Analysis of factors impacting on the competition of Iran’s air transport industry based on Porter’s Five Forces Model

Several factors play a role in an industry which may in turn involve threatening or survival of economical firms. Competition is one of the most important factors that its impact and role have been realized in industry management and economic firms. Under today’s competitive conditions, to maintain and expand the activities, economic firms are required to pay close attention to planning and strategic readiness. One of the areas of industry in Iran which needs to be analyzed regarding effective factors on competition is air transport industry. Accordingly, the current research tries to analyze factors impacting on the industry using Porter's five forces model. According to this model, an industry is affected by five competitive forces and these forces determine the state of competitiveness and profitability of an industry: entry of new investors, threat of substitutes, bargaining power of buyers, bargaining power of suppliers, and rivalry among existing competitors. The strongest force or forces play a major role in the firm’s strategies. In the current study, questionnaires, interviews, library studies and documents have been used for data collection. The statistical population of the research consists of managers (Senior, middle, executives), six airlines operating in domestic and international lines (Iran Air, Air Tour, Mahan Aseman, Kish Air and ATA). Analyses were carried out using Friedman test, t-test, exploratory factor analysis, and Kolmogorov-Smirnov test by means of SPSS. The results show that the most effective force on competition in Ian’s air transport industry is the bargaining power of suppliers, and the least effective force is the threat of new entrants. Also, the effectiveness degree of other forces, from the second to the fourth is the competition between existing competitors in the industry, the bargaining power of buyers, and the threat of substitute services, respectively.   Keywords: Strategic Management, Competitive Strategy, Porter's Five Forces model, Air transport industry.

Synergistic effect of pulsed electromagnetic fields and saffron extract on osteogenic differentiation of bone marrow mesenchymal stem cells

Introduction: Pulsed electromagnetic fields (PEMFs) are usually used to treat non-union fractures. Saffron is a medicinal plant with various pharmacologic effects. In the present study, the synergistic effect of PEMF and saffron aqueous extract on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was evaluatedMethods: BMSCs were isolated from rat femur. After purification, the cells were divided into four groups including control group (did not receive any treatment), saffron alone (800 μg/mL), PEMF alone (50 Hz, 3 times a weak, 2 hours for every time, for 2 weeks), and saffron plus PEMF. Cytotoxicity was measured using MTT assay. After calculating the IC50 value for saffron extract (1.5 mg/mL), a lower concentration (800 μg/mL) was combined with PEMF. The differentiation of each cell group was evaluated using alkaline phosphatase (ALP) enzyme activity, alizarin red staining and reverse transcribed polymerase chain reaction (RT-PCR) method.Results: Saffron aqueous extract decreased dose-dependently the cell viability but the PEMF had not any significant effects on cell viability. The PEMF, saffron extract and their combination increased the ALP activity on day 10 but the increase was significant in synergist group. Alizarin red staining showed that mineralization groups were higher at day 14. RT-PCR results demonstrated that on the day 14 the group treated with both PEMF and saffron expressed osteogenic genes.Conclusion: Saffron extract combined with PEMFs could promote osteogenesis at the initial stage (the commitment of undifferentiated mesenchymal stem cells into osteoblast), hence, its usage might be beneficial in these patient

Physicochemical Properties of Heavy Metals and Aflatoxin Levels in Sesame Oil: A Review Study

Introduction: The present study aimed to review the articles on determining the physicochemical properties of sesame oil in terms of the levels of heavy metals and aflatoxins without geographic restriction. Methods: Literature review was performed via searching databases such as Google Scholar, Pub Med, Science Direct, and SID. Based on properties such as iodine value and fatty acid profile, sesame oil has been reported to be highly unsaturated. In addition, the most important unsaturated fatty acids include oleic acid and linoleic acid, which constitute80-84% of the fatty acids found in sesame oil. The key feature of sesame oil was resistance against oxidative damage despite its high unsaturated fatty acid content. The oxidative stability of sesame oil is caused by the presence of gamma-tocopherol, lignans, and antioxidants (e.g., sesamol, sesamin, and sesamolin). Results: According to the reviewed articles, total aflatoxin level in sesame oil was less than the recommended limit by the European Union(EU) (20 μg/kg), with the exception of the study by Amin et al. (2010), in which total aflatoxin level was reported to be higher than the EU limit. In the reviewed studies, arsenic and lead levels were below the recommended EU limit (0.1 mg/kg). Additionally, the levels of copper and iron were reported to be below the national standard level in Iran (0.4 and 5 mg/kg, respectively). Conclusion: Considering the beneficial properties of sesame oil and its high degree of unsaturation, it is recommended that the levels of heavy metals aflatoxins be monitored regularly to consume this healthy vegetable oil

Efficiency measurement of cloud service providers using network data envelopment analysis

An increasing number of organizations and businesses around the world use cloud computing services to improve their performance in the competitive marketplace. However, one of the biggest challenges in using cloud computing services is performance measurement and the selection of the best cloud service providers (CSPs) based on quality of service (QoS) requirements (Duan, 2017). To address this shortcoming in this article we propose a network data envelopment analysis (DEA) method in measuring the efficiency of CSPs. When network dimensions are taken into consideration, a more comprehensive analysis is enabled where divisional efficiency is reflected in overall efficiency estimates. This helps managers and decision makers in organizations to make accurate decisions in selecting cloud services. In the current study, variable returns to scale (VRS), the non-oriented network slacks-based measure (SBM) model and input-oriented and output-oriented SBM models are applied to measure the performance of 18 CSPs. The obtained results show the superiority of the network DEA model and they also demonstrate that the proposed model can evaluate and rank CSPs much better than compared to traditional DEA models

Freethinking: development in thinking status

A note on how to promote freethinkin

Choroidal Thickness and Hemoglobin A1c Levels in Patients with Type 2 Diabetes Mellitus

Purpose: The aim of this study was to assess the correlation of hemoglobin A1c (HbA1c) levels with choroidal thickness in patients with type 2 diabetes mellitus (DM) using spectral domain optical coherence tomography (SD-OCT). Methods: In this prospective case series, 180 eyes from 90 patients with type 2 DM were classified into three study groups based on HbA1c values: group 1 included patients with good glycemic control (HbA1c ≤ 7%), group 2 included patients with moderate glycemic control (HbA1c between 7% and 8%), and group 3 included patients with poor glycemic control (HbA1c ≥ 8%). Additionally, 50 eyes from 25 non-diabetic subjects were enrolled to group 4 as a control group. Sub-foveal, nasal, and temporal choroidal thickness were measured and compared. Results: Mean central, nasal, and temporal choroidal thicknesses in diabetic patients (247.80, 238.63, and 239.30 μm) were significantly less than non-diabetic healthy subjects (277.56, 262.92, and 266.32 μm). Additionally, mean central, nasal, and temporal choroidal thickness values in group 4 (277.56, 262.92, and 266.32 μm) were significantly greater than the corresponding values in group 2 (248.34, 237.55, and 236.45 μm) and group 3 (239.81, 234.62, and 233.94 μm), but was not significantly different from corresponding values in group 1 (259.46, 246.12, and 251.00 μm). Conclusion: HbA1c values have a significant correlation with choroidal thickness in diabetic patients, and better glycemic control with HbA1c ≤ 7% may prevent choroidal thinning

The Evaluation of Aflatoxin Contamination in Various Foods in Iran: a Review

Introduction: Aflatoxins are secondary fungal metabolites produced by Aspergillus fungi, in particular Aspergillus flavus, Aspergillus nomius and Aspergillus parasiticus. Aflatoxins have undesirable effects on human and animal health and lead to various diseases, including liver disorders. Four main types of aflatoxin are B1, B2, G1 and G2, and aflatoxin M1 and M2 are metabolites derived from aflatoxins B1 and B2. Materials and Methods: In this paper, studies on aflatoxin contamination in different foods were investigated. Keywords for related articles include: Aflatoxin, Iran, Incidence, Food, Oil, Milk and Dairy Products. Articles were obtained from SID, Science direct, PubMed and Google scholar databases. Abstract of all related articles were reviewed and finally, articles which mentioned to the amount of aflatoxin were selected.Results: Results showed the presence of aflatoxins in most of the tested food. In most studies conducted on milk and various dairy products, the level of aflatoxin was higher than the recommended level set by the Institute of Standards and Industrial Research of Iran and the European Union. Conclusion(s): Practical management and control strategies are necessary for assurance of the safety of consumers regarding aflatoxin residue in different foods in Iran

Clinical outcomes and complications of treatment with supraflex stent in patients with coronary artery disease: One year follow up

Cardiovascular disease is one of the most important causes of morbidity and mortality in the world. Prevention is often a percutaneous coronary intervention. The new generation of stents is the Sirolimus Eluting Stent. The current study was aimed to investigate the clinical outcomes and complications of treatment with supraflex stent during one year follow up in patients with coronary artery disease. This cross-sectional study was performed on patients with myocardial ischemia who were candidate for angioplasty between 2017 -2018 in Imam Reza Hospital, Mashhad, Iran. Patients were followed for four primary end points including Target lesion revascularization (TLR), stent thrombosis (ST), myocardium infarction (MI) and cardiac death (CD) for one year. Descriptive data were analyzed by Freidman at a significance level of 0.05. A total of 287 patients were enrolled in the study. There was no TLR, MI, ST and CD records in the one month follow up. Six months follow up demonstrated three TLR patients and three MI patients, but no ST and death were reported. After one year follow up, three cases of CD and four ST cases were found in patients treated with supraflex stent. Based on the Freidman test, the highest rate of TLR was revealed in a six-month follow-up when comparing with onemonth and twelve-month follow-up (p = 0.05). No significant relationship was found between the other cases. The most common complications associated with supraflex stent were TLR and MI in six-month follow-up. The most likely occurrence of CD and ST were found in one year follow up

One-step versus two-step screening for diagnosis of gestational diabetes mellitus in Iranian population : A randomized community trial

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