Search

Weighted distribution is a valuable method for constructing flexible models and analyzing data sets. In this paper, a new weighted distribution of skew-normal is introduced with four parameters. The proposed model is a generalized version of several distributions, such as normal, bimodal normal, skew-normal, and skewed bimodal normal-normal. This weighted model is form-invariant under the proposed weight function. The basic characteristics of the model are expressed. A method has been used to generate data from the model. The maximum likelihood estimations of parameters are given and evaluated using a simulation study. The model is fitted to the three real data sets. The advantage of the proposed model has been shown on the rival distributions using appropriate criteria. [ABSTRACT FROM AUTHOR]

Copyright of Colombian Journal of Statistics / Revista Colombiana de Estadística is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Multiple sclerosis (MS) is a chronic, demyelinating, autoimmune and also complex disease of the central nervous system the etiology of which is not completely defined; but both genetic and environmental factors are regarded as main factors in its susceptibility. HLA-DQB1*0602 is considered as one of the most important genetic factors in MS predisposition but contradictory results have been reported in different populations worldwide. Since there are no data with respect to the correlation of HLA-DQB1*0602 and multiple sclerosis in Khuzestan province, and because of ethnic diversity in Khuzestan province, the aim was to examine the association of this aliele with multiple sclerosis in Khuzestan. Methods: This is a case-control study that evaluated 200 MS patients from Khuzestan and 200 healthy individuals from the same geographical region. DNA extraction was performed by salting out method; in addition, HLA typing was carried out by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) method. The present study also considered probable association among HLA-DQB1*0602 with sex, ethnicity, and type of disease. Results: Results revealed that distribution of mentioned allele was not statistically different among cases and controls (61.5% vs. 64%, P = 0.605); furthermore, no association was shown between this allele and gender, ethnicity or type of disease. Conclusion: On the whole, our result is consistent with most of the other studies in Iran; but contrasts with most of the studies in European populations. [ABSTRACT FROM AUTHOR]