The knowledge related to the methodology of the FIELD trial study as a type of intervention studies, yet for many of our researchers is not fully understood. The aim of the current study was a better understanding of conducting this type of research. FIELD trial studies are done on healthy individuals and aim to prevent. These types of studies such as clinical trials are performed on both individual and collective levels. One type of these studies is Community Intervention Trial which is usually done on a large scale population. FIELD trial study should be carried out in stages, such as the formulation of hypotheses, selection of the population (reference population, study population, and sampling), measuring the baseline variables (before conducting preventive intervention), random allocation of subjects to intervention and control groups, doing interventions and measuring outcome. The methodology of FIELD trial studies is very similar to clinical trials. The difference is that FIELD trials are conducted on healthy individuals and aim to prevent and also the sample size required to this type of study is relatively more, and these studies are usually time consuming and costly.

According to recent developments in computer science and applications of softwares in computation and simulation of complicated problems in various FIELDs of science, computer methods grow as a science production basis. Spatial and Temporal Variation of electromagnetic FIELD INTENSITY could be investigated through some simplifications like 2-dim space, thin wire assumption, spotted-source and distant FIELDs approximation. Finite differences method could be used to solving Maxwell’s equations by given boundary conditions in convergence limits. To comparison our solution by what is prospected, we use 2-dim structured grid in several examples.

Fifty six populations of sainfion (Onobrychis viciaefolia) were evaluated for responses to powdery mildew using randomized complete block design at Alborz research station, Iran, during two years. Results showed different degrees of disease severity index among the studied populations. During, 2008, Several populations such as Polycross-Karaj, Oshnaviah, 9262 (Karaj), 8199 (Tehran), 2399 (Karaj), Tehran (3001), Karaj (15353), North-Khorasan (3062), and Chaharmohal (8799) had disease severity index, lower than 25% which were regarded as tolerant to powdery mildew. The disease severity index of several populations such as Ardebil (20520), Karaj (9054), Ahar (20521), Bonab (20357), and Tabriz (2958), were in range between 25-50%, regarded as semi-susceptible. The rest of the populations with disease severity index more than 50%, nominated as susceptible. The evaluations were continued on selected populations for both disease and forage yield during 2009. There was significant differences between the populations for both of the traits for three successive cuttings. Forage yield of Tehran (3001) and Chaharmahal (8799) was higher than means of semi-susceptible and susceptible populations. Results implied that the last two mentioned populations and Oshnaviah could be considered as desired parents for developing synthetic varieties of the species.

Background: The High INTENSITY focused ultrasound (HIFU) is a noninvasive and effective technique for tumor ablation. Frequency and acoustic power are effective parameters for temperature distribution and the extent of tissue damage.Objective: The aim of this study was to optimize the frequency and acoustic power and to achieve appropriate temperature and thermal FIELDs.Methods: This analytical study was conducted in Kermanshah, 2014. Computer simulation was performed using MATLAB software (HIFU simulator toolbox). The KZK nonlinear wave equation was used to model sound propagation. The Bio heat equation was used to calculate the transient temperature in the liver tissue. Extracorporeal transducer was assessed over a frequency range of 2, 3 and 4 MHz and a power range of 50, 100 and 150 W.Findings: In 2 MHz frequency, the temperature in the focal point reached to 44.5oC, 55oC and 75oC for 50, 100 and 150-W power, respectively. In 3 MHz frequency and the mentioned powers, the temperature reached to 47.5oC, 67oC and 94oC, respectively. The temperature reached to 45.5oC, 55oC and 67oC in 4 MHz frequency, respectively. 2, 3 and 4 MHz frequencies with 150- W power and 3 MHz frequency with 100-W power induced considerable extent of thermal dose. Conclusion: 2-MHz frequency and 150W power can lead to more thermal dose in the same exposure time. These parameters can reduce treatment period and complications in larger tumors ablation.