درخت حوزه‌های تخصصی

This study aims at investigating the effects of the change in the information environment from risk to ambiguity, disclosure dynamics, and the ambiguity aversion behavior of investors on the disclosure of integrated information for selected corporates operating in digital industry listed on the Tehran Stock Exchange during 2012-2022. The corporate voluntary disclosure lag, stock return volatility, and the probability of favorable returns incidence represent respectively the disclosure dynamics, firm risk, and investors' ambiguity aversion, within dynamic panel models. To investigate robustness of the estimates we have also included capital market ambiguity, firm size and stock liquidity indices in the model. The findings are consistent with existing theories. Firm risk and the capital market ambiguity have an increasing impact on the integrated information voluntary disclosure. However, the ambiguity at firm's level has decreased its voluntary disclosure. Likewise, a rise in ambiguity aversion (in-dependent of the ambiguity level), which makes investors more pessimistic about the firm's cash flows, makes the manager to increase the level of voluntary disclosure. Further, inertia in voluntary disclosure has been detected among the studied digital corporates. Depending on the magnitudes of the risk, ambiguity, ambiguity aversion, and the source of investors' ambiguity, the corporate managers decide on their voluntary disclosure policy appropriately.

The current study examined the effect of scaffolding through presenting examples and pictures on EFL learners’ vocabulary learning and retention.For this purpose, six research niquestions were posed and a quasi- experimental design was applied with two groups of learners who were selected as experimental groups. This research was carried out with a sample of 60 English students from Iran Zaban Institution. The data were collected using three instruments. Primarily, a standard test of Nelson which had 50 items was used to assess general proficiency of the learners for the purpose of their homogeneity. Then, in order to investigate the learner’s lexical knowledge before executing the scaffolding strategies used by examples and pictures, the researcher prepared a vocabulary test used as pretest. At the end of the treatment the students’ lexical knowledge was assessed by a posttest. Also a vocabulary test was used in order to measure their vocabulary retention after two weeks. The results indicated that employing examples helps vocabulary learning as well as retention. In addition, it was shown that using pictures helps both vocabulary learning and retention, and employing examples and pictures have almost the same effect on vocabulary learning. Finally, the results are discussed and compared with the previous ones, implications are explained, and some suggestions and recommendations are provided.

In the east of Pahanvar Ray plain, we come to a fertile area (Pishwa/Varamin plain) which has provided suitable conditions for human habitation since the formation of human settlements until today. Due to the location of this plain in the north of the central desert and the border between the two cultural domains of the northeast and the center, the environmental condition and suitable altitude, which are the main factors for the formation of permanent settlements, and the possible existence of extra-regional connections of this area with the neighboring areas, a wide survey was conducted in this area of ​​the plain. It was concluded that during this archaeological investigation, 61 ancient sites from the Sassanid era were found in the east of Varamin and south of Peshwa. It is most likely that Varamin is considered a part of Ray State and based on the available evidence, it is possible that it is the main center of Ray State as well. According to historical texts and archeological data, the state of Ray was one of the important areas of human settlement during the Sassanid period in Iran. Historical texts mention Ray in the Sassanid period, and the number of sites attributed to the Sassanid period in the geographical area of ​​Varamin has not been found until today. Despite this, based on the prominent geographical location of the Varamin region and the references of the historical texts to the Ray state, this region was probably one of the important regions of the historical period in Iran. In the present article, an attempt has been made to describe the historical geography of Ray State in the Sassanid period, while using the archaeological data of the Sassanid period of Varamin, to draw a part of the archeology and historical geography of Varamin in the Sassanid period.