This study was conducted to evaluate the effects of black tea on Pseudomonas
aeruginosa isolated from eye infection. One hundred samples (corneal scrapings)
were obtained. Approximately, 77% of the cases were due to contact lens wear
followed by 15 % trauma and 8% with unknown history. The isolates identified as
P. aeruginosa were 30% (23/77 CL) and 25% (2/8 Unknown). On the other hand,
the Kirby-Bauer antibiotic sensitivity assay showed that 100% of the isolates were
sensitive to Neomycin, Gentamicin and Amikacin. While 91.6% were sensitive to
Carbenicillin and Ceftriaxone; 66.6% were sensitive to Cefotaxime and 0% were
sensitive to Tertacycline. Only two isolates were found to be multidrug resistant.
Screening for some Pseudomonas virulence factors such as hemolysin and protease
showed that all the isolates had the ability to produce Beta hemolysin and digested
casein due to protease secretion. For adhesion ability using Christensen’s method,
8.33% were recorded as strong (+++), 41.66% were moderate (++) while 50% were
weak (+).In contrast black tea (Camellia sinensis) was examined for its
antimicrobial activity. The agar-well diffusion method was used for the
concentrations 100, 200, 300, and 400mg/ml respectively. Results showed that the
minimum inhibitory concentration of tea alcohol extract was 400mg/ml with
inhibition zone of 20mm. The extract decreased the bacterial viable count since it
showed a visible decrease to <5×10P
6
P Colony Forming Unite (CFU)/ml after 24 hours
of incubation. Black tea extract also had the ability to completely inhibit
Pseudomonas growth on blood agar and inhibited protease activity and adhesion.
There were also differences in Congo red binding seen in bacterial cell suspensions
cultured in growth media that contained tea extract. The synergistic activity of tea
extract with antibiotics has changed the resistance of P. aeruginosa (without the tea)
to sensitive (in presence of tea extract).
Antimicrobial Effects of Black Tea (Camellia sinensis) on Pseudomonas Aeruginosa Isolated from Eye Infection
Keratitis
.
Pseudomonas aeruginosa
Contact lenses
Antibiotic Sensitivity test
Virulence factors
Adhesion
Camellia sinensis
Agar-well diffusion method
Synergistic Activity
Publication Date
Wed Apr 25 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Different Estimation Methods for System Reliability Multi-Components model: Exponentiated Weibull Distribution
Exponentiated Weibull Distribution (EWD)
Reliability of multi-component Stress – Strength models R(s
k)
Maximum likelihood estimator (MLE)
Moment estimator (MOM)
shrinkage method (Sh)
Least Squares Estimator (LS)
Rank Set Sampling (RSS). and mean squared error (MSE).
In this paper, estimation of system reliability of the multi-components in stress-strength model R(s,k) is considered, when the stress and strength are independent random variables and follows the Exponentiated Weibull Distribution (EWD) with known first shape parameter θ and, the second shape parameter α is unknown using different estimation methods. Comparisons among the proposed estimators through Monte Carlo simulation technique were made depend on mean squared error (MSE) criteria
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Publication Date
Thu Aug 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
مقارنة مقدرات بيز لدالة المعولية لتوزيع باريتو من النوع الاول باستعمال دوال معلوماتية مضاعفة مختلفة
Pareto type I distribution
reliability function
bayes method
double prior distributions (chi-gamma square distribution. gamma- erlang distribution
erlang exponential distribution
the squared error loss function.
توزيع باريتو من النوع الاول
دالة المعولية
طريقة بيز
الدوال المعلوماتية المضاعفة : توزيع مربع كاي- كاما
توزيع كاما - ارلنك
التوزيع ارلنك- الاسي
دالة الخسارة التربيعية.
The comparison of double informative priors which are assumed for the reliability function of Pareto type I distribution. To estimate the reliability function of Pareto type I distribution by using Bayes estimation, will be used two different kind of information in the Bayes estimation; two different priors have been selected for the parameter of Pareto type I distribution . Assuming distribution of three double prior’s chi- gamma squared distribution, gamma - erlang distribution, and erlang- exponential distribution as double priors. The results of the derivaties of these estimators under the squared error loss function with two different double priors. Using the simulation technique, to compare the performance for
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Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Theoretical And Applied Information Technology
Factors affecting global virtual teams’ performance in software projects
Today the trend is to perform software development work via distributed geographical area among team
individual or even as an organization. However
due to the global market and international presence of many companies
there is a need to implement a global virtual teams. The global virtual team members are gradually engaged in globalized business environments across space
time and organizational boundaries via information and communication technologies. A global virtual team relies on communication
collaboration
and information exchange are the most important criteria in global virtual teams’ operations. The purpose of this paper is to answer two research questions. The first research question is to identify the factors affecting global virtual teams’ performance. A systematic literature review was conducted to answer the first research question. The second research question is on what the rank of the factor affecting the global virtual teams’ performance according to their level of effect on global virtual teams’ performance. Online survey was conducted within 103 developers and IT managers from eight IT companies to answer the second research question. The Statistical Package for Social Science (SPSS 22) was used to analyze the collected data. In this study
we investigated factors that affect global virtual teams’ performance
factors considered include cultural differences
language problems
time-zone differences
team size
technical problems
lack of trust
lack of sufficient training
and ICT problems. Also the findings indicated that lack of sufficient training is the highest level of effect on global virtual teams’ performance. On the other hand
team size is the lowest level of effect on global virtual teams’ performance. © 2005 - 2016 JATIT & LLS. All rights reserved.
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