Underexpression of hsa-miR-449 family and their promoter hypermethylation in infertile men: A case-control study

Background: Post-transcriptional microRNAs (miRNAs) have an important pattern in the spermatogenesis process. Objective: Study of the expression and methylation of hsa-miR-449 family in sperm samples of infertile men. Materials and Methods: In this case-control study, we recruited 74 infertile men (with asthenozoospermia, teratozoospermia, asthenoteratozoospermia, and oligoasthenoteratozoospermia) and 30 control samples. Methylation-specific PCR (MSP) method was used for methylation evaluation of hsa-miR-449 a, b, c promoter. By Real time PCR (qRT-PCR) method,we showed downregulation of hsa-miR-449 a, b, c in the sperm samples of infertile men and compared it to their fertile counterparts. Results: There was significant underexperssion, in hsa-miR-449-b in oligoasthenoteratospermic samples (p = 0.0001, F = 2.9). About the methylation pattern, infertile men showed high frequency of methylation in the promoter of hsa-miR-449 a, b, c in comparison to controls (60.8% vs 23.3%), the highest amount of methylation was observed in oligoasthenoteratospermia samples (81.2%). Conclusion: In this study, low expression and high methylation of hsa-miR-449-b were observed in infertile men in compared to control samples, which can be one of the causes of defective spermatogenesis. Key words: Spermatogenesis, miR-449, Expression, Epigenetic

The Survey of NOX Distribution Using Dispersion Models AERMOD and CALPUFF at a Gas Refinery

Background & Objectives: Nowadays, air pollution is one of the major challenges in the world, therefore, in the present study, according to the importance of the fourth refinery gas as the largest gas refinery in the region, the amount of emissions from stacks has been initially determined and then the distribution has been identified in the region. Methods: In this research, AERMOD and CALPUFF models have been used as the tools for the analysis of NOX emissions of stacks of 4th South Pars gas refinery located in Assaluyeh. First, NOX emissions from refinery stacks have been obtained by field measurements. Then, the distribution of these emissions has been examined using dispersion models AERMOD and CALPUFF in an area of 50 × 50 km in each direction x and y in the one-year period of 2013 to the average time of 1, 3, 8, and 24 and the amounts resulting from the implementation of the models have been compared to the results of field measurements at 9 receiving stations as a separate receptors in the model. Results: Review of charts and statistical parameters has shown that, according to the evaluation of predictions made, the CALPUFF model was better than AERMOD model, in the studied area. Conclusion: It could be concluded that performance of both models to predict the concentration of pollutants in the region can be generally considered acceptable

Investigating the Efficiency of Combined Cycle Power Plants with the Data Envelopment Analysis Process (with an Emphasis on Air Pollution)

Performance management is one of the most significant strategies in promoting the efficiency of organizations and is highly sensitive. It is important to check the efficiency of combined cycle power plants because of their major contribution to power generation and air pollution. This study was conducted to evaluate the economic and environmental efficiency of Combined Cycle Power Plants (CCPPs). The inputs and outputs required to evaluate the performance of the power plants were determined according to expert opinions. Then, the 7-year statistics and information of the Qom, Neishabour, Shahid Rajaee, Yazd and Kerman power plants were collected as the desired CCPPs in Iran. The Window Data Envelopment Analysis (WDEA) method was used for evaluating the efficiency of the power plants. The 3-year window length showed that most of the power plants were efficient. Only the Rajaee, Neishabour and Yazd power plants were ineffective in some years. The mean efficiency of the power plants in the 4-year window length showed that the plants were efficient from 2008 to 2010

Dispersion Modeling of CO with AERMOD in South Pars fourth Gas Refinery

Background: Air quality modeling can be considered as a useful tool to predict air quality in future and determine the control strategies of emissions abatement. In this study, AERMOD dispersion model has been applied as a tool for the analysis of the values of CO emissions from the stacks and flares of South Pars fourth Gas Refinery located in Asaluyeh. Methods: First, the values of CO  emissions from the refinery's stacks and flares were investigated by measurement and using the emission factors in four seasons of 2013. Then, dispersion of pollutants was predicted by using the AERMOD model in the region with area of 10×10 km2  in each direction of x and y, in average times of 1, 3, 8, 24-hours and for the annual statistical period. Then the predicted and field measurement values in 9 receptors have been compared. Results: Statistical evaluation showed that the correlation coefficient values for CO were 0.85 in spring, 0.89 in summer, 0.96 in fall, and 0.95 in winter. The maximum concentration of CO was occurred in local scale of 10×10 km2. Conclusion: Comparison of maximum 1-hour and 8-hour concentrations of the predicted results with the national and international standards showed that CO concentration is higher than standard values. In total, according to the evaluation of the predictions made, the performance of AERMOD model was acceptable in prediction of CO concentrations in the study area