Approximation of pn by Hn

In this paper we introduce some bounds including Hn = ∑n k=1, (1/k), for pn, nth prime number. Then we observe that the Prime Number Theorem is equivalent with pn ~ nHn, when n tends to infinity

Molecular and phenotypic characterization of atypical enteropathogenic Escherichia coli serotypes isolated from children with and without diarrhea

BackgroundWe characterized 36 atypical enteropathogenic Escherichia coli (EPEC) serotypes isolated from children with and without diarrhea in Iran. Because the identification of atypical EPEC based on biochemical features is rather difficult and time consuming, we used a combination of three approaches, including a polymerase chain reaction-based method, culture adherence assay, and the restriction analysis of fliC gene (fliC-restriction fragment length polymorphism), to identify E coli serotypes.MethodsTo distinguish typical and atypical EPEC strains, the presence of EPEC attaching effacing A gene (eaeA) gene and EPEC-attaching factor (EAF) plasmid were analyzed. All E coli strains were identified based on the detection of the eaeA+, bundle-forming pili A gene (bfpA−), EAF− or eaeA−, bfpA+, EAF− profiles and the absence of stx (encoded for shiga toxin) gene as atypical EPEC.ResultsAll strains studied belonged to 5 atypical EPEC serogroups and 15 serotypes based on the virulence profiles. Of 36 atypical EPEC serotypes, 22 (61.2%) and 14 (38.8%) strains isolated from diarrheal and healthy cases, respectively. O142:H48 (19.5%) and O111:H21 (11.1%) serotypes were the most prevalent isolates, followed by serotypes O111: H− and O86:H48 (5.6% each).ConclusionsThe characteristics of the atypical EPEC serotypes from children with diarrhea were significantly different from those without diarrhea. The compilation of data on atypical EPEC strains presented here indicates the importance of a combined approach of conventional and molecular tests to study the virulence and epidemiology of EPEC serotypes in human subjects

Gender Differential in the Association of Body Mass Index and Abdominal Obesity with Prehypertension and Hypertension in Iranian Adults

*Objective:* The aim of this study was to determine the gender differential in the relationship of body mass index (BMI) and abdominal obesity with blood pressure (BP) and prevalence of hypertension (HTN) and prehypertension (Pre-HTN) among the adult population of Iran.

*Design:* A nationwide cross-sectional survey was conducted from December 2004 to February 2005. The selection was conducted by stratified probability cluster sampling through household family members in Iran.

*Subjects and Measurements:* Weight, height, waist circumference (WC), and systolic and diastolic BP of 45,082 men and 44,322 women aged 15-65 (mean 39.2) were measured. 

*Results:* The prevalence of HTN was 25.2% in men and 24.8% in women; and 50.1% of men and 39.1% of women were pre-hypertensive. WC and BMI were strongly associated with BP in both genders. Multivariate analysis revealed that both WC and BMI had the stronger association with HTN and Pre-HTN in men than women. Compared to men and women with normal weight, the multivariate-adjusted odds ratio (OR) (95% confidence interval) of HTN was 5.75 (5.13, 6.44) for men and 4.29 (3.95, 4.66) for women with BMI ≥ 30. The multivariate OR of prevalence HTN in men with abdominal obesity compared with men without was 3.76 (3.41, 4.22) and in women, 2.92 (2.73, 3.13).

*Conclusion:* These data indicate that both BMI and WC had the stronger association with HTN and Pre-HTN in men than women. 
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The role of discretionary accruals in earnings management: Evidence from Tehran Stock Exchange

Earnings management via discretionary accruals is a manager's instrument for changing stock holders’ expectations. The purpose of this study is to investigate the role of discretionary accruals in the earnings management of Iranian firms. There are two hypotheses associated with this study on the relationship between income smoothness and discretionary accruals and the proposed study is implemented on selected firms from Tehran Stock Exchange. The result of the first hypothesis indicates the relationship between earnings smoothness and discretionary accruals variables. It means that discretionary accruals (DA) leads to the converse relationship among discretionary accruals variation and current and future cash flow. The result of the second hypothesis indicates that the firms with high variation in Iran utilize more discretionary accruals compared with the firms with lower variation

Quality Variations of Biochar Generated from Wheat Straw During Slow Pyrolysis Process at Different Temperatures

Biochar has received great attention by many researchers recently due to its potential to improve soil fertility and immobilize contaminants and is proper as a way of carbon sequestration and therefore a possible carbon sink. In this work, a series of biochar were produced from wheat straw by slow pyrolysis at different temperatures (300, 400, 500, 600 and 700 ◦C) and their physicochemical properties were analyzed. Biochar yield, ash content, the amount of nutrients and other physicochemical properties in the all treatment of the raw material for the effect of temperature on the wheat straw biochar and to determine the best temperature pyrolysis temperature for converting wheat straw to biochar with agricultural usage. As temperature increased incrementally from 300 to 700◦C, biochar yield, total N content and organic carbon (OC) decreased while pH, EC, ash content and OC stability increased. The generated biochars production caused yields 28.34-58.32 % of feed mass, stable OC % 65.32-92.14 and pH 7.4-10.9. The maximal transformation of feed OC into biochar recalcitrant OC occurred at 500 ◦C. There were reductions in the amount of functional groups as pyrolysis temperature increased for wheat straw biochar. However, total acidity of the functional groups increased with pyrolysis temperature increased for wheat straw biochar. To produce agricultural-use wheat straw biochar, 300 ◦C should be is suggested in pyrolysis process and for carbon sequestration biochar 500 ◦C is recommended

Effect of NH3/methylaluminoxane/dodecylamine modifiednanoclay on morphology and properties of polyethylene/ clay nanocomposites prepared by in-situ polymerization

This study presents methods for treating a kind of nanoclay and investigates the effects of methylaluminoxane (MAO) exposure time and or dodecylamine (DDA) reflux time on in-situ polymerization of ethylene in the presence of nanoclay and examines the morphology and properties of the prepared polyethylene/clay nanocomposites. The results revealed that by increasing MAO exposure time productivity decreased. Modification of nanoclay by NH3/MAO led to formation of exfoliated structures. In treatment with NH3/DDA, the change in reflux time resulted in different structures. SEM demonstrated that the morphology of the nanocomposites strongly depended on the modification method and treatment time. Dynamic mechanical analysis indicated that the elastic modulus of the nanocomposites increased by increasing MAO exposure time. The nanocomposites treated with different MAO exposure times showed similar thermal degradation behavior. The nanocomposite modified under the condition of 24 h DDA reflux time indicated the lowest thermal decomposition temperature due to poor dispersion of nanoclay in the synthesized nanocomposite. The nanocomposites modified by NH3/MAO had higher degree of crystallinity compared to those modified by NH3/DDA, which could be attributed to the difference in dispersion level of the modified clays. A relationship between the rheological properties, weight fraction and dispersion of modified nanoclay was observed. The findings showed that the modification condition had a significant influence on the morphology and properties of the synthesized nanocomposites

Performance Evaluation of Return, Risk and Liquidity of Firms Newly Listed in Tehran Stock Exchange

It is essential to understand the behavior of initial offerings in comparison with other firms in different periods of recession and prosperity of stock market, considering three indicators of performance, i.e. return, risk and liquidity. The focus of this study is performance evaluation of newly listed stocks considering above indicators in different periods of recession and prosperity. For this purpose, 317 active firms which were not consistently inactive for three months or traded by March 20, 2006 were studied. Based on the suggested model, performance of the newly listed stocks was evaluated simultaneously based on three indicators of performance. Then, performance of the newly listed stocks was evaluated individually based on those three indicators. Through MANOVA, performance of the newly listed stocks was evaluated better than other stocks. Keywords: initial public offering, return, risk, liquidity JEL Classifications: G11, G3

Design and Validation of Brain-based Aesthetic Curriculum

The aim of the present study was to design and validate brain-oriented aesthetic curricula. The present study has analyzed qualitative content analysis method, deductive categorization system, and new and innovative international researches in relation to brain-based aesthetics. The field of research includes all printed and electronic sources. By sequential purposeful sampling method and through fish taking tools, information is collected and analyzed in three stages of open, axial and selective coding, and then the categories of the presentation model. In order to validate and evaluate the fit of the model, it has been provided to a number of specialists in planning, curriculum, neuroscience and educational sciences, and their corrective opinions have been applied in the final model after obtaining the Kappa Cohen agreement coefficient. The results showed that the categories with higher priority and high factor load in these elements were as follows: The target element includes: visualization in learning and strengthening the brain in all activities. Content element includes: description of the function of the cognitive skills of the brain, flexibility of the brain. The element of teaching-learning strategies includes: raising the level of motivation, providing opportunities for thinking. The environment element includes: happy environment, active learning environment, aesthetic environment. The element of evaluation includes: paying attention to individual differences, using continuous and practical techniques. Therefore, according to the agreement coefficient of experts, it can be said that the proposed model for designing curricula can be appropriate in some courses and at certain ages

Machine-learning approach for fault detection in brushless synchronous generator using vibration signals

In order to maintain continuous production and to avoid the maintenance cost increment in power plants, it is important to monitor the condition of equipment, especially the generator. Regarding the impossibility of direct access to rotating diodes in brushless synchronous generators, the condition monitoring of these elements is very important. Here, a novel fault detection method is proposed for the diode rectifier of brushless synchronous generator. At the first stage of this method, the vibration signals are recorded and feature extraction is performed by calculating the relative energy of discrete wavelet transform components. Multiclass support vector machine (MSVM) is used for classification, and the best mother wavelet and number of decomposition level are chosen based on classification performance. To enhance the performance of the classification, a modified sequential forward subset selection approach is included by which the best statistical features are selected. In this approach, besides selecting the best subset of statistical features, the classification parameter is tuned according to the selected subset to achieve the best performance. The result of the proposed method is eventually compared with those results of classification performance using conventional subset selection. Experimental results show that the proposed method can detect rectifier faults effectively

marital satisfaction according to spouse’s smoking status

Introduction: One of the key aspects of mental health is one’s overall health and lifestyle. Longitudinal studies have shown that dissatisfaction with life causes long-term health damage and increases mortality, suicide tendency, unintentional injuries, disability at work, and diseases such as those of cardiovascular nature. Amongst all forms of satisfaction, that of marital is of utmost importance. On a separate note, inhalation of cigarette smoke exposes passive smokers to many chemical and toxic carcinogens, and it can negatively affect the non-smokers present. Furthermore, in psychiatric counseling sessions, many women report that they hate smoking. If we can show that inhaling cigarette smoke in men can have an impact on marital satisfaction, it can increase the consistency of family foundations and have positive effects on the health and spirit of family members by informing families. Methods: In this study, 200 housewives, who had smoking husbands that smoked at home, were subjected to pre-determined conditions, alongside 200 housewives who had non-smoking husbands and were therefore not exposed to smoking by their husbands at home. They were divided into two groups and were assessed by Marital Conflict Questionnaire (MCQ). For a closer look at the level of marital satisfaction, the questionnaire results were divided into three subgroups which were marked as low, moderate, and good. Results: After calculating the total score of the questionnaire and statistical analysis, the results showed a higher rate of marital satisfaction in women who had non-smoking husbands compared to those who had smoking husbands and this difference was considered significant at P-value <0.001. Conclusion: Inhaling cigarette smoke in men in the family environment may seem to make a good impression on the smokers, but as the results of our study suggest, it also has adverse effects on marital satisfaction