فهرست مطالب razieh ghorbani

The main objective of the present research is to identify the relationship between credit rating, litigation risks, and audit opinion modification on the companies listed on the Tehran Stock Exchange (TSE).

The statistical sample of this study includes 158 companies accepted on the Tehran Stock Exchange, which were reviewed from 2017 to 2021. This research is an applied and post-event type. The research hypotheses were tested through logistic regression in version 10 of Eviews software.

The research findings showed that when credit rating increased, litigation risks decreased. Also, a negative and significant relationship exists between credit rating and audit opinion modification.

Originality/Value:

 This study clarifies the role of credit rating in audit reports and litigation risk management and provides new insight into the factors that affect audit opinion modification. These findings have important implications for companies, auditors, and investors in increasing the quality and reliability of financial information. This study also contributes to the development of literature by emphasizing the need for more research on the factors that determine credit rating and their impact on financial reporting.

In order to identify loci controlling seedling morpho-physiologic characteristics in 88 bread wheat cultivars, a greenhouse experiment based on simple alpha lattice was conducted under both normal and 120 mM (12 ds/m) salt stress condition of the Faculty of Agriculture, Urmia University in 2020-2021 cropping season. Chlorophyll a, b and carotenoid content, proline, plant fresh and dry weight, plant height and leaf relative water content (RWC), Na+, K+ and K+/Na+ concentrations were measured. After genotyping by sequencing with Ion Torrent technology and removal of SNPs with more than 20% of missing data and minor allele frequency less than 5%, a total of 5869 SNP markers were identified. Based on association mapping with the mixed linear model (MLM) method, a total of 25 marker-trait associations were detected under normal conditions. The A and D genomes had the highest and lowest number of significant marker-trait associations (MTAs). Among the studied traits under normal conditions, chlorophyll a had the highest number of MTAs on 1A, 3B, 3D, 5B, 7A chromosomes with eight MTAs. A total of 21 MTAs were identified under salt stress conditions which the genome B and D had the highest and lowest number of MTAs, respectively. Five MTAs were identified for plant fresh weight, which were located on chromosomes 4A and 6B. The results of this study provide valuable information about the loci associated with the studied traits, which can be used in marker assisted selection in wheat breeding programs after confirmation in biparental populations and additional experiments.

As a sensitive issue, companies’ social responsibility has grabbed much attention in recent years. Since social capital is a means to achieve individual, collective, and social goals and benefits, the purpose of this study was examining the effect of business strategy on the relationship between companies’ social responsibility and value in order to increase social capital. To this end, a sample of 160 companied enlisted on Tehran Stock Exchange in the 2010-2019 period was used to test the study hypotheses. The findings of the study revealed the business strategy variable as the moderating variable affecting the relationship between a company’s social capital and value. Future studies are suggested to examine the relationship between a company’s social responsibility and value through other variables.

Telomeres are the sequence of DNA at the end of the eukaryotic chromosome that is essential for genome integrity. Several studies have shown that telomere length in sperm differs between individual men and individual spermatozoa. In addition, decreased telomere length in sperm from infertile men are associated with the reduction of fertility potential and embryo quality. In this regard, previous studies showed that density gradient centrifugation (DGC) and swim up are useful techniques for separation of sperm with longer telomeres. On the other hand, recent studies showed that selection of sperm based on surface negative electric charge or “Zeta potential”, can separate high percentage of sperm with intact chromatin compared to DGC alone, and also the combination of DGC-Zeta can improve clinical outcomes in infertile men candidate for intracytoplasmic sperm injection (ICSI). Therefore, we compared sperm telomere length and DNA fragmentation between two sperm preparation procedures (DGC and Zeta).

In this experimental study, we assessed sperm telomere length and DNA fragmentation by quantitative Real-time PCR and TUNEL assay, respectively in prepared spermatozoa by either DGC or Zeta method of fifteen infertile men with normozoospermia from September 2017 to December 2017. Sperm telomere length was expressed as relative, and absolute.

When the results compared to washed semen samples or control, we did not observe any significant difference in mean of relative or absolute sperm telomere length after DGC or Zeta method (P>0.05). While the mean percentage of DNA fragmentation was significantly lower in both DGC or Zeta methods compared to control (P<0.05).

This is the first study that compared the effect of DGC and Zeta sperm preparation methods on sperm telomere length and concluded that both these methods can select sperm population with high DNA integrity and same sperm telomeres length.

Approximately 40-50% of infertility is due to male factor infertility that abnormal sperm chromatin structure as a major cause of infertility has been suggested. Protamines are the major components of sperm chromatin and play a central role in the correct chromatin packaging. Several studies have shown that the protamine deficiency in sperm is associated with low sperm quality and infertility. Considering the importance of protamine infertility, the purpose of this review article was to study the protamine content and it’s biological significance in male fertility.

Published papers by researchers in the Google Scholar, Science Direct and PubMed databases were collected from 1874 to 2018, and the best and most efficient papers were considered for this study.

Several studies have shown that there is a significant reverse relationship between protamine deficiency in sperm with fertilization and pregnancy rate following assisted reproduction techniques and central cause of protamine deficiency in sperm is due to the increase of oxidative stress which consequently causes to DNA damage.

Treatment with antioxidants can reduce oxidative stress in infertile men, and improve sperm parameters, sperm protamine content, and DNA integrity.