فلزات سنگین از مناسب ترین شاخص ها برای بررسی آلودگی منابع خاک و آب هستند و به دلیل پایداری درازمدت در محیط زیست می باشند. هدف از پژوهش حاضر بررسی آلودگی فلزات سنگین در خاک کاربری های جنگل، مرتع، کشاورزی و مسکونی در آبخیز واز است. سپس با استفاده از نتایج غلظت فلزات کروم، منگنز، آهن، نیکل، مس، روی، آرسنیک، کادمیم، جیوه و سرب و با استفاده از شاخص های عامل آلودگی، درجه آلودگی، درجه آلودگی اصلاح شده، زمین انباشت، شاخص غنی سازی و خطر اکولوژیک کیفیت رسوب در کاربری های مختلف بررسی شد. نتایج نشان داد که کاربری شهری هم از نظر عامل آلودگی و هم از نظر شاخص تجمع زمینی دارای بیش ترین مقدار است و کاربری های کشاورزی، جنگل و مرتع به ترتیب در رتبه های بعدی قرار دارند. از نظر درجه آلودگی کاربری مرتع آلودگی بسیار کم، کاربری های جنگل و کشاورزی آلودگی متوسط دارند و کاربری مسکونی دارای آلودگی زیاد است. از طرفی شاخص درجه آلودگی اصلاح شده نشان داد که کاربری جنگل، مرتع و کشاورزی دارای آلودگی بسیار کم و کاربری مسکونی دارای آلودگی کم است. در حوزه آبخیز واز کاربری مرتع و تا حد زیادی کاربری جنگل از نظر شاخص های آلودگی دارای مقادیر پایینی بودند اما به دلیل حضور دام در مراتع این منطقه و همچنین توریستی بودن جنگل های این حوضه احتمال آلوده شدن خاک این کاربری ها در آینده وجود دارد. با توجه به اینکه این حوضه یکی از ورودی های دریای خزر در شمال کشور است، بنابراین نیاز است که اقدامات حفاظتی لازم برای منابع آب و خاک در حوضه مورد نظر انجام گردد.

Background and purpose: Soil contamination resulted from either natural or anthropogenic factors reduces environmental quality. The aim of this study was to evaluate the geoaccumulation, contamination factor, and principal component analysis indices to estimate topsoil contamination in Aran-Bidgol town.Materials and methods: 135 topsoil samples were collected from Aran-Bidgol town and the metal concentrations of Cd, Pb, Ni, Cu, and Zn in each sample were determined. The index of geoaccumulation (Igeo), contamination factor (CF), and principal component analysis (PCA) techniques were applied to determine the status and trends of soil contamination in this region. The inverse distance weighting (IDW) was then used to map these soil contamination indices.Results: The research found that the means concentrations of Cd, Pb, Ni, Zn, and Cu were 0.72, 11.41, 29.87, 48.59, and 14.82 mg/kg respectively; all exceeded the background values. Mean Igeo and CF of elements followed the order: Cu>Cd>Ni>Zn » Pb. The Igeo and CF maps showed higher values of Cd, Pb, and Zn in areas near industrial estates, brick kilns, and urban areas whereas higher levels of Cu and Ni occurred in urban and agricultural areas. According to the PCA index, two principal components were identified that Cu, Ni and Zn were highly loaded in PC1 and Cd and Pb occurred in PC2.Conclusion: Results indicated that the concentration of Pb and Cd are mostly affected by human activities, whereas Ni, Zn, and Cu contents are controlled by both anthropogenic and natural sources.

The study area is about 2000 km2 which is important in terms of agriculture, industry and residential complexes. For the purpose of evaluation, 241 samples of surface soil were taken based on systematic nested method from the land soils in the depth of 0 to 10 cm that were under agriculture, pasture and urban uses. The total concentrations of heavy metals of the samples were determined by an atomic absorption spectrometer following the extraction with 5N nitric acid. The results showed that the total amounts of lead, zinc, cadmium and copper in the soil of the studied area were 1.6, 2.0, 4.0, and 1.5 times higher than those in the soil of the natural background respectively. The total concentrations of iron, manganese, chromium, cobalt and nickel in samples were less than those in the background soil. Based on the contamination factor, in the most of samples, concentration of the iron, manganese, chromium, cobalt, nickel and copper were in low to moderate and Pb concentration in 10% of the samples was in high contaminated classes. More than 40 percent of the area was highly polluted with Cd. High levels of contamination factor for lead, zinc, cadmium and copper (Group I) were found in urban land area and contaminated soils with iron, manganese, chromium, cobalt, and nickel (Group II) were observed in agricultural and pasture lands. Overlaying the maps of contamination factors with those of land uses showed that the first group of heavy metals were mostly affected by human activities and the second group by parent materials.

Amount of fumonisin B1 in 46 corn samples which were collected preharvest, at harvest and post harvest stages (after drying, befor and after silage) from Golestan province in northern Iran was evaluated. The samples were milled using analytical Romer mill. Fumonisin B1 was extracted with methanol-water (80:20 v/v) solvent, purified by immunoaffmity columns (IACs) and converted to fluorescent derivatives by OPA (Ortho-phetaldehyde).The mycotoxin was quantified through high-performance liquid chromatography (HPLC) with fluorescence detector (Em=335 nm, Exi=440 nm). Standard curve was drawn between 0.3125-40 mg/ml using 6 fumonisin working standards. Validation of the method was estimated by Certified Reference Material (CRM). The percentage mean of recovery obtained using this method was 90.7 %. All samples were contaminated with fumonisin B1, the range of contamination varied from 261 to 6891 ng/g and the mean of contamination was 2658.35 ng/g. There was in significant difference on the contamination of samples at different sampling stages.

Nowadays, the fundamental role of having a purpose for life in physical and mental health has been confirmed. According to victor frankl, presence of a purpose in life gives life a meaning and increases resilience against pains and traumas. The importance of the purpose in life construct reveals the need for a reliable and valid tool to measure it. Crumbaugh and Maholick's purpose in life questionnaire is the first and one of the most applied tools for the assessment of life's purposefulness. The aim of this research is to determine the factor structure of purpose in life questionnaire. The questionnaire was administered on 206 students who were selected through random stratified sampling at Ferdowsi University of Mashhad. Exploratory factor analysis showed that there are two factors "comprehension" and "purpose" and this finding were confirmed by confirmatory factor analysis. Altogether results of this research showed factor validity of the purpose in life questionnaire with a two factor pattern

Human activities cause to the accumulation of heavy metals in soil. Soil pollution will significantly reduce environmental quality and affect human health. This study aimed to determine the concentration of some heavy metals (Ni, Pb, Fe, Zn, Cr and Cd) and evaluate the effects of Kerman steel industry on concentration of soil heavy metals. A total of 60 samples from the surface soil and a depth of 0-15 cm were collected at different distances from Kerman steel complex and analyzed with Atomic Absorption Spectroscopy (AAS). Some indices of pollution including Contamination factor (Cf), Pollution index (PI), Pollution load index (PLI), Pollution Intensity index (Ipoll), Potential contamination index (Cp) were calculated to assess the levels of soil contamination. The Pearson correlation, principal component analysis (PCA), hierarchical clustering analysis (HCA) was used to determine the origin of pollutants. The results were showed the trend of heavy metal concentration in the study area as Fe>Zn>Pb>Ni>Cr>Cd respectively. The maximum of studied indices was related to Pb and then Zn. Pearson correlation was showed that Zn with Cd and Pb with Cr had significant positive correlation. A PCA results of Cf index was stay Zn and Pb in the first cluster. In the other words, these two elements are more human origin. This study showed that the study area does not need to severe remedial action; however, continuous monitoring of environment is essential.

Introduction: Medical instrument contamination is one of the most important factor for infection transmission from patient to another patient. The different parts of medical stetoscope as a  potential source of transmission of harmful microorganism in nosocomial infection. The aim of this study was to determine the bacterial contamination in medical stethoscopes (ear pieces and diaphragm) as a one of the factor involve in transmission of nosocomial infections. Methods: The stethoscopes (n = 60) of the medical personal (Nurses, Physicians and student) of the educational hospitals in Semnancity, were cultured. In this study we investigated Both diaphragm and earpieces of stethoscopes and cultured separately. By means of a swab, which was wetted in sterile normal saline, sampling from earpieces and diaphragm performed and cultured on blood agar media. After 24h of incubation and by means of Gram's staining, .catalase test, culture on M.S.A and coagulase test. Results: Result showed that stethoscopes contaminated was 83% and 75% in diaphragm and earpieces respectively. Staphylococci coagulase negative Staphylococci coagulase positive and Bacillus were isolated from diaphragm and earpieces respectively. Conclusion: Finding above showed that stethoscope may be an important factor in the spread of nosocomial infections agents, So that a policy regarding cleaning stethoscopes with an effective disinfectant may be helpful in reducing nosocomial infection.