This research is an estimation of the exchange rate between the US Dollar and the Iranian Rial, for the period between 1352 and 1387. Using ARDL method for hypothesis testing, and selecting the optimal model, the Mean Square Error (MSE) and Root Mean Square Error (RMSE) are used to test our hypothesis.The selection of the optimal model for prediction is based on the Purchasing Power Parity (PPP) theory and the Monetary Approach to Balance of Payment. The results of this study indicate that the PPP model is a more accurate indicator of the exchange rate, and is therefore preferred to the monetary approach.

In economics the rate of return on agricultural R& D is one of the important factors for investment decisions in agricultural sector. The R& D expenditure is the core variable for the productivity factor. In this study, at first the impact of agricultural research and human capital was estimated on productivity by Almon lag model and in the next step the rate of return for agricultural R& D was calculated. The result showed that the R& D in agricultural sector affects the productivity after 4 years and this effect will last for 3 years. The long term coefficient of agricultural R& D is 0.17 and the internal rate of return (IRR) was calculated up to 36% in productivity models of Iran during the period of 1979- 2008 (1358-1387). Therefore, it is suggested that the agricultural R& D expenditures should be increased to 2% of agricultural GNP.

Proper estimation of range improvement benefits increases their efficiency and prevents misusing the national budget. We collected reports on 25 range management projects, and studied the list of their costs and benefits. Ignoring costs of rangeland rest (88% of projects), investment interest (80%), and underestimating project period (56%), had resulted in false estimation of project benefits. Hence, we proposed a new approach for evaluating economics of range management projects. Nevertheless, further research projects are needed to clarify some sources of costs and incomes, and also to estimate ecological services of a range management project.

Background and Objectives: Burns are tragic events with considerable mortality rates. This study was conducted to analyze the spatial pattern of burns and identify the factors associated with the burn injuries in Mashhad, Iran. Methods: This retrospective cross-sectional study was conducted in patients hospitalized in Imam Reza Hospital Burn Center, Mashhad, which is the only referral burn center in the northeast of Iran. Spatial generalized linear models (Poisson and negative binomial) were used to model the association between socio-economic characteristics and the incidence of burn injury. Results: A total of 1044 acute burn patients (69. 9% male, 30. 1% female) were reviewed. Most of the burned patients were in the age group 20-29 years (41. 4%). The most common cause of burn injury was flame (64. 6%). The local test of spatial autocorrelation confirmed that the burns had cluster pattern in the central areas of the city and the worn-out urban texture was at higher risk of burns. The results of model showed that the percentage of worn-out urban texture (IRR =1. 007; 95%CI 1. 005-1. 008), literacy (IRR =0. 98; 95% CI 0. 95-0. 99), percentage of employed women (IRR =0. 96; 95%CI 0. 92-0. 99), unemployment rate (IRR =0. 92; 95%CI 0. 85-0. 99) and percentage of margination (IRR =1. 006; 95%CI 1. 005-1. 008) were associated with burns. Conclusion: Based on the findings, socio-economic and environmental characteristics are associated with the incidence of burn injuries in different areas. The results of this study could be used to design burn prevention strategies, especially in the high-risk areas and groups.

Let G be a finite group and let N be a normal subgroup of G. Suppose that IRR(G|N) is the set of the IRReducible characters of G that contain N in their kernels. In this paper, we classify solvable groups G in which the set C(G)={IRR(G|N)|¹N⊴G} has at most three elements. We also compute the set C(G) for such groups.