascular homeostasis, and plays a major role in the pathophysiology of PH. This study establishes a fi rm basis to explore the therapeutic potential of BH4 in human PH.

An investigation on the N2O decomposition activity of MnxCo1 xCo2O4 nanorods prepared by the thermal decomposition of their oxalate precursors

Bahaa M. Abu-Zied,Lucie Obalová,Katerina Pacultová,Anna Klegova,Abdullah M. Asiri 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.93 No.-

This investigation aimed to develop a series of new spinel-oxide catalysts with the general formulaMnxCo1 xCo2O4 (0.0 x 1.0) and testing their activity towards N2O direct decomposition. Thesecatalysts have been prepared by the microwave-assisted co-precipitation method and the subsequentcalcination at 500 C. Characterization results revealed that the utilized preparation protocol has led tothe development of pure spinel phases with nanorods morphology. N2O decomposition experimentsindicated that the prepared catalysts were active and the best performance was exhibited byMn0.75Co0.25Co2O4 catalyst. The activity of the Mn0.75Co0.25Co2O4 was enhanced by doping with K-ions atoptimal concentration (nK/(nCo + nMn) = 0.025). The co-existence of some contaminants (O2, NO, H2Ovapor) in the reactor feed revealed different inhibitory levels on the performance of theK0.025Mn0.75Co0.25Co2O4 catalyst. The inhibitory order was O2< H2O < NO < O2 + H2O < O2 + H2O + NO.

Auto-detection of Spectral Notches of Head-related Transfer Function using Wavelet Multi-resolution Analysis

Bahaa Al-Sheikh,Mohammad Shukri Salman,Alaa Eleyan 대한전자공학회 2021 IEIE Transactions on Smart Processing & Computing Vol.10 No.5

The spectral features of pressure characterized by the human outer ear, head, and torso are vital for sound localization in humans, especially for sound above 5 kHz. Many studies have shown that spectral notches contribute significantly as cues for this purpose. These spectral notches and their center frequencies depend on the shape and geometry of each individual, so their characteristics are different between individuals. We used wavelet multi-resolution analysis to automatically detect the center frequencies of spectral notches in head-related transfer functions (HRTFs). Auto-detection of these notches at certain locations for an individual helps in using suitable, complete, 3D HRTFs from HRTF datasets that have similar notch characteristics for an individual. Symlet and Daubechies wavelets were successfully used at different decomposition levels for this purpose. Symlet2 gives the best performance in terms of the auto-detection sensitivity.

Genetic Studies of Response to Mature Embryo Culture and Relationship with Agro-Morphological Traits and Molecular Markers in Wheat

( Bahaa El-dein El-sayd Abd El-fatah ) 한국육종학회 2018 Plant Breeding and Biotechnology Vol.6 No.3

Five concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and three combinations of indole-3-acetic acid (IAA) and benzyl-amino purine (BA) were used to analyze response to mature-embryo culture for six genotypes of wheat (Triticum aestivum L.) The differences between genotypes as well as between the concentrations of hormones were significant for three tissue culture traits, namely callus formation (C.%), embryogenic calli (E.C.%) and plant regeneration per embryogenic callus (No. Sh/E.C.). Murashige and Skoog basal medium (MS) supplemented with 7 mg/L 2,4-D showed the highest percentage of callus formation while the highest percentage of embryogenic calli (% of E.C.) was obtained on MS medium supplemented with 4 mg/L 2,4-D. MS medium containing 0.1 mg/L IAA and 1 mg/L BA exhibited the highest number of plant regeneration (No. Sh/E.C.). A half diallel mating was designed to produce 15 crosses among six genotypes. Mean square of the diallel analysis of variance indicated highly significant differences among the parents and F1 hybrids for E.C.% and No. Sh/E.C. traits. The results revealed that Lin-6 (P4) was the best combiner for E.C.% and No. Sh/E.C. Estimates of narrow-sense heritability were 83.1% and 69.0% for E.C.% and No. Sh/E.C., respectively. The genetic diversity among six wheat genotypes was analyzed using three tissue culture traits, 10 agro-morphological traits and three molecular marker systems. The Mantel test showed a positive and significant correlation between tissue culture traits studied and each of agro-morphological traits and molecular marker systems.

Synthesis and Antimicrobial Activity of Some New 1-Alkyl-2-alkylthio-1,2,4-triazolobenzimidazole Derivatives

Mohamed, Bahaa Gamal,Hussein, Mostafa Ahmed,Abdel-Alim, Abdel-Alim Mohamed,Hashem, Mohammed The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.1

Some new derivatives of 1,2,4-triazolo[2,3-a]benzimidazoles were synthesized through the reaction of 1,2-diaminobenzimidazole with carbon disulfide. The resulting 1,2,4-triazolo-[2,3a]benzimidazole-2-thione intermediate was reacted with one equivalent of alkyl halides to give the corresponding 2-alkylthio derivatives, which were further alkylated through the reaction with another one equivalent of different alkyl halides to afford the target compounds; 1-alkyl-2alkylthio-1,2,4-traizolo[2,3-a]benzimidazoles. On the other hand, the 1,2-disubstituted derivatives with two identical alkyl substituents were prepared by the reaction of 1,2,4-triazolo[2,3-a]benzimidazole-2-thione with two equivalents of the alkyl halides. The structures of the new compounds were assigned by spectral and elemental methods of analyses. The synthesized compounds were tested for their antibacterial and antifungal activities. Most of the tested compounds proved comparable results with those of ampicillin and fluconazole reference drugs. The study indicated that, the antibacterial as well as the antifungal activities of the test compounds were improved with increase in the bulkiness of the introduced alkyl groups. Also, some active antibacterial compounds were tested for their antimycobacterial activity. All the test compounds showed equipotent antitubercular activity as that of INH as a reference drug.

Minimally Invasive Transforaminal Lumbar Interbody Fusion for the Surgical Management of Post-Discectomy Syndrome

Ahmed Bahaa Al Din AlShazli,Ashraf Yassin Amer,Ahmed Maher Sultan,Ahmed Samir Barakat,Wael Koptan,Yasser ElMiligui,Hesham Shaker 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.2

Study Design: This was a prospective case series of 30 patients with post-discectomy syndrome with an average of 18 months of follow-up (level IV). Purpose: The efficacy of post-discectomy syndrome managed by minimally invasive surgery transforaminal lumbar interbody fusion (MIS-TLIF) was evaluated. Overview of Literature: In post-discectomy syndrome wherein conservative treatment had failed, the best surgical treatment modality still remains controversial. Methods: Patients were functionally assessed using the Visual Analog Scale (VAS) for low back pain (LBP) and leg pain (LP) and Oswestry Disability Index (ODI). Radiological fusion was confirmed with plain X-rays and when indicated with computed tomography scan at 12 months postoperatively. A total of 30 patients with 37 operated at lumbar levels with failed discectomy surgery who met our inclusion criteria were treated with MIS-TLIF. Results: The ODI of all patients showed significant improvement from a mean of 73.78% preoperatively to 16.67% at 1 month and 14.13% at 12 months postoperatively. The preoperative LBP VAS score (mean, 4.37) showed a significant decrease (p<0.001) to 1.90 at 1 month and 1.10 at 12 months. Preoperative LP VAS score of limb pain averaged 7.53 and showed a significant (p<0.001) decrease to 3.47 at 1 month and 1.10 at 12 months. All patients attained radiological fusion at 12 months. Conclusions: MIS-TILF constitutes a valid and effective treatment option for patients with post-discectomy syndrome.

Influence of dual-task on postexercise facilitation : a transcranial magnetic stimulation study

Carmen Concerto,Bahaa Amer,Anaida Abagyan,Yisheng Cao,Carmenrita Infortuna,Eileen Chusid,Diego Coira,Fortunato Battaglia 한국운동재활학회 2016 JER Vol.12 No.3

Corrosion Behavior Optimization by Nanocoating Layer for Low Carbon Steel in Acid and Salt Media

( Ahmed S. Abbas ),( Bahaa Sami Mahdi ),( Haider H. Abbas ),( F. F. Sayyid ),( A. M. Mustafa ),( Iman Adnan Annon ),( Yasir Muhi Abdulsahib ),( A. M. Resen ),( M. M. Hanoon ),( Nareen Hafidh Obaeed ) 한국부식방식학회 2023 Corrosion Science and Technology Vol.22 No.1

In this paper, a SiC nano electroless nickel plating layer with excellent corrosion resistance was fabricated using the Taguchi method. The electroless plated low carbon steel was subjected to tests to examine the influence of corrosive media, microhardness, and corrosion rate on the corrosion resistance of this alloy. Three different corrosive media (HCl, Na₂SO₄, and NaCl) at various temperatures (80, 90, and 100 ℃) were used, and at three different times (40, 80, and 120 min.) with a speed of stirring equal to 500 rpm. The results of microhardness were found from 134.276 HV to 278.578 HV at various conditions, while the corrosion rate results were obtained from 0.89643 mpy to 7.12571 mpy at different circumstances. Corrosion, and mechanical characteristics were explained using Taguchi design. Taguchi technique was used to account for all possible combinations of elements in order to conduct a complete study. Models that link the response and procedure parameters were developed using the results of these tests, and the analysis of variance was utilized to validate these models (ANOVA). For maximum efficiency, a function called “desirability” was applied to all responses at once.