28 research outputs found

    GA-PSO-Optimized Neural-Based Control Scheme for Adaptive Congestion Control to Improve Performance in Multimedia Applications

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    Active queue control aims to improve the overall communication network throughput while providing lower delay and small packet loss rate. The basic idea is to actively trigger packet dropping (or marking provided by explicit congestion notification (ECN)) before buffer overflow. In this paper, two artificial neural networks (ANN)-based control schemes are proposed for adaptive queue control in TCP communication networks. The structure of these controllers is optimized using genetic algorithm (GA) and the output weights of ANNs are optimized using particle swarm optimization (PSO) algorithm. The controllers are radial bias function (RBF)-based, but to improve the robustness of RBF controller, an error-integral term is added to RBF equation in the second scheme. Experimental results show that GA- PSO-optimized improved RBF (I-RBF) model controls network congestion effectively in terms of link utilization with a low packet loss rate and outperform Drop Tail, proportional-integral (PI), random exponential marking (REM), and adaptive random early detection (ARED) controllers.Comment: arXiv admin note: text overlap with arXiv:1711.0635

    Predictive Value of Absent Septal q Wave in Patients with Significant Stenosis of Proximal Left Anterior Descending Coronary Artery

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    Aims: There is conflicting data about the predictive value of absent septal q wave in patients with significant stenosis of proximal Left Anterior Descending coronary artery. To clarify the exact role of this simple electrocardiographic sign we conducted this prospective descriptive study. Methods: Patients who were referred for coronary angiography in Milad Hospital between December 2008 and September 2009 were chosen randomly. Standard ECG was performed and reviewed for presence or absence of septal q wave, and then the coronary angiography was done and reported by another cardiologist. Results: Of 148 patients with absent septal q wave in ECG, 85 patients (57%) had significant stenosis of proximal LAD in coronary angiography. Statistical analysis showed that significant stenosis of proximal LAD could be predicted by absence of septal q wave in ECG with sensitivity of 59% and specificity of 47%. However, Kappa statistic (Kappa = 0.36) showed low agreement between them. Conclusion: Absence of normal septal q wave in ECG could be a low value predictor of coronary artery disease mainly significant proximal LAD stenosis

    Immunomodulatory effects of Ziziphora tenuior L. extract on the dendritic cells

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    Background: Ziziphora tenuior L. (Kakuti in Persian) is used in traditional medicine for treatment of gastrointestinal disorders as carminative and analgesic plant. The other usages of this plant are included treatment of diarrhea and nausea. Therefore in the present study we evaluated the immunomodulatory effects of the ethanolic extract of this plant on the dendritic cells (DCs). Results: Ziziphora tenuior L. extract significantly (p = 0.002) increased the level of surface expression of CD40 as an important co-stimulatory marker on DCs compared to the control. However this extract did not change CD86 and MHC-II molecules, so it could promote DCs phenotypic maturation. Treatment of DCs with the extract resulted in slightly increased of the production of (IL-12); however, this change was not significant. In addition, the ability of treated DCs to stimulate allogenic T cells proliferation and cytokines secretion was examined in the co-cuture of these cells with T cells in mixed lymphocyte reaction (MLR). Z. tenuior L. at the 100 μg/ml concentration inhibited the proliferation of allogenic T cells and also significantly (P < 0.001) increased the level of IL-10. Moreover, the extract at 10–100 μg/ml concentration caused slightly increase in IFN-γ production and decreased IL-4 cytokines but these changes were not significant. Conclusions: These findings indicated that Z. tenuior L. extract can modulate immune response by induction of CD40 expression on DCs and cytokine production; whereas it can inhibit T cell stimulating activity of DCs in high concentration. These findings possibly in part explain the traditional use of this plant in treatment of immune-mediated disorders. However future studies are needed

    The role of dimensions of perceived risk in adoption of corporate internet banking by customers in Iran

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    Abstract During the recent years, one of the issues considered by the banks in the ?eld of internet banking is the adoption of corporate internet banking (CIB) by corporate clients. The present article tried to examine the factors affecting adoption of CIB by corporate clients based on the perceived risk theory. The research hypotheses were tested using con?rmatory factor analysis and the results showed that there was a signi?cant relationship between all the risks and intent to adopt CIB by the corporate clients of the banks. The major factors decreasing the intent to adopt internet banking include performance, privacy, security, ?nancial, time, and social risks respectively. Based on the ?ndings of the present study and similar studies, a comparison was made between the importance of the dimensions of perceived risk in personal and CIB and suggestions were made for decreasing the effects of these signi?cant risks for the corporate clients to adopt CIB.Keywords Corporate internet banking Adoption of technology Corporate clients Perceived risk theor

    Investigating the Impact of International Sanctions on Performance Indicators of Tehran Stock Exchange with Industries Divided From 2010 to 2020

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    In this research, the impact of the impact of the international sanctions index on the performance indices of the Tehran Stock Exchange by industries, including mass production indices, banks, insurance, automobiles, investments, basic metals, rubber, cement, chemical, industry, petroleum products, pharmaceuticals, transportation, sugar And thanks, we have checked for the time period from 2010 to 2020. For this purpose, we have used the weekly data of the above variables and using the Multivariate Generalized Autoregressive Conditional Heteroskedasticity (MGARCH),   Dynamic Conditional Correlation Generalized Autoregressive Conditional Heteroskedasticity (DCC-GARCH) model. Based on the results of the research, the influence of the sanctions index with different intervals (1 to 29) on the performance indicators of Tehran Stock Exchange with different ARCH and GARCH intervals (1 to 20) was proved by obtaining significant coefficients of -0.098417 to 0.137398

    Protoscolicidal and immunomodulatory activity of Ziziphora tenuior extract and its fractions

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    Objective: To evaluate the scolicidal and immunomodulatory effect of the Ziziphora tenuior (Z. tenuior) extract and its fractions. Methods: Protoscolices were treated with six concentrations (3, 5, 10, 25, 50, and 100 mg/mL) of Z. tenuior extract and its fractions (ethanol, petroleum ether, ethyl acetate and chloroform) in periods of 10, 20, 30, 40, 50 and 60 min, and viability of protoscolices was evaluated using the 1.0% eosin. To examine the immunomodulatory effects of Ziziphora and its fractions on macrophage cells, the non-toxic concentration of extract and different fractions determined by MTT assay, and the Griess reaction was used to measure the level of nitrite as an indicator of nitric oxide by the macrophage cells in 10, 100 and 200 mg/mL in 24 h at 37 �C. Results: In this study, the Z. tenuior extract at 10 mg/mL concentration was able to kill all protoscolices during 20 min. By increasing the concentration to 25 mg/mL, the scolicidal time reduced to 10 min. Regarding the effect of different fractions of Z. tenuior, the ethanolic fraction showed the highest scolicidal activity. The extract demonstrated an inhibitory effect on the activity of macrophages and reduced nitric oxide production. Although the petroleum ether and ethanolic fractions of the extract reduced nitric oxide production, nevertheless, this effect was only significant at 10 and 100 mg/mL concentrations (P < 0.05). Conclusion: The Z. tenuior extract and its fractions were effective against protoscolices yet the effect of total extract was considerable. Our findings indicates that the extract and its ethanolic and petroleum ether fractions could have anti-inflammatory properties

    An Investigation of the Effective Factors on Foreign Direct Investment with Emphasis on the Optimal Tax Rate in Selected Countries (Spatial Durbin Model for Panel Data)

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    Foreign investment is the function of globalization in the economies. There are so important factors for absorbing it . Cheap and skilled labor, the degree of openness of the economy and policies, activities and actions that attract this type of capitals are most important factors. To achieve this goal, governments enter a competitive game and try to attract these investments with their policies. In this study, first using a dynamic optimization control model and developing a Ramsey model to determine the optimal taxation on foreign direct investment in a small open economy for Iran and selected countries and then investigate the effective factors on Foreign direct investment with emphasis on the role of taxes through spatial econometric method (spatial Durbin model) for panel data during the years 2000 to 2017. The results show that the optimal tax rate for attracting foreign investment for the countries under study is close to zero. The results of spatial estimation by Dhaver sine and Euclidean methods also confirm the spatial dependence of the variables affecting foreign direct investment

    Inhibition of Pro-inflammatory Cytokines by Ethyl Acetate Extract of Scrophularia striata

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    Purpose: To investigate the effect of ethyl acetate extract of S. striata on pro-inflammatory production by macrophages. Methods: Mouse peritoneal macrophages were cultured in solvent either alone or with 2 µg/ml lipopolysaccaride (LPS) with/without different doses of ethyl acetate extract of S. striata. Production of pro-inflammatory cytokines including interleukin 1β (IL-1β), tumor necrosis factor - a (TNF-a) and prostaglandin E2 (PGE2) were examined using ELISA. Results: Ethyl acetate fraction of S. striata in doses of 10, 50, 100 and 200 µg/ml significantly (p<0.05) inhibited pro-inflammatory mediators (IL-1β, TNF-a, and PGE2) production by LPS stimulated peritoneal macrophages. Conclusion: The anti-inflammatory effect of the extract on pro-inflammatory cytokines may ameliorate inflammatory diseases, possibly via an immunomodulatory mechanism

    اثر ضد توكسوپلاسمايي عصار ههاي اتانولي گياهان زنيان، افسنطين و غوزه پنبه در شرايط برون تني

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    چكيده مقدمه: توليد داروهاي ضد توكسوپلاسما با اثربخشي بالا و عوارض جانبي كم از اهداف مهم تحقيقاتي توكسوپلاسماست. يكي از گزينه ها، فراورده هاي گياهي است. هدف: اين مطالعه به منظور تعيين اثر كشندگي عصاره هاي گياهان افسنطين، زنيان و غوزه پنبه بر تاكي زوئيت هاي توكسوپلاسما در شرايط برون تني عاري از سلول انجام شد. 100 و 200 ميلي گرم/ ميلي ليتر عصاره هاي ،50 ، توكسوپلاسما گوندي اي با غلظت هاي 10 RH روش بررسي: تاكي زوئيت سويه 30 و 45 دقيقه به طور جداگانه مجاورت و سپس با بلودومتيلن قليايي رنگ آميزي ، افسنطين، زنيان و غوزه پنبه در مدت زما نهاي 10 شدند. درصد كشندگي عصار هها با تعيين نسبت تاكي زوئي تهاي مرده در مقايسه با كنترل تعيين شد. تمامي آزمايش ها به صورت سه گانه انجام شد. از روش زيست سنجي در موش براي تأييد 100 درصد اثر كشندگي عصار هها استفاده شد. داده ها با استفاده از و آزمون تعقيبي توكي آناليز شد. ANOVA آزمون هاي آماري 100 و 200 ميلي گرم/ ميلي ليتر عصاره افسنطين و 200 ميلي گرم/ ، نتايج: به طور كلي 100 درصد تاكي زوئيت ها در غلظت هاي 50 30 و 45 دقيقه كشته شدند. كمترين درصد كشندگي عصاره هاي افسنطين، زنيان و غوزه ، ميلي ليتر عصاره زنيان در هر سه زمان 10 4 درصد بود. به روش زيست سنجي در موش 100 درصد كشندگي عصار هها /63 ± 2/ 4 و 1 /30 ± 2/26 ، 19/6 ± 8/ پنبه به ترتيب 4 تأييد شد. نتيجه گيري: هر سه عصاره اثر كشندگي بر تاكي زوئيت ها داشتند. اين اثر براي افسنطين و زنيان از غوزه پنبه بيشتر بود. مطالعات بيشتر به منظور شناسايي تركيبات مؤثره عصاره ها توصيه مي شود. گل واژگان: افسنطين، توكسوپلاسما گوندي اي، زنيان، عصاره گياهي، غوزه پنب
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