Exploratory Investigation for Some Universities' E-Learning Systems during Covid-19 Pandemic

Fatima Rayan Awad, Ahmed,Thowiba E., Ahmed,Rashid A., Saeed,Elmustafa Sayed, Ali,Ghada Elnour Elterafi, Abdelrhman,Somia Yousif Ahmed, Abutiraima International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.12

COVID pandemic has reshaped the world as it has been known to us and the education system is one of the most affected by it. Due to social distancing, quarantines and isolations have made it impossible for the knowledge transition to the masses using conventional methods. For cope with pandemic, the only other way available for some of the fortunate countries is the use of E-learning having somewhat the same traditional teaching method. This paper is concerned with the study of the preparedness of the learning system in some Sudanese universities due to the impact of the COVID-19 pandemic. Critical analysis has been performed to evaluate the current developing scenario, usage of the facilities available in open-source platforms, and the interaction of the universities folks with e-learning systems. The impact of such measures has been thoroughly investigated in this paper for Sudan which is already deprived of a proper education system. The investigation shows that the interact of the staff and the students with the system was acceptable where more than 85% of those enrolled to the system were interact properly and efficiently. The lecturers conducted through the platform were attended with more than 75% of the students. We also found that most of the lecturer were avoid to exam students by utilize the platform; where only 45% of the uploaded courses were conducted exams over Moodle platform. As Moodle is an open source and still need to be improved to be used for high examination credibility.

A novel 1,3,4‑thiadiazole modified chitosan: synthesis, characterization, antimicrobial activity, and release study from film dressings

Mohamed Ahmad E.,Elgammal Walid E.,Dawaba Aya M.,Ibrahim Ahmed G.,Fouda Amr,Hassan Saber M. 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.4

Herein, two new polymers designated as Cs-EATT and Cs-BATT have been synthesized via linking the chitosan with the synthesized 1,3,4-thiadiazole compounds. They were characterized using 1 H, 13 C-NMR, FT-IR, TGA, Elemental analysis, Mass spectrum, and UV–vis spectrophotometer. The synthesized polymers exhibit high activity to control the growth of pathogenic bacteria ( S. aureus , B. subtilis , E. coli, and P. aeruginosa ), and unicellular fungi ( C. albicans ). The MIC values were in the range of 25–100 µg mL –1 for Cs-EATT and 25–200 µg mL –1 for Cs-BATT with varied clear zones. The new polymers were mixed with three film-forming agents: polyvinyl alcohol, hydroxyethyl cellulose, and carboxymethyl cellulose to form six film dressings designated as E1, E2, and E3 for Cs-EATT, and B1, B2, and B3 for Cs-BATT, respectively. The evaluation of film dressings showed that the formed films had transparency, uniformity, homogeneity, elasticity, and non-irritation pH values for skin within the normal range. The maximum percentages of Cs-E/B-ATT content were recorded for film dressings E2 and B2, with values of 92.5% and 94.9%, respectively. Also, the release percentages varied according to film dressing formulation, with values in the ranges of 83.88–93.2% for Cs-EATT and (87.7–97.35%) for Cs-EATT after 9 h.

Effect of Ni substitution on structural, morphological and magnetic properties of Zn_1-xNi_xO nanorods

Ahmed, F.,Arshi, N.,Anwar, M.S.,Lee, S.H.,Byon, E.S.,Lyu, N.J.,Koo, B.H. Elsevier 2012 CURRENT APPLIED PHYSICS Vol.12 No.suppl2

We report the preparation of Zn<SUB>1-x</SUB>Ni<SUB>x</SUB>O nanorods through a chemical route using microwave irradiation. The obtained Zn<SUB>1-x</SUB>Ni<SUB>x</SUB>O nanorods were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Raman spectroscopy and magnetization measurements. XRD and TEM results showed that the Zn<SUB>1-x</SUB>Ni<SUB>x</SUB>O nanorods have single phase nature with wurtzite structure and Ni was successfully incorporated at Zn site into the ZnO. The shape of the nanorods changed from hexagon (length ~1.5 μm, diameter ~200 nm) to pencil like tip (length ~1 μm, diameter ~80 nm) by only changing the Ni content from 1% to 3% in ZnO. Concerning the Raman scattering spectra, the modification in the intensity of E<SUB>2</SUB><SUP>high</SUP> mode and sub-band edge emissions provides enough evidence for the existence of intrinsic defects associated with the O atoms. Magnetic measurement results revealed that Zn<SUB>1-x</SUB>Ni<SUB>x</SUB>O nanorods show the well-defined ferromagnetic features at room temperature and the value of M<SUB>s</SUB> increased with the increase of Ni concentration.

Effects of Resveratrol and Essential Oils on Growth Performance, Immunity, Digestibility and Fecal Microbial Shedding in Challenged Piglets

Ahmed, S.T.,Hossain, M.E.,Kim, G.M.,Hwang, J.A.,Ji, H.,Yang, C.J. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.5

A study was conducted to evaluate the effects of resveratrol and essential oils from medicinal plants on the growth performance, immunity, digestibility, and fecal microbial shedding of weaned piglets. A total of 48 weaned piglets (8 kg initial weight, 28-d-old) were randomly allotted to four dietary treatments with 3 replications of 4 piglets each. The dietary treatments were NC (negative control; basal diet), PC (positive control; basal diet+0.002% apramycin), T1 (basal diet+0.2% resveratrol), and T2 (basal diet+0.0125% essential oil blend). All piglets were orally challenged with 5 ml culture fluid containing $2.3{\times}10^8$ cfu/ml of Escherichia coli KCTC 2571 and $5.9{\times}10^8$ cfu/ml Salmonella enterica serover Typhimurium. The PC group (p<0.05) showed the highest average daily gain (ADG) and average daily feed intake (ADFI) throughout the experimental period, although feed conversion ratio (FCR) was improved in the T1 group (p>0.05). Serum IgG level was increased in the T1 group, whereas TNF-${\alpha}$ levels was reduced in the supplemented groups compared to control (p<0.05). The PC diet improved the dry matter (DM) digestibility, whereas PC and T2 diets improved nitrogen (N) digestibility compared to NC and T1 diets (p<0.05). Fecal Salmonella and E. coli counts were reduced in all treatment groups compared to control (p<0.05). Fecal Lactobacillus spp. count was increased in the T2 group compared to others (p<0.05). Dietary treatments had no significant effect on fecal Bacillus spp. count throughout the entire experimental period. Based on these results, resveratrol showed strong potential as antibiotic alternatives for reversing the adverse effects of weaning stress on growth performance, immunity and microbial environment in E. coli and Salmonella-challenged piglets.

Phytotherapeutic effects of Echinacea purpurea in gamma-irradiated mice

Yasser E. Shahein,Amira M. K. Abouelella,Sameh S. Tawfik,Ahmed M. Zahran1 대한수의학회 2007 Journal of Veterinary Science Vol.8 No.4

Echinacea (E.) purpurea herb is commonly known as the purple coneflower, red sunflower and rudbeckia. In this paper, we report the curative efficacy of an Echinacea extract in γ-irradiated mice. E. purpurea was given to male mice that were divided into five groups (control, treated, irradiated, treated before irradiation & treated after irradiation) at a dose of 30 mg/kg body weight for 2 weeks before and after irradiation with 3 Gy of γ-rays. The results reflected the detrimental reduction effects of γ-rays on peripheral blood hemoglobin and the levels of red blood cells, differential white blood cells, and bone marrow cells. The thiobarbituric acid-reactive substances (TBARs) level, Superoxide dismutase (SOD) and glutathione peroxidase (GSPx) activities and DNA fragmentation were also investigated. FT-Raman spectroscopy was used to explore the structural changes in liver tissues. Significant changes were observed in the microenvironment of the major constituents, including tyrosine and protein secondary structures. E. purpurea administration significantly ameliorated all estimated parameters. The radio-protection effectiveness was similar to the radio-recovery curativeness in comparison to the control group in most of the tested parameters. The radio-protection efficiency was greater than the radio-recovery in hemoglobin level during the first two weeks, in lymphoid cell count and TBARs level at the fourth week and in SOD activity during the first two weeks, as compared to the levels of these parameters in the control group

Screening of Lactobacilli Derived from Fermented Foods and Partial Characterization of Lactobacillus casei OSY-LB6A for Its Antibacterial Activity against Foodborne Pathogens

Hyun-Jung Chung,Ahmed E. Yousef 한국식품영양과학회 2009 Preventive Nutrition and Food Science Vol.14 No.2

Various fermented foods were screened in search of food-grade bacteria that produce bacteriocins active against Gram-negative pathogens. An isolate from a mold-ripened cheese presented antibacterial activity against Gram-positive and Gram-negative bacteria. The most active isolate was identified as Lactobacillus casei by a biochemical method, ribotyping, and membrane lipid analysis, and was designated as OSY-LB6A. The cell extracts of the isolate showed inhibition against Escherichia coli p220, E. coli O157, Salmonella enerica serovar Enteritidis, Salmonella Typhimurium, and Listeria monocytogenes. The antibacterial nature of the cell extract from the isolate was confirmed by eliminating the inhibitory effects of acid, hydrogen peroxide, and lytic bacteriophages. The culture supernatant and cell extract retained antibacterial activity after heating at 60~100℃ for 10~20 min. The activity of the cell extract from Lb. casei was eliminated by pronase and lipase. Finally, the cell extract showed a bactericidal mode of action against E. coli in phosphate buffer solution, but it was bacteriostatic in broth medium and food extracts.

Screening of Lactobacilli Derived from Fermented Foods and Partial Characterization of Lactobacillus casei OSY-LB6A for Its Antibacterial Activity against Foodborne Pathogens

Chung, Hyun-Jung,Yousef, Ahmed E. The Korean Society of Food Science and Nutrition 2009 Preventive Nutrition and Food Science Vol.14 No.2

Various fermented foods were screened in search of food-grade bacteria that produce bacteriocins active against Gram-negative pathogens. An isolate from a mold-ripened cheese presented antibacterial activity against Gram-positive and Gram-negative bacteria. The most active isolate was identified as Lactobacillus casei by a biochemical method, ribotyping, and membrane lipid analysis, and was designated as OSY-LB6A. The cell extracts of the isolate showed inhibition against Escherichia coli p220, E. coli O157, Salmonella enerica serovar Enteritidis, Salmonella Typhimurium, and Listeria monocytogenes. The antibacterial nature of the cell extract from the isolate was confirmed by eliminating the inhibitory effects of acid, hydrogen peroxide, and lytic bacteriophages. The culture supernatant and cell extract retained antibacterial activity after heating at $60{\sim}100^{\circ}C$ for $10{\sim}20$ min. The activity of the cell extract from Lb. casei was eliminated by pronase and lipase. Finally, the cell extract showed a bactericidal mode of action against E. coli in phosphate buffer solution, but it was bacteriostatic in broth medium and food extracts.

Hibiscus sabdariffa L.: phytoconstituents, nutritive, and pharmacological applications

Mohamed A. Salem,Ahmed Zayed,Magy E. Beshay,Mesih Mirna M. Abdel,Khayal Reem F. Ben,Fady A. George,Shahira M. Ezzat 경희대학교 융합한의과학연구소 2022 Oriental Pharmacy and Experimental Medicine Vol.22 No.3

Hibiscus sabdariffa L. (HS) calyx extracts have been well-documented for the treatment of hypertension, liver dysfunctions, and diabetes among others. An updated concise review of HS regarding phytoconstituents, and involved putative mechanisms of potential biological activities is presented. HS showed other food and other industrial applications, including the preparation of metallic nanoparticles. These activities were explained by the presence of a broad spectrum of valuable phytochemicals, including the red pigments anthocyanins, phenolic, and organic acids and polyphenolics (e.g., flavonoids and tannins). Most of the bioactivities were found to be associated with anthocyanins-rich extracts. Anthocyanins were found to have various mechanisms for the treatment of hypertension, including direct vasodilation and inhibition of angiotensinconverting enzyme (ACE). However, leaves and seeds showed also other potential applications in food industry, owing to the significant amounts of phenolic antioxidant compounds. Therefore, valorization and optimization of bioactive constituents’ extraction from plant biowastes should be considered for maximizing the benefits of HS extracts.

Inactivation of Barotolerant Strains of Listeria monocytogenes and Escherichia coli O157:H7 by Ultra High Pressure and tert-Butylhydroquinone Combination

Yoon-Kyung Chung,Ahmed E. Yousef 한국미생물학회 2008 The journal of microbiology Vol.46 No.3

Antimicrobial efficacy of ultra-high-pressure (UHP) can be enhanced by application of additional hurdles. The objective of this study was to systematically assess the enhancement in pressure lethality by TBHQ treatment, against barotolerant strains of Escherichia coli O157:H7 and Listeria monocytogenes. Two L. monocytogenes Scott A and the barotolerant OSY-328 strain, and two E. coli O157:H7 strains, EDL-933 and its barotolerant mutant, OSY-ASM, were tested. Cell suspensions containing TBHQ (50 ppm, dissolved in dimethyl sulfoxide) were pressurized at 200 to 500 MPa (23±2°C) for 1 min, plated on tryptose agar and enumerated the survivors. The TBHQ-UHP combination resulted in synergistic inactivation of both pathogens, with different degrees of lethality among strains. The pressure lethality threshold, for the combination treatment, was lower for E. coli O157:H7 (≥ 200 MPa) than for L. monocytogenes (> 300 MPa). E. coli O157:H7 strains were extremely sensitive to the TBHQ-UHP treatment, compared to Listeria strains. Interestingly, a control treatment involving DMSO-UHP combination consistently resulted in higher inactivation than that achieved by UHP alone, against all strains tested. However, sensitization of the pathogens to UHP by the additives (TBHQ in DMSO) was prominently greater for UHP than DMSO. Differences in sensitivities to the treatment between these two pathogens may be attributed to discrepancies in cellular structure or physiological functions.

Towards Enabling Unmanned Aerial Vehicles as a Service for Heterogeneous Applications

Farid Nait-Abdesselam,Ahmad Alsharoa,Mohamed Y. Selim,Daji Qiao,Ahmed E. Kamal 한국통신학회 2021 Journal of communications and networks Vol.23 No.3

The increasing use of unmanned aerial vehicles (UAVs) invarious commercial applications, such as precision agriculture andaerial remote sensing, is fast contributing to a significant growthin the UAV market. Also, it is crucial to provide continuous cov erage after failures of wireless network components or additionalbandwidth in high traffic situations. By introducing the concept ofUAVs as a service (UaaS), we propose a novel framework, dubbed 3S, consisting of four phases: Demand, decision, deployment,and service. The main objective of this framework is to provide arealistic and streamlined approach to support the implementationof the UaaS paradigm. The technical problems involved include de termining the type and number of UAVs to be deployed and theirfinal locations (e.g., hovering or on-ground). They also include thetrajectory planning, possibly several times, between charging sta tions and deployment locations. We present the application of the 3S framework to two case studies with the goal of providing wire less connectivity services to (i) static users after failures of wirelessnetwork components, including long-term and short-term failures,and (ii) dynamic users in wireless relaying systems.