امیر چراغی

Today, one of the effective factors for sustainable economic growth and development is efficient investment that can create value for shareholders. The purpose of this research is to investigate the relationship between social responsibility and investment efficiency.

To test the research hypotheses, a multiple linear regression model based on panel data has been used.

The results of a survey of 140 companies listed on the Tehran Stock Exchange during the period 2013 to 2021 indicate that there is a negative and significant relationship between disclosure of corporate social responsibility information and investment efficiency, and in the years when disclosure of corporate social responsibility information is more The level of investment efficiency has been lower.

The results showed that there is a positive and significant relationship between aggressive strategy and over-investment and in the years that the company has chosen an offensive strategy, there has been more investment in the company. There is also a positive and significant relationship between defensive strategy and low investment, and in the years that the company has chosen a defensive strategy, there has been less investment in the company. The results also showed that corporate social responsibility has a negative and significant effect on the relationship between aggressive strategy and over-investment and in years when the disclosure of corporate social responsibility information has been more, the impact of aggressive strategy on over-investment is weak. In addition, corporate social responsibility has a positive and significant effect on the relationship between defensive strategy and over-investment, and in years when the disclosure of corporate social responsibility information has been more, the effect of defensive strategy on over-investment is strengthened.

Mastitis is one of the most costly diseases in the veterinary industry, which in addition to financial losses, has many health consequences for human society. Staphylococcus aureus is one of the most important causes of this disease in livestock, which has a very high resistance to a wide range of industrial drugs due to the indiscriminate use of antibiotics and the presence of some microbiological properties. In this study, the Sahendica sage plant with the scientific name (Satureja Sahendica) was used for this purpose. For this study, after sampling the milk of mastitis animals, the samples were taken under sterile conditions and transferred to the laboratory beside the ice, and after culturing the sample in laboratory culture media and confirming the presence of Staphylococcus aureus. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MBC) values ​​were determined for this species. The results showed that the essential oil of this plant in the average concentrations of 2.3±0.82 mg/ml for (MIC) and 10.14±3.66 mg / ml for (MBC) is effective on the bacterium. Finally, it was found that Sahandika safflower essential oil can be used to prevent the growth of Staphylococcus aureus to control the development of antibiotic resistance.

Acariphagous ladybird beetle, Stethorus gilvifrons Mulsant (Col., Coccinellidae) feeds on various growth stages of the tetranychus mites. Since Eutetranychus orientalis (Klein) mite is actively seen on castor bean crops during the months of autumn, winter and spring seasons, so it can be considered as a suitable host for maintaining ladybird beetles. Hence, the ladybird beetle population can be prevented from migration and maintained until the outbreak of sugarcane mite. In this study, possible use of castor bean, Ricinus communis Wild. (Euphorbiaceae) has been considered as a banker plant of acaraphagous ladybird beetle, S. gilvifrons. Initially, 30 castor bean plants were cultivated in the month of August 2016 around sugarcane fields in Khuzestan province and the population of mites and ladybird beetles were monthly sampled during one year (2016-2017) starting from August. The results showed ladybird beetles activity on castor bean plant throughout the year, however, during November till March only adults were observed that could start reproduction only from April to September. Also, the data analysis of the olfactometry system showed that the reaction of the ladybird beetle to volatile compounds of castor bean is significant. Therefore, the castor bean has the potential to form a niche for the acaraphagous ladybird beetle in maintaining its population throughout the year in order to control sugarcane mite population more efficiently and timely.