The present study was done to identify the karyotype of Mystus pelusius fish , which is the only representative of the family Bagridae in Iraq, they have been caught from Tigris river in AL-Kraat area of Baghdad city, the results show that the diploid chromosome number was 2n=32 and the males chromosomal types included 2n=(6m+13sm+7st+6t)and fundamental number FN=51, in females chromosomal types included 2n=(6m+12sm+8st+6t)with FN=50,also it observed that the first submetacentric pair was the largest within the biarmed chromosomes .The results revealed that the male heterogamety and the female homogamety , accordingly it follows the sex determination system (XX / XY) , as the (X) chromosome represented by medium sized submetacentric (sm)chromosome and (Y)chromosome by small sized subtelocentric (st) chromosome.
The Study of Chromosomal Structure in Mystus pelusius (Solander in Russell,1794) Fish
Karyotype
Mystus pelusius
Bagridae and Sex determination system.
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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