Hyrcanian forests are the only forests designated for commercial timber production in Iran. Ground-based skidding is the most common timber harvesting system used in these forests, but due to low road density (1-2m/ha), large parts of the forests are still inaccessible. To facilitate timber harvesting in the forest, it has been proposed to increase the road density up to 20 m/ha. The aim of this study was to incorporate the estimated skidding costs through a time study into existing transportation planning tool, NETWORK 2000 software package to help decision making on forest road building. This method was applied to Gorazbon district in Hyrcanian forests, where 244 links were built for analysis. The study used continuous time studies based on empirical data for this logging method. The resulted regression model is a function of skidding distance. The best solution found by NETWORK 2000 indicated that all proposed roads should be built to minimize the total skidding and road building costs.

Introduction: Social health and hygienic behaviors have a direct link with supply and distribution of safe sufficient water. Different diseases can be transmitted to man via contaminated drinking water, However using the common disinfectants such as chlorine and its derivatives, the disease causing microoganisums can be elminated. In this study, the methods of chlorination and their usage in supplying water to rural areas in Ilam in 2000 have been analyzed.Methods :This descriptive cross- sectional study covered whole the villages in Ilam province. Questionnaires on water supply systems in rural parts were used to collect the date.Results: Then, the data was, classified and analyzed. The results show that chlorination in 47% of the villages under coverage was manual, while in 53% of them hypochlorinators were used. The study also shows that 99. 1% of the villages under coverage used perchlorin 70% as the main disinfectant material. In addition, 96.4% of the villages enjoyed chlorination measurement evaluation records and 83.8% have a daily measurement of residual chlorine. 74.7%of these villages have optimum residual chlorine rate. More over, 86.6% of them have recorded unacceptable chlorine residual cares and reported then to the relevant organization.Discussion: As the health of community has a direct link to safe and hygienic water, an effective and creative appropriate management along with accurate organization could reduce the percentage of age of unacceptable chlorine residue to zero in the water supply system in rural and urban areas. Employing competent and trained staff, regular supervision of health experts who work in the health centers and public education of through mass media seems necessary to promote people's awareness of drinking water supply NETWORKs and water disinfection at unusual and critical situations.

Nano materials have unique antimicrobial properties. In this study the toxic level of two nanosilvers, with the commercial name of L-2000 and Ls-2000 was studied. The toxicity effects (LD50) and Maximum Allowable Concentration (MAC) of silver nanoparticles in Barbus grypus was calculated with intervals of 24 hours.According to static OECD standard method fishes were treated with 8 serial dilutions (in triplicate) of nanoparticles and daily mortality recorded after 24, 48, 72 and 96 hours, moreover MAC was calculated using Probit software. The results showed that LC50 96h of L-2000 and Ls-2000 in Barbus barbulus were 0.127 and.076 mg/lit respectively.Versus MAC of L-2000 and Ls-2000 in this fish was 0.013 and 0.006 mg/lit. The results showed that both L-2000 and Ls-2000 had severe toxicity in B.grypus but, Ls-2000 was more toxic. These nanoparticles cannot be used in water contained B. grypus.

Background: Childhood obesity is increasing worldwide and is an important risk factor for many chronic diseases. Obesity generally causes increase in body weight and must. be evaluated according to the standard values for the individual age and sex. Materials and Methods: This survey had 2 stages. At the first stage, 835 8-11 old girls were studied. Height, weight were measured and BMI was calculated. Iranian BMI reference, CDC 2000 and IOTF 2000 references were used to define obesity. When using Iranian or CDC references, the prevalence of obesity was defined as the percentage of children above the 95th percentiles of the BMI. When IOTF reference was used, the students who had a BMI more than the BMI equivalent to 30 at age 18 considered as obese. At the second stage of the study, all the obese students (according to Iranian - reference) considered as Case group (n = 134) and 134 Control girls with the normal weight (5th percentile £ BMI <=5th Percentile) were chosen randomly and obese children were matched with non - obese children by sex, age, school and Classroom. Parental BMI were calculated using self - reported height and weight. Mothers and fathers having a BMI> 30 Kg/m2 were identified as obese. Results and Conclusion: The prevalence of obesity among all the study samples (n=835) were 16%, 9.6%, 6.6% according to Iranian, CDC 2000 and IOTF 2000 references respectively and obese girls had significantly higher possibility of having obese parents than controls (P<0.02).The results of this study indicates that childhood obesity is increasing in Tehran.