الهام کوهی

Considering the important role of intercropping in achieving high yield and increasing the stability of agricultural systems, this research was conducted in order to determine the most suitable pattern of mixed cultivation of broad beans and green beans and to investigate its effect on the growth and performance of urban green beans. 

The field experiment was carried out as a randomized complete block design (RCBD) with six treatments and four replications at the research farm of the University of Tabriz, Faculty of Agriculture during 2015 growing season. Treatments were included sole planting of broad beans and Balangu and four patterns of intercropping systems including (100:20, 100:40, 100:60, and 100:80 rate of faba bean and Balangu. 

The results showed that the sole cultivation of Balanghu had the highest biological performance and seed yield, which was significantly different from other treatments related to mixed cropping patterns. In all intercropping treatments, the ratio of land equality and total relative value was greater than one, which indicates the superiority of mixed cropping over pure cropping. 

According to the obtained results, the mixed cultivation of 80% Balanghu + 100% faba beans with the highest LER (1.48) and RVT (1.45) is the best cultivation pattern due to the optimal use of available resources.

Pyramidal and network ownership structures, which give ultimate owners greater control rights over companies than cash flow rights, are prevalent in the Iranian stock market. Given the complex shareholding networks and significant changes in the ownership structures of large Iranian firms over the past two decades, this study aims to examine the relationship between ownership structure and company performance. Four measures are used to analyze ownership structure: cash flow right of the largest shareholder, wedge between control right and cash flow right of the largest shareholder, difference in cash flow rights of the two largest shareholders, and type of ownership. The study investigates their relationship with the performance and stock returns of 261 listed companies during the period of 2015 to 2020. The results indicate a positive and significant association between the cash flow right of the largest shareholder and firm performance, but only when the largest shareholder owns at least 15% of the company's shares. For firms with only one owner and less than 50% in control rights, there is no significant correlation between the cash flow right of the largest shareholder and performance. The study also reveals that ownership by insurance companies has a positive correlation with firm performance, while quasi-governmental ownerships have a negative correlation with performance.

Knowledge about drought, is the most important prerequisite to reduce risk of drought damage. This study was done in Fars Province, using monthly data of 10 synoptic stations at period of 1990 to 2014. RDI index and Markov chain model used for drought monitoring and forecasting, respectively. Drought severity and expected status were analyzed. Results indicated that, the possibility of transmission to normal class was higher than possibility of transmission to other classes. The probability of drought balances, in monitoring stage, obtained 3.37, 8.88, 8.33, 63.2, 15.68, 0.6 and 0.00% for extremely drought, very drought, moderately drought, normal, moderately wet, very wet and extremely wet periods, respectively. The probability of drought balances, in forecasting stage, obtained 3.95, 10.46, 10.68, 55.51, 18.37, 1.00 and 0.00% for extremely drought, very drought, moderately drought, normal, moderately wet, very wet and extremely wet periods, respectively. Generally in Fars province, in forecasting stage, the frequency of occurrence of drought classes were higher than frequency of occurrence of wet classes that indicate the continuous persistence of drought in this province. Maximum and minimum frequency of drought occurrence classes obtained 31.5% and 20% at Izadkhast and Shiraz synoptic stations, respectively.

Today, computer games have become an integral part of the lives of children, adolescents, young adults and adults. This study aimed to explore the impact of computer games on mental health of secondary school students (third grade) in schools of 19 stricts of Tehran, Iran.

The method of study was retrospective, and pretest-posttest type. The study sample consisted of students in third-grade primary schools in Tehran. The sample size was selected using Cochran formula (897). The research tools were mental health and research-made questionnaires. The validity of the latter was verified by A.P experts and relevant specialists. The reliability of the research was validated based on Cronbach’s coefficient as 0.79. Data analysis was conducted using descriptive statistics (tables of tendency to center and distribution indexes and frequency tables) and inferential statistics (one-way ANOVA) as well as SPSS software.

The significance level obtained for the relationship between the use of computer games and different aspects of health were as follows: aggression 0.001, depression 0.002, anxiety 0.003, interpersonal sensitivity 0.003, less than (0.005). The results reject the null hypothesis for all the research hypotheses, and hypotheses regarding the relationship between the use of computer games and various aspects of health were confirmed.

The research findings statistically suggest that students who do not play computer games are in much better conditions in terms of mental health level in all dimensions (aggression, depression, interpersonal sensitivity and physical symptoms) compared with students who play more or less. Furthermore, planning to optimize the use of leisure time in students can prevent the spread of inappropriate games.

The present study aimed to investigate the role of mass media in the development of sustainable tourism in the Amol City. Data collection has been done by questionnaire which its validity was confirmed by relevant experts and specialist and reliability of the questionnaire was validated by Cronbach's test with 0.74coefficient. Data analysis was done using descriptive statistic (frequency, net percentage, etc.), inferential statistic (one sample t test) and SPSS software. The findings indicate that there is a relation between the level of access to the mass media, cultural influence, media advertising, and access to amenities (Audiovisual). Results showed that in the study area considering distributed field works between tourists, mass media had an effective role in the introduction and development of sustainable tourism of that area.