Showing 10 results for Dehnavi
Volume 3, Issue 1 (6-2013)
Abstract
The aim of this research is to identify and rank the effective factors of employee transfer in BIPC Basparan petrochemical company through 1388-1390. Identifying and ranking the factors of the employees transfer in production units such as BIPC Basparan petrochemical company can be regarded as an effective step in reducing the turnover of skillful and elite employees. The research has applied and holistic approach and the research population include all employees of Basparan petrochemical company. In order to gather the criteria and indicators, two questionnaires have been used in two stages. At the first step, the reasons behind the employees transfer were identified by library and internet-based research, in addition to interviewing with the experts. At the second step, the questionnaire number 2 was exploited in order to make pair comparisons and eventually prioritizing the key factors affecting the employee transfer. After pair comparisons between standards, the importance levels of factors were identified. According to the results, the level of job satisfaction ranks first, followed by organizational commitment, empowerment, organization structure, organizational leadership, absence and lack of punctuality.
Ehsan Dehnavi, Seyed Omid Ranaei Siadat, Amir Sahebi, ,
Volume 5, Issue 2 (8-2014)
Abstract
β- Xylosidase from Selenomonas ruminantium (SXA) is one of the most important enzyme for the hydrolysis of cell wall hemicellulose. SXA has potential utility in industrial processes especially production of bioethanol from bagasse. However, this xylosidase lose activity drastically above 50 °C. Each monomer of this homotetramer has four free buried cysteine. It seems that cysteine 286 has no role in protein function. In this study, to investigate effects of free buried cysteine on protein thermal stability, Cys 286 was replaced with the same size amino acid, valine. The mutant and native protein have expressed in Pichia pastoris. Kinetic and thermostability parameters of mutant were compared with the wild type enzyme. While pH optimum, temperature profile and catalytic efficiency of recombinant mutant were be found similar to native enzyme, mutant showed about 65% increase in thermostability respect to the wild type at 55 ˚C. Our results showed that free thiol group of cysteine caused the destabilization. Moreover, hydrophobic side chain of valine could involve in a hydrophobic interaction to stabilize SXA. Elimination of a free cysteine enhanced thermal stability without changing the catalytic efficiency of the enzyme that could be very important for biotechnological applications.
Volume 9, Issue 6 (No. 6 (Tome 48), (Articles in Persian) 2018)
Abstract
The present article aims to investigate and compare the argumentative discourse of Abraham’s debates with Nimrod, Azar, Star-worshipers and Idolaters in the Holy Qur'an. To this end, at first, the Persian translations of Abraham argumentative discussions with the opponents have been identified and then they have been analyzed based on Pragmatic-dialectical approach.This approach is composed of two parts: the dialectical and the pragmatic section. According to this approach, each argumentative dialogue has four stages: confronting, opening, argumentative and concluding features. In fact, the protagonist goes through these stages to defend his standpoint and tries to persuade the antagonist. Considering Abraham’s debates with his opponents on the one hand, and pragma-dialectical approach other hand, two questions have been the focus of attention in this article:1. Are these four stages of pragma-dialectical approach and the ways of persuading the audience different in Abraham’s debates? 2. Are the speech acts used in these debates the same? The related hypotheses are: 1. these four stages of pragma-dialectical approach and the ways of persuading the audience are not different in Abraham debates. 2. The speech acts used in these debates are not the same.
Research methodology is descriptive- analytical. The translations of Abraham’s debates with Nimrod, Azar , Star worshipers and Idolaters in the Holy Qur'an have been extracted from Makarem (1378, 12387) and Husseini (1382) and then have been analyzed and compared. Out of 167 Ayahs that have narrated Abraham‘s story in the Holy Quran, 61 Ayahs show Abraham’s debates. According to these debates, 105 speech acts were studied in terms of argumentative stages (confronting, opening, argumentative and concluding) and also the frequency of speech acts according to Searle (1969) was identified.
The research findings showed that from 105 speech acts in the debates, 86 of them are of Abraham and 19 cases belong to the opponents. In addition, the study showed that the argumentative stages of Abraham debates vary in these debates. Abraham debate with Star worshipers is different from other debates in confronting and opening stages. In this way difference in opinion is hidden in confronting stage and gradually it becomes clear in the opening and argumentative stages. Furthermore, in confronting stage the standpoint is single sided .Convincing the idolaters and Star worshipers, Abraham has made use of a“dramatic method”. In the pragmatic section, frequency and type of speech acts used by Abraham are different in the debates. In addition, the current research showed that this approach should be appropriately modified if it aims to investigate the argumentative discourse of the prophets in the Holy Qur'an.
Zahra Fathi, M. Mashhadi Akbar Boojar, Ehsan Dehnavi, Reza Hassan Sajedi,
Volume 11, Issue 1 (Winter 2020)
Abstract
Abnormal angiogenesis is associated with various diseases such as solid tumors and metastasis, retinopathies, and rheumatoid arthritis. VEGF-A is the most important mediator of angiogenesis among all growth factors. The bioactivity of VEGF is mediated by two tyrosine kinase receptors VEGFR-1 and VEGFR-2 present on endothelial cells. VEGF signaling through VEGFR-2 is the major angiogenic pathway that leads to stimulation of endothelial cell ingrowths into the tumor. It comprised of an extracellular portion, a cytoplasmic portion, and a short transmembrane domain. The extracellular portion consists of seven Ig-like domains (D1–D7), of which the 1st to 3rd domains function as ligand-binding sites. In the present work, a soluble recombinant extracellular domain 1-3 of VEGFR-2 was expressed in Pichia pastoris to inhibit the VEGF-induced angiogenesis. The 975 bp DNA fragment containing extracellular domain 1-3 kdr, was designed according to the nucleotide sequence at GenBank and protein sequence at Swiss-Prot. The recombinant secretory expression vector (pPinkαHC/KDR1-3) was constructed and transferred into yeast by electroporation. The high expression transformants were identified through complementation of adenine auxotrophy and cultured. KDR1-3 was expressed under the induction of %1 methanol and confirmed by using SDS-PAGE and western blot techniques. After being purified by affinity chromatography using Ni-NTA resins, binding of expressed product to hVEGF165 was proved by two direct ELISA and ELISA receptor binding assays. The data showed that human VEGFR-2 extracellular domain 1-3 with eukaryotic protein structure, that there is no reported paper about, was successfully expressed.
Volume 12, Issue 3 (Autumn 2012 2012)
Abstract
The weak axiom of profit maximization (WAPM) is used to analyze the optimization behavior of 18 Iranian banks within 10 years (2000-2009). In general the banks in the Iranian economy can be divided into 2 groups, state and privately owned banks. Nonparametric nature of this test allows us to study the profit maximization behavior of the firms without the need for any assumption on functional form of underlying technology. The WAPM is checked under 2 assumptions: constant technology and nonregressive technological change. Although most of the banks violate the deterministic WAPM test, testing the stochastic WAPM with measurement error and believing in existence of at least 1 percent measurement error in data, show the behavior of the privately owned banks and one of the state owned banks is consistent with WAPM under nonregressive technological change assumption. Although the behavior of the state owned banks is consistent as well if one believes in 5 percent measurement error, the difference leads to this conclusion that performance of the state development policies and objectives by the state owned banks has been deviated from profit maximization behavior.
Volume 12, Issue 3 (12-2022)
Abstract
Customer Retention and maintaining customer relationships and preventing customers from Churn is one of the most important tasks of organizations in today's highly competitive markets. In this study, the issue of customer churn and customer retention strategies have been investigated. These issues have been studied through systematic literature review and from different angles such as the field of organization, degree of individualization of customer relationship management, customer segmentation, and selection of key customers, employee engagement and evaluation.
In addition, a model based on deep learning networks has been used to predict customer churn. As a result, a conceptual framework and model is created based on the existing literature in this field and then combined with the customer churn prediction model using deep learning networks. The results show that the use of deep learning in predicting customer churn is a very effective and efficient way to solve the problem of customer retention and customer churn. This approach is not only able to accurately predict which of the organization's customers are turning away from the organization and disconnecting from the organization, but also can accurately identify the factors and parameters affecting customer churn and bring very valuable insight for the organization.
Volume 15, Issue 62 (3-2019)
Abstract
The study of the evolution of literary schools and comparing the principles and characteristics of different schools is one of the important fields of research in the comparative literature.Meanwhile, the contrast between classicalism and romanticism in the theory of literary genre and their different approaches to this category, is very significant. The authors believe that there are both intellectual and social principles in these two schools that theory of the literary genre of the schools, in spite of the plurality or apparent differences, is based on these principles and a large part of the contrast between these two schools is also the result of the opposition of these principles.This research is based on an analytical-descriptive approach and want to explain the principles and foundations in the context of intellectual and social conditions, its impact on the theory of literary types and, ultimately, the comparison of these schools. The results of this research show that the theory of essentialism and different perceptions of the theory of mimesis including belief of fixed and unchanging laws of literary genre, the purity of literary genre, as well as the belief in the existence of hierarchy among literary genre and the superiority of types of narratives such as tragedy and epic ,is the basis for the formation of the general principles of the theory of classical literary types of classicalism. In contrast , the components such as historicism, attention to the genius of the poet in the creation of literary work and the tendency toward individuality has led to the formation of a new theory of genres in the romanticism which it is based on the rejection of rules governing literary genre, the combination of existing literary genre, and the consideration of other literary forms, especially the lyric literature , novel, and the creation of new genre.
Volume 21, Issue 3 (5-2019)
Abstract
This study was designed to investigate the effects of physical forms and hay contents of diets on gene expression of insulin-like growth factor (IGF) I and II in rumen epithelium of Holstein calves. Twelve male calves were assigned to 4 treatments: ground (GR), texturized (TX), pellet (PL), and ground+10% forage (GF). Calves were weaned on day 50 of age and then slaughtered on day 70 after birth. Rumen epithelial tissue samples were immediately collected for quantification of mRNA abundance. Results indicated that only IGF I expression was influenced by the dietary treatments. A significant (p<0.05) correlation between IGF I expression and each of histological parameters denoted as length of rumen villi and diameter of keratinocyte layer was observed. No significant correlation between IGF II expression and rumen histological parameters was found (p>0.05). Regarding the results, higher IGF I expression in PL and TX treatments despite the low growth rate might be due to the challenging condition of developing rumen in calves. In fact, the rumen tissue attempted to maintain rumen pH at least by induction of a higher IGF I expression.
Volume 22, Issue 4 (6-2020)
Abstract
The objective of this study was to investigate the physiological responses and biological yield of black cumin (Nigella sativa L.) to nitroxin biofertilizer and chemical nitrogen fertilizer in the form of urea under different irrigation regimes. A split plot experiment was conducted on the basis of randomized complete block design with three replications. The main factor included four irrigation regimes (i.e., weekly from emergence to harvest and withholding from blooming to maturity, flowering to maturity, and the start of seed formation to maturity) and sub-factor included five levels (i.e., no application of fertilizers, 80 kg N ha-1, 40 kg N ha-1, combination of 40 kg N ha-1+nitroxin biofertilizers, and nitroxin biofertilizer). Application of 80 kg N ha-1 under full irrigation and the combined application of 40 kg N ha-1 and nitroxin under all withholding irrigations produced the highest glycinebetaine, polyphenol oxidase and catalase enzyme, total chlorophyll, and biological yield. Withholding irrigation from the blooming stage and also the application of 80 kg N ha-1 resulted in the highest concentration of malondialdehyde. In combined application of 40 kg N ha-1 and nitroxin, polyphenol oxidase, proline, and soluble protein were at the highest levels. Generally, the combined application of 40 kg N ha-1 and nitroxin increased the activity of the antioxidant enzymes and the compatible osmolites accumulation under all withholding irrigation treatments and thus decreased the negative effects of drought stress on black cumin, resulting in increased biological yield.
Volume 23, Issue 1 (1-2021)
Abstract
Salinity is one of the most important factors limiting plants growth and production in irrigated agriculture. The natural potential of salt tolerant plants like Kochia could be exploited through legume-containing intercropping systems as an effective strategy in mitigating the increasing salinity crisis.This experiment used split plots based on a randomized complete block design with three replications, in 2016 and 2017, at the Iranian National Salinity Research Center, Yazd, Iran. Water salinity was considered as the main factor (EC= 4, 9, and 14 dS m-1) and the cropping system was considered as subfactor with seven levels including sole cropping of Kochia (Kochia scoparia), Sesbania (Sesbania aculeate), and Guar (Cyamopsiste tragonoliba) and their possible dual and triple intercropping systems. The highest absorbed light was observed in triple intercropping and the total forage yield in triple intercropping was increased by 5% and 4.1% at 4 and 9 dS m-1 salinity, respectively, compared to that in Kochia sole cropping, while it decreased by 1.5% at 14 dS m-1.The Land Equivalent Ratio (LER) values ranged from 0.99 to 1.33. The total crude protein yield in triple intercropping was increased by 55.8 to 66.3% as compared to Kochia sole cropping. The NDF (Neutral Detergent Fiber) and ADF (Acid Detergent Fiber) were decreased by 7 to 22% in various intercropping systems. Considering increased forage quantity and quality, mainly through decreasing NDF and increasing Dry Matter Intake (DMI) levels, cultivation of Kochia within triple intercropping systems can be recommended instead of Kochia sole cropping.