Journal of School of Public Health and

Background and Aim: Coronary artery disease (CAD) and its complications at a low age are more serious and more progressive than at higher age. Because of this difference in the natural history of the disease as a function of age, this study was conducted to compare CAD risk factors between two age groups, namely people below and above 45 years old.

Materials and Methods: Two groups of 200 hospitalized CAD patients each, one below, and one above, 45 years old were selected by simple random sampling between 2005 and 2007. Two groups were similar with regard to dates and duration of hospitalization. The following data were collected from the patients' hospital files and analyzed using SPSS/Win: age, sex and marital status area of residence a history of smoking, diabetes, and hypertension a family history of early-onset cardiovascular disease (CVD) weight and height and lipid profile. The logistic regression test was used to compare the variables between the two groups.

Results: The following variables were found to be positively associated with CAD in the under-45 year group: smoking history (OR=2.54 p=0.009), a history of early-onset CVD (OR=3.15 p=0.009), low high- density lipoprotein cholesterol (HDLc) (OR=5.53 p<0.001), and high blood cholesterol (OR=3.96 p<0.006).

Conclusion: The most important coronary heart disease risk factors at a lower age are smoking, a history of early-onset CVD, low blood HDLc, and high total blood cholesterol.

Background and Aim: Breast and cervical cancer screening is considered a health promotion behavior, influenced by complex factors. The theory of planned behavior provides a useful framework for predicting and understanding the health behavior and designing appropriate educational interventions. Integrating this theory with self-efficacy will increase its predictive value. The objective of this qualitative research project was to understand the factors influencing the behavior of breast and cervical cancer screening of female-workers as a base for future educational planning.

Materials and Methods: This was a qualitative approach research based on the Integrated Model of Planned Behavior and Self-Efficacy. Seventy 20-45 year-old women working in industrial plants in Abbasabad, Pakdasht, selected by purposeful sampling with maximum diversity participated, in 10 groups of 7 each, in focus-group discussions, in which they discussed their experience regarding factors influencing the behavior of breast and cervical cancer screening. Data were collected and their validity, conformability, transferability and dependability confirmed. For data analysis the conventional method of content analysis was used.

Results: The female workers had a low knowledge and attitude concerning the behavior of breast and cervical cancer screening. Attaching importance to comments given by the family members, especially the husband, and preference of treatment to prevention of disease in the society at large were the subjective norms of the female workers. The most important barriers to participating in screening programs were lack of knowledge, depression, fatigue, embarrassment and fear of examinations, fear of being sick, poor quality of services and lack of attention to privacy in health centers, limited access to health centers, and costs of tests. The female workers had a low self-efficacy for planning and overcoming barriers. Most of them had not had screening tests and had no intention of doing their screening tests in the following three month.

Conclusion: The following measures are recommended: designing and implementing specific educational programs in workplaces for female-workers aiming at increasing their awareness and positive attitudes towards breast and cervical cancer screening designing and implementing educational/training programs for families, employers and planners to increase their knowledge and attitude and facilitating women's access to health centers in industrial estates.

Background and Aim: The aim of this study was to assess the adherence to anti-retroviral prophylaxis after occupational and non-occupational exposure to human immunodeficiency virus (HIV) in patients consulting the Voluntary Counseling and Testing Center (VCT) of Imam Khomeini Hospital, Tehran during the period 2008 to 2009.

Materials and Methods: In this prospective study, patients were selected, the required information about them was recorded, and adherence to anti-retroviral drugs (including Ziduvudin, Lamivudin and Efavirens) was determined based on self-report by the patients. Eighty-nine exposed patients were followed monthly for 4 months, and in the case of low-adherence (less than 95%) they were asked for the reason(s) for noncompliance.

Results: Of the 89 patients, 55 were men (61.8%) and 34 (38/2%) were women with a mean age of 30.16± 8.39 years 47 participants (52.8%) were single and 42 (47.1%) married 27 subjects (30.3%) were physicians, 35 (39.3%) nurses and 27 (30.3%) had occupations outside the healthcare system. From among the 36 subjects (40.5%) who stopped the treatment, 24 (27.0%) stopped it correctly (that is, when the serological test proved to be negative), while 12 (13.4%) did not stop it on a sound basis. Fifty-three subjects (59.6%) completed the prophylaxis. Adherence was found to be significantly associated with age and marital status (p<0.05).

Conclusion: The main reason for stopping the prophylaxis (a negative serological test result of the resource patient) was more pronounced than previous studies, which indicates the higher availability of the resource patient.

Background and Aim: There is evidence showing that increased inflammatory mediators and reduced serum levels of polyunsaturated fatty acids may be present in patients with neurodevelopment and psychiatric disorders, e.g.  attention-deficit/ hyperactivity disorder. (ADHD). The objective of this study was to determine the effects of dietary omega-3 fatty acid supplementation on hyperactivity, attention deficit, and serum inflammatory mediators in children with ADHD

Materials and Methods: This was an 8-week randomized double-blind clinical trial. The participants were 103 6 to12-year old children with ADHD receiving effective maintenance therapy, who were assigned randomly to receive either a daily omega-3 supplement (635 mg eicosapentaenoic acid and 195 mg docosahexaenoic acid (intervention group) or a placebo visually similar to the omega-3 capsules (placebo group). The serum levels of C-reactive protein (CRP) and interleukin-6 (IL-6) were determined at baseline and at the end of the period. In addition, the abbreviated 10-item Conners parent rating scale (CPRS) was completed for each child before and after the intervention. 

Results: The intervention brought about statistically significant reductions in the levels of CRP and IL-6 and a significant improvement in the CPRS score in the omega-3 group.

Conclusion: The findings indicate that dietary omega-3 fatty acid supplementation can have desirable effects on hyperactivity, attention deficit and inflammatory mediators in children with ADHD.

Background and Aim: Child growth disorders are a result of nutritional ignorance and lack of appropriate care and growth monitoring. This study was conducted to assess the effects of mothers' educational program based on the precede model on the prevention of growth retardation in 6 to12-month old children in the health centers of Shiraz city, Fars Province, Iran.

Materials and Methods: This quasi-experimental study included 120 mothers (60 cases and 60 controls) with a single exclusively-breastfed child under the coverage of health centers in Shiraz city, Fars province, Iran. A questionnaire was used to collect data on demographic characteristics and the precede model components (knowledge, attitude, enabling and reinforcing factors and maternal behavior). In addition, the children were weighed and their weights recorded. The mothers' educational intervention consisted of six 55 to 60-minute sessions. The questionnaire was completed by the case mothers before and 4 months after the intervention.

Results: The interventional educational program brought about statistically significant increases in the mean scores of knowledge (p<0.001) and attitude (p<0.001). Further analysis of the data also showed that the enabling (training sessions and using references) and reinforcing factors, as well as practice score of the mothers and the mean weight of the children in the case group improved significantly as compared to the control group (p<0.001).

Conclusion: The results of this study indicate that an interventional educational program for mothers based on the precede pattern had a positive effect in the prevention of growth retardation in the study population.

Background and Aim: Fleas are the most important ectoparasites of humans and domestic animals. Their bites are painful, usually accompanied with itching in addition, they transmit diseases such as plague, tularemia, and endemic typhus. The aim of this study was to identify species of fleas in the rural areas and animal farms in Boyerahmad

Materials and Methods: This study, conducted for 6 months, from April to September 2007, included 30 villages of the Boyerahmad District (30 ° 9'-31 ° 32 'N: 49 ° 57'- 50 ° 42'). To collect fleas, the common catch methods, such as fly paper, light trap, etc. were District, Kohgiloye-and-Boyerahmad Province, Iran.

used. The samples collected were kept in 70%-ethanol, and then, after clarifying and dehydration, were identified in the laboratory using valid keys.
Results: A total of 2435 fleas (54% males and 46% females) belonging to two families (Placida and Ceratophylidae), 4 genera and 7 species were collected. The most common species was Xenopsylla buxtoni (24.7%), followed by the dog flea, Ctenocephalides canis (21.4%), the cat flea, Ctenocephalides felis (18.5%), Xenopsylla astia (14.5%), Xenopsylla nuttalli (7.6%), Pulex irritans (7.2%), and N. fasciatus (6.1%). The fleas abundance (mean ± SE) in human and animal habitats was found to be  0.7±0.06 and 3.4± 0.2, respectively.  

Conclusion: On the whole, the flea species are quite diverse and abundant in the rural areas of Boyerahmad District in human and, particularly, animal habitats. This is a serious problem. Measures should be taken to control the fleas, particularly in rural areas.

Background and Aim: Omega-3 fatty acids can reduce inflammation in diabetic patients via special mechanisms. The objective the current study was to investigate the effects dietary omega-3 fatty acid supplementation on the serum levels of C-reactive protein (CRP), interleukin-2 (IL-2), and tumor necrosis factor-alpha (TNF-α) in type 2 diabetes patients.

Materials and Methods: This randomized double-blind placebo-controlled clinical trial was conducted on 57 subjects with type-2 diabetes. The participants were randomly assigned to one of 2 groups receiving either an omega-3 fatty acid supplement (containing 1584 mg eicosapentaenoic acid, 828 mg docosahexaenoic acid, and 338 mg other omega-3 fatty acids) or a placebo tablet (containing 2100 mg sunflower oil) for a period of 8 weeks.

Results: The serum TNF-α  and IL-2 concentrations decreased significantly in the omega-3 fatty acid group in comparison with the placebo group (in both cases, p<0.01). The intervention did not bring about any statistically significant changes in the serum CRP concentrations.

Conclusion: Considering the beneficial effects of omega-3 dietary fatty acid supplements on the 2 inflammatory biomarkers, namely TNF-α and IL-2, type-2 diabetes patients are recommended to consume such supplements or foodstuffs rich in omega-3 fatty acids, e.g., fish.

Data missing, which occurs for different reasons, is an unavoidable problem in epidemiological studies. It is quite widespread and, therefore, it is considered as a challenge in research design and data analysis by many methodologists. Complete case analysis is often used in studies with missing data however, this approach may result in inaccurate estimates and inferences due to bias associated with missing data. It is possible to obtain more accurate results through data repairing methods. Ordinary, simple strategies, such as single imputation methods, have drawbacks and limitations in practice. It has, however, been demonstrated that using modern imputation techniques can, despite their complexity, reduce bias dramatically in many situations, if used appropriately and properly. In this review, application of multiple imputations, as a novel technique for handling missing data in health and epidemiological research, is briefly discussed

Background and Aim: Vitamin D deficiency is highly prevalent in Asia, including the Middle East. Vitamin D deficiency has been found to have an inverse relationship with occurrence of type-2 diabetes mellitus (DM). In this study we assessed the vitamin D and calcium status in type-2 diabetic patients and compared it with that of healthy subjects in Tehran, Iran.

Materials and Methods: This cross-sectional study included 180 Tehrani individuals, including 95 DM patients, selected randomly from among the members of Iranian Diabetes Association, and 85 healthy subjects in Tehran, Iran. Age and gender were adjusted between the two groups. Serum levels of 25(OH)-vitamin D, calcium, phosphorous, and Parathormone (PTH), as well as weight, height and body mass index (BMI) were measured.

Results: The mean and SD age and BMI of the diabetic patients were 51.26 ± 11.18 years and 26.22 ± 9.30 kg/m², respectively the corresponding figures for the healthy subjects were 51.55 ± 13.39 and 26.26 ± 4.55. The prevalence of calcium deficiency was close in the 2 groups, it being 55.8% in the diabetic, and 57.0% in the healthy, subjects. The data also showed that while 26.3% of the patients suffered from a poor vitamin D status, only 18.6% of the healthy subjects had this problem.

Conclusion: Vitamin D deficiency is highly prevalent among both type-2 diabetic and healthy subjects and should be considered a public health and nutritional problem in Tehran city, Iran.

Background and Aim: Responsiveness is of extreme importance in every health system, especially for policy-makers and health managers. Responsiveness relates to how the health system responds to legitimate expectations of the patients regarding non-clinical aspects of health care. Furthermore, justice in an organization requires fair treatment of the patients on the part of the health personnel. In other words, organizational justice relates to how to treat the personnel so that they feel they are treated fairly. The objective of this study was to investigate the responsiveness of hospital as perceived by patients and nurses and the relationship between the responsiveness rate and organizational justice as perceived by nurses in the hospitals.

Materials and Methods: This was a descriptive-analytical study aiming at determining the correlation between responsiveness and organizational justice in 8 elected hospitals (4 private and 4 public) in Isfahan, Iran. The study population was patients and nurses. A total of 320 individuals (160 patients and 160 nurses), selected by stratified random sampling, participated in this study. Two questionnaires, namely the adjusted WHO Responsiveness Questionnaire (for patients and nurses) and the Equity Questionnaire (for nurses), the validity and reliability of both of which had been determined, were used to collect data. The software used for data analysis was SPSS

Results: The overall score (out of 4) of organizational justice was 1.9 0.77, while the mean score of responsiveness as perceived by the nurses and the patients was 2.32 0.54 and 2.48  0.58, respectively. There was no statistically significant difference between the 2 groups with regard to responsiveness, but there was a positive association between responsiveness and organizational justice as perceived by nurses (r = 0.2, p = 0.03).

Conclusion: The variables in the hospitals studied are generally at an intermediate level and there are no statistically significant differences between private and public hospitals. There is no difference in organizational justice between private and public hospitals, but responsiveness is higher in private hospitals as compared to public ones. Thus, the public sector needs to attempt to create more incentives in health professionals in the health sector in order to guarantee higher-quality services and better responsiveness.

Background and Aim: Diabetes mellitus is a widespread disease. Diabetes patients should be fully familiar with the different dimensions of this chronic disease and possess the skills required for self-management and self-care. They should realize that each patient is a different case. It is to be noted that promoting self-management behavior is an essential component of case management in type-2 diabetes mellitus. The objective of this study was to assess self-management behavior of type-2 diabetes patients in Isfahan, Iran and determine factors influencing it.  

Materials and Methods: This was a 6-month cross-sectional study conducted in 2011. The study population was type-2 diabetes patients consulting an outpatient diabetes center in Isfahan, Iran. The sample included a group of 350 patients selected by the continuous sampling method. The self-management behavior of the patients was assessed using a diabetes self-management instrument (DSMI), containing questions on 5 domains. The responses were rated on a 5-point Likert scale and SPSS software, version 11.5 was used for analyzing the collected data.

Results: The response rate was 88%. The majority of the patients were 50-60 years (55.52 ± 8.42) old and 54.3% of them demonstrated borderline metabolic control according to the World Health Organization criteria. Mean scores of self-integration, self-regulation, interaction with health professionals and other influential persons, self-monitoring blood glucose, and adherence to recommended regime were 33.67±6.36, 29.09±5.9, 27.08±4.81, 11.71±3.91 and 11.46±2.9, respectively. On the whole, the global diabetes self-management behavior seemed to be not quite desirable (the score was at an intermediate level). Further analysis of the data revealed that self-management behaviors (at 3 levels, namely, desirable, intermediate, and undesirable) had significant associations (p<0.001) with demographic (age, gender, marital status, education level) and health-related (duration of diabetes, diabetes-related diseases, diabetes complications, general health, type of treatment, family income, and serum HbA₁C level) variables. Self-management behavior had no association with disease history 

Conclusion: Empowerment of patients afflicted with diabetes and, more generally, non-communicable diseases, which are quite prevalent and on the increase, in the area of self-management at the individual and community level will be a vital step towards promotion of health of the population.

Background and Aim: Demographic, physical, social and psychological factors make breastfeeding and its maintenance complex. Despite extensive breastfeeding promotion programs, no progress has been achieved. As breastfeeding is a phenomenon embedded in culture and folk perceptions, identification of its key determinants is essential when designing policies and implementing programs.

Materials and Methods: In this qualitative study, data were collected from 35 health professionals through a 4-day group interview using a structured questionnaire (open-end questions). The participants were purposefully recruited from among the health professionals attending a 4-day breastfeeding promotion workshop.

Results: The determinants of breastfeeding were categorized into 2 main domains, namely, people's perception of breastfeeding phenomenon and approaches employed in its promotion. The former domain was described by beliefs, demographic characteristics, social variables, and indigenous theories, and the later by practice in the cultural and social context, policies, interactions and practical skills.

Conclusion: From the participants' perspective, misperceptions of people can determine the degree of success or failure of a breastfeeding promotion program. Our findings confirm that people's perceptions are deeply influenced by their demographic characteristics, folk theories and social variables. As regards the breastfeeding promotion domain, the barriers are social-cultural factors rooted in the local beliefs and folk theories. The participants listed the breastfeeding promotion determinants as lactation policies and health providers' performance related to their skill in effective communication with mothers. Our findings also indicate that wrong beliefs, maternal and child diseases, caesarian section, and mothers' employment were believed to be deterrents in promoting breastfeeding in the community and that pediatricians, obstetricians and other health professionals can play key roles in the field. Based on our findings, we can further conclude that the phenomenon of breastfeeding and its maintenance are deep-rooted in social structure and cultural diversity. When designing and implementing breastfeeding promotion programs, local variables and determinants should be taken into consideration. 

Background and Aim:  Shift work may induce adverse effects such as health problems on human life. The purpose of this study was to investigate shift work-related health problems and their associated risk factors among workers of petrochemical industries.

Materials and Methods: This cross-sectional study was carried out in 21 petrochemical companies affiliated to the National Petrochemical Industries Company, Iran. The study population consisted of 3580 workers (44.2% shift- and 55.8% day-workers). Data were collected on demographic characteristics, shift schedules, and health problems using anonymous questionnaires. Statistical analyses and modeling were performed using SPSS version 11.5.

Results: The mean age of the day-workers with a job tenure of 8.87±7.22 years and of the shift-workers with a job tenure of 8.22±7.02 years was 34.56±8.19 and 33.15±7.73 years, respectively. Analysis of the data showed that prevalence of health problems among shift-workers was higher than that of day-workers. Furthermore, based on multiple linear regression analysis, it was revealed that, in addition to shift-working itself, other variables such as long working-hours, type of employment, age, job tenure, education, and job title also had a role in creating problems.             

Conclusion: Although in the shift-working system the main risk factor associated with health problems among the workers is the work itself, there are also other risk factors, such as demographic and occupational variables.

Background and Aim: Female genital mutilation (FGM) comprises all procedures that involve partial or total removal of the external female genitalia for non-medical reasons.The World Health Organization has estimated that 100 to 140 million girls and women worldwide are currently living with the adverse consequences of FGM. Two of the major incentives for FGM are traditions and social pressure, and the practice is mostly carried out by traditional circumcisers. Not only FGM has no health benefits for girls and women, but it has immediate and long-term complications. The objective of this study was to determine the prevalence of female genital mutilation and factors associated with it among women consulting health centers in Ravansar City, Iran

Materials and Methods: A cross-sectional study was conducted on 348 women consulting 5 health centers in Ravansar City, Iran. Data were collected using a structured questionnaire and SPSS.16 was used for data analysis.

Results: The prevalence of FGM was 55.7% and the mean age of the women undergoing FGM was 9.2±14.2 years. The prevalence increased with age. Almost in all cases the operation had been performed by traditional local circumcisers. The data also showed that 96.2% of the mothers and 87.6% of the sisters of the subjects had also been mutilated. There were statistically significant associations between FGM and several independent variables as follows: the mutilated women's age (0.001) and education level (p<0.001) their mothers' education level (p=0.006) and their awareness of, and attitude towards, mutilation (p<0.001).

Conclusion: FGM is prevalent among Ravansar women. Religious leaders and health personnel should attempt to discourage FGM. Promoting public awareness of FGM and its undesirable consequences is essential. Research shows that if a community itself decides to abandon FGM, the practice can be eliminated rapidly.

Background and Aim: It is known that oxidative stress plays an important role in the pathogenesis of diabetes. Consequently, use of antioxidant for treating and preventing complications of this disease is believed to be beneficial. Considering the antioxidant effects of soy isoflavones, this study was initiated to determine the effects of genistein, one of the isoflavones in soybeans, on serum glucose, lipid profile, and paraoxonase activity in diabetic rats.                                                                                                           

Materials and Methods: Thirty-six male Sprague Dawley rats were divided randomly into three groups, in 2 of which diabetes was induced by intravenous injection of 60 mg/kg body weight stereptozotocine dissolved in a 0.05 mol/liter citrate buffer the criterion for diabetes was a plasma glucose level above 250 mg/dl. All the 3 groups were fed a standard diet for 3 weeks, genistein (95% purity) being added to the diet of one of the diabetic groups at a level of 600 mg/kg diet. Fasting blood samples from the tail were taken at baseline and at the end of the period for measuring glucose, lipids, and paraxonase activity. The statistical test used for data analysis and inter-group comparisons was ANOVA.

Results: Supplementation with genistein had no statistically significant effects on the serum paraxonase activity or glucose level, but it brought about significant decreases in the serum triglyceride and total, HDL- and LDL-cholesterol levels.

Conclusion: Genistein can potentially have a beneficial effect on diabetes-induced dyslipidemia

Background and Aim: To examine the association of diet and the risk of esophageal squamous cell carcinoma (SCC) in Kurdistan province.

Materials and Methods: This was a case-control study including 47 patients with esophageal SCC and 96 healthy controls. Dietary intake was assessed using a valid semi-quantitative food frequency questionnaire. Logistic regression analysis was run to estimate odds ratios and 95% confidence intervals.

Results: The controls had a significantly higher mean body mass index (25.3 vs. 20.4) and a higher level of education than the case group, while the latter had significantly higher records of tobacco consumption and symptomatic gastresophageal reflux. An independent protective effect was observed for the highest tertile of total fruit consumption (OR: 0.13, CI: 0.04-0.45, p-value=0.001). Within the fruits group, a significant inverse association was observed for bananas, kiwis and oranges (P for trends: 0.03, 0.02 and 0.01, respectively). The effect of total vegetable intake on esophageal SCC was not significant (OR: 0.66, CI: 0.23-1.87), although a reduction in risk was observed in the highest tertile of intake. With regard to other food groups we did not find a statistically significant association.

Conclusion: The results of the present study suggest an inverse association only between fruit consumption and esophageal SCC.

Background and Aim: Access to reproductive health information and services is a basic right for the youth. Lack of suitable educational/counselling materials about reproductive health can decrease effectiveness of educational programs. This study aimed to determine the premarrital reproductive health educational needs of the youth.

Materials and Methods: In a descriptive-analytical study a total of 450 young males and females were selected by stratified random sampling to participate in pre-marital counseling in Tehran. Data about pre-marrital reproductive health educational needs were collected using a questionnaire developed by the investigator, with a 5 degree-Likert scale. SPSS-15 was used for data analysis, the statistical tests being t-test, one-tailed ANOVA and chi-square.  

Results: Based on the Likert scale (1-5), felt need for reproductive health education was 3, it being higher among females (p<0.05). Both the males and females thought that what they needed most was education/counseling on healthy sexual relationship. The educational needs did not seem to be influenced statistically significantly by socio-demographic variables in either gender.

Conclusion: Based on the results of this study, it seems that the current educational materials are not sufficient for pre-marrital counseling. Comprehensive information on reproductive health, with particular emphasis on sexual relationship, should be included in the existing programs, so that the youth can begin a better, healthier married life.

Background and Aim: The first step in establishing a safety system is hazard identification.  If this is not done properly, the subsequent steps steps will not be done effectively either. Since any given identification technique often targets the hazards of one or two of the main elements of a safety system, it is not possible to identify all hazards by a single technique

Materials and Methods: This cross-sectional study was conducted to explore the available scientific literature aiming at finding practicable hazard identification techniques that can potentially determine the highest number (%) of hazards in a safety system. First five techniques were implemented and the number of identified hazards by each was determined, followed by calculation of the coefficient of hazard identification effectiveness for each technique. Using this approach two techniques in two different safety systems were tested

Results: The number of hazards identified using the hazard and operability analysis (HAZOP) technique, and, as a result, its coefficient of hazard identification effectiveness was the highest as compared to other techniques. Individually, the HAZOP and AEA techniques, used as primary hazard identification techniques, identified only 20-80% of all the hazards which could otherwise be identified if all identification techniques had been used.

Conclusion: The results show that the HAZOP technique can identify a higher number of hazards than any other technique. However, if used alone, this technique will probably identify only 40% of all the hazards. The important point is that selection of an appropriate technique plays an important role in identifying a higher number of hazards.

Background and Aim: Iron nanoparticles are broadly used in medical science, particularly in synthesis of fluorescence biomarkers, cancerous tumor therapy by hyperthermia, and as a contrast agent in MRI. Physical and chemical synthesis methods currently used to produce nanoparticles cause environmental contamination. Certain bacteria are capable of synthesizing significant amounts of iron nanoparticles, quite in conformity with the principles of green chemistry. The objective of this study was to isolate iron nanoparticle-producing magnetotactic bacteria from Arjin ore in Zanjan Province, Iran

Materials and Methods: Serial dilutions were prepared from the soil of iron ore and inoculated on a combined solid agar culture medium specifically used to isolate magnetotactic bacteria. This was followed, after incubation at 30 degree for a week, by transferring samples of colonies to special liquid culture media. After three weeks of incubation, the samples were examined by Gram staining, XRD and of scanning electron microscope (SEM).

Results: The existence of iron nanoparticles was confirmed by analysis of XRD graphs. Furthermore, scanning electron microscopy pictures proved the shape of bacteria and extracellular accumulation of iron nanoparticles produced by them.

Conclusion: Magnetotactic bacteria isolated from Arjin ore in Zanjan Province, Iran are capable of biosynthezing iron nanoparticles.

Background and Aim: The purpose of this study was to compare the two techniques of fault tree analysis (FTA) and Tripod-Beta using the analytic hierrarchy process (AHP) for choosing the preferred technique to be used in the analysis of grave accidents in a steel-manufacturing company.

Materials and Methods: This research project was carried out in three main phases.  In the first phase two disastrous accidents were sketched for analysis and, using the two techniques of FTA and Tripod-Beta, the causes for their occurrence were determined. In the second phase 7 criteria were chosen for comparing the two techniques. Finally, in the third phase, the two techniques were compared on the basis of chosen criteria, using AHP.

Results: The findings showed that the criterion for the number of accidents' agents with a priority of 0.435 had the highest priority, followed by quantitative ability, cost of analysis, time spending, and software need with a priority of  0.07,  0.059,  0.038,  and 0.036, respectively.

Conclusion: Considering all the chosen criteria, it can be concluded that the fault free analysis technique with a priority of 0.624 is superior to Tripod Beta technique with priority a priority of 0.35.