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Showing 7 results for Yadollahi
B. Shareghi , E. Yadollahi , A. Rabie ,
Volume 9, Issue 1 (Winter 2018)
Volume 9, Issue 1 (Winter 2018)
Abstract
Aims: Proteinase K is an extracellular endopeptidase, which is secreted by Tritirachium album Limber and belongs to the serine endopeptidase class. This enzyme is extensively applied to protein-related studies. The present study aimed at evaluating the effect of urea, guanidine hydrochloride (GnHCl), and organic solvents on the kinetic activity of proteinase K enzyme.
Materials and Methods: In this experimental study, kinetics studies were performed, using UV-Vis spectrophotometer on different concentrations of substrate, urea, and GnHCl at 40˚C and pH 7.4.
Findings: Urea decreased the Vmax and Km of enzyme at 1 and 2molar concentrations, but at higher concentrations such as 3 and 4molar, it increased enzyme activity. GnHCl had an inhibitory effect on the enzyme activity, resulting in a decrease in Vmax and Km in 1, 2, and 3molar concentrations and acted as an uncompetitive inhibitor. Organic solvents including methanol, ethanol, and isopropanol had activatory effect at low concentrations and inhibitory effect at high concentrations on the kinetic activity of proteinase K enzyme.
Conclusion: Urea has an inhibitory effect at low concentrations and an activatory effect on the activity of the enzyme at a concentrations above 2molar, but GnHCl has an inhibitory effect at all concentrations and can be used as an enzyme inhibitor. The effect of organic solvents including methanol, ethanol, and isopropanol on the activity of the proteinase K enzyme depends on their volume/volume percent; they cause enzyme activation at low percentages, but have inhibitory effect at high percentages, so that activates methanol below 30% and isopropanol below 50%.
Materials and Methods: In this experimental study, kinetics studies were performed, using UV-Vis spectrophotometer on different concentrations of substrate, urea, and GnHCl at 40˚C and pH 7.4.
Findings: Urea decreased the Vmax and Km of enzyme at 1 and 2molar concentrations, but at higher concentrations such as 3 and 4molar, it increased enzyme activity. GnHCl had an inhibitory effect on the enzyme activity, resulting in a decrease in Vmax and Km in 1, 2, and 3molar concentrations and acted as an uncompetitive inhibitor. Organic solvents including methanol, ethanol, and isopropanol had activatory effect at low concentrations and inhibitory effect at high concentrations on the kinetic activity of proteinase K enzyme.
Conclusion: Urea has an inhibitory effect at low concentrations and an activatory effect on the activity of the enzyme at a concentrations above 2molar, but GnHCl has an inhibitory effect at all concentrations and can be used as an enzyme inhibitor. The effect of organic solvents including methanol, ethanol, and isopropanol on the activity of the proteinase K enzyme depends on their volume/volume percent; they cause enzyme activation at low percentages, but have inhibitory effect at high percentages, so that activates methanol below 30% and isopropanol below 50%.
Volume 10, Issue 1 (7-2020)
Abstract
This paper focuses on the issue of decision making in context of uncertainty and in particular on decision making in innovation and knowledge-based Firms. Decision making in uncertain conditions has many complications that make it difficult to rely solely on analyzes and common models in decision making. Meanwhile, the need to consider alternative methods, especially in the real environment of decision making, is felt. In this research, with a descriptive approach, the model of this type of decision is specifically defined in knowledge-based firms with a quantitative method and structural equation modeling. Statistical analyses were performed on 320 researcher-made questionnaires containing 77 items. Smart PLS software was used for modeling. The obtained model shows that time and information categories play a significant role in creating uncertainty. This uncertainty ultimately leads to the decision-makers' reliance on intuitive decision-making. Underlying conditions and interventions include environmental turbulence, rivals, market changes, technological changes, changes in environments, experiences, education, curiosity, and patterns of mental patterns effect on intuitive decisions that themselves include improvements in speed and accuracy of decision making, creativity, satisfaction and performance of the company.
Volume 11, Issue 4 (3-2022)
Abstract
The importance of this study is that as decision making in entrepreneurship is instantaneous, cognitive biases will have a direct influence on the decision making process and consequently, on failure and success of the entrepreneurs and their businesses. The current study has been conducted with a qualitative approach and the purpose of reducing the experience of failure in early stage entrepreneurs and enhancing entrepreneurial decision making will study and evaluate the mental models of national excellent entrepreneurs and the positive and the negative effects of cognitive biases on the decision making process of the entrepreneurs. Therefore, it is important to emphasize this issue. Our statistical sample consists of 11 national excellent entrepreneurs who have experienced the failure at least for once. The data collecting tool was semi structured interview with entrepreneurs in person or on the phone. The analysis of data was done in two phases. The role of the biases in the first and the second stage of the business life cycle is studied. Eventually, the result of the study is classifying entrepreneurs’ cognitive biases in four groups including: the main biases, motivators, common biases, and disincentive biases of entrepreneurship. This classification is done based on the experiences of entrepreneurs about cognitive biases.
Volume 16, Issue 2 (3-2014)
Abstract
Red fleshed apples have high levels of anthocyanins in their flesh. Iran enjoys a large variety of these apples due to its location in Central Asia. In the present study, 20 genotypes including eight Iranian red fleshed and 12 commercial Iranian and foreign apples were selected for the study of genetic diversity of red fleshed apples. We used a set of 11 microsatellite markers (SSRs) to determine genetic diversity and the linkage between these SSRs and red fleshed color. Seven SSRs were amplified and revealed adequate performance. On the whole, 56 alleles were detected ranging from 3 to 11, with an average of 8 alleles per locus. Cluster analysis was performed by the UPGMA algorithm and Dice similarity coefficient through NTSYS-pc ver. 2.02 software. The obtained dendrogram classified the studied genotypes into seven categories. Heterozygosity and Shannon Index were estimated using POPGEN 1.32 software. The genetic diversity for the two populations (Iranian and foreign) were calculated using Gene Alex ver. 6.3 software. These findings can be helpful for conservation and selection of these genetic resources and future breeding programs.
Volume 16, Issue 7 (Supplementary Issue - 2014)
Abstract
To determine the phenolic content and antioxidant activity in some native Iranian apple cultivars, some five cultivars namely: 'Bekran', 'Golab-e Kermanshah', 'Golab-e Kohanz' 'Golab-e Sheikhi' and 'Atlasi' were selected and compared with the standard cultivar 'Gala'. The profiles related to four phenolic compounds (chlorogenic acid, quercetin-3-galactoside, catechin, and phloridzin) were determined through HPLC for flesh and flesh+peel of the studied cultivars. Total Phenolic Content (TPC) through Folin-ciocalteu, and antioxidant activity applying DPPH radical (IC50) were also evaluated for flesh vs. flesh+peel for each cultivar. The results of HPLC analysis revealed that catechin constituted the main phenolic compound of flesh and as well the flesh+peel in all the studied cultivars. The highest catechin concentrations in flesh+peel and in flesh were detected in 'Golab-e Kermanshah' (4,064.37 ug g-1 FW) and 'Bekran' (2,315.92 ug g-1 FW), recpectively. The second high concentration phenolic compound was quercetin-3 galactoside, with 'Atlasi' containing the highest content (833.96 ug g-1 FW). A high level of chlorogenic acid was detected in 'Golab-e Sheikhi' (276.106 ug. g-1 FW). The highest level of Total Phenolic Index (TPI) was observed in 'Golab-e Kermanshah' (4392.81ug g-1 FW). The highest TPCs were detected in 'Golab-e Kermanshah' and 'Atlasi'. Phenolic compounds were found as less abundant in the flesh than in the flesh+peel. The scavenging activity of DPPH radical (IC50) revealed a higher antioxidant effect in flesh+peel than in (only) flesh. It can be concluded that in comparison with 'Gala', native Iranian cultivars contained higher concentrations of phenolic compounds, making them appropriate for use in breeding and being reintroduced into the production cycle. Also, it was revealed that whole fruit (flesh+peel) provides phytochemicals in levels far greater than the amounts provided by the fruit’s (only) flesh.
Volume 17, Issue 66 (8-2024)
Abstract
In this article, we criticized Aidan Chambers' theory of the implied reader in children's and young adult literature. Chambers proposes techniques for identifying the implied reader in such literature. While the theory offers useful concepts, it contains flaws and gaps, which we explain under several headings: generalizations and ambiguity in definitions, overlap of categories, inconsistency in examples, and weak theoretical foundations. The proper application of this theory in practice requires revisions, supplements, and corrections, which we have addressed in this study. We further provide suggestions for improving the theory. Given that Chambers' theory aims to uncover the implied reader, we also explored techniques that enable us to identify this reader. In the fields of linguistic analysis of the novel and narratology, we found effective methods and concepts, and we designed an approach based on text structure analysis and narrative discourse, which helps infer the implied reader. This method includes the concepts of sème, focalization, voice, and distance, offering a more precise understanding of the implied reader.
1. Introduction
Considering a specific audience in children's and young adult literature is a necessity for writers in this field, far beyond what is required for adult literature authors. Thus, reader-response criticism is especially important in the realm of children's and young adult literature. Various theories have been proposed with this approach, emphasizing the reader's active engagement with the text and highlighting the reader's role in shaping meaning. In other words, the reader collaborates with the author in creating meaning. One reader-response theory is Aidan Chambers’ theory of the "implied reader," which introduces a reader within children's literature who is present in the text and plays a role in its construction. Chambers also lists techniques for illustrating this reader, including style, point of view, advocacy, and narrative gaps. This theory helps critics understand for whom the story is written.
2. Discussion
While Chambers' theory offers useful concepts, it has some flaws and gaps, which we have explained under several headings: vagueness in definitions, category overlap, inconsistency in examples, and weak theoretical foundations. In light of these criticisms, we attempted to introduce alternative methods to address the shortcomings of the theory. Upon closer inspection, among Chambers' four elements (style, point of view, advocacy, and narrative gaps), only style, point of view, and narrative gaps are tools for illustrating the implied reader, while advocacy pertains more to the relationship between the author and the implied reader rather than being a tool for deducing it.
Given that Chambers himself uses the term "style" in his theory, we initially turned to stylistics. After reflecting on and studying concepts related to stylistics and drawing from other fields such as linguistics and narratology, we found that employing stylistics to identify the implied reader is fraught with ambiguities, and there are much better tools for this purpose. Particularly, in stylistics, the interpretation of any subject depends on its frequency and recurrence. Thus, many significant points in identifying the implied reader would be overlooked simply because they are not frequent. Identifying the implied reader is, in fact, an effort to understand the rhetorical aspect of the text, meaning that by analyzing the surface structure of the text and recognizing the transformations in relation to its deep structure, we aim to understand the characteristics of the reader for whom this text/narrative was created. Therefore, we had to turn to techniques that allow us this rhetorical understanding. In linguistics, many of the topics Chambers aims to analyze under the term "style" are already discussed, such as the author's use of imagery, conscious and unconscious references, hypotheses about the reader's perception, and attitudes toward beliefs, customs, and characters in the narrative. Since the novel is a linguistic-narrative structure, we utilized the linguistics of the novel and narratology to better explain Chambers’ concepts. Roger Fowler's linguistics and the novel was one of the sources we relied on in this endeavor. Fowler introduces a method through which we can analyze the novel as a large narrative structure using linguistic tools. In our proposed analysis method, instead of the stylistics-related techniques like point of view and narrative gaps, which were not very precise, we used the techniques of the linguistics of the novel and narratology to derive a more accurate and well-founded understanding of the implied reader based on textual evidence.
In analyzing the element of the text, we used the concept of "semantic units," through which we can clarify the relationship between the narrator, characters, and implied reader within the novel, and thus infer the author’s perspective toward the implied reader. In the discussion of discourse, we also utilized narratology, employing techniques like focalization, voice, and distance to identify the implied reader. In analyzng the novel, focalization helps us understand how different viewpoints can influence our interpretation and understanding of events and characters. This concept clearly shows that not only “who says” but also “from whose perspective it is said” is equally important in shaping meaning. Through focalization, we can illustrate the implied reader with whom the text intends to communicate.
We also discussed the concept of voice. This concept relates to the analysis of how the speech and thought of characters are represented, showing how the author can reflect different viewpoints and ideologies in the story through various voices. The voices of the narrator and characters play a significant role in directly and indirectly expressing the author's attitude toward the implied reader.
Distance is another discourse-related technique that refers to the relationship between the narrator and the events of the story. This distance can be temporal, spatial, emotional, or epistemic, determining the degree of closeness or detachment of the narrator from the story. In novel analysis, the concept of distance helps us understand how the narrator might create a specific effect on the reader through this distance or closeness, and infer what kind of reader is being targeted.
3. Conclusion
While Aidan Chambers' theory of the implied reader provides valuable insights for researchers and writers of children's and young adult literature, it is not without its shortcomings. In this article, we critically examined Chambers' approach, highlighting its theoretical ambiguities and issues. One of the weaknesses of Chambers’ theory is its vagueness and generality. Chambers presents four techniques for identifying the implied reader, but the explanations for each are unclear, failing to provide precise tools or categories for analysis. Additionally, there is overlap between the concepts of Chambers’ techniques. For instance, style and narrative gaps cover similar aspects, such as the author's conscious and unconscious references. This overlap creates ambiguity, making it difficult for analysts to differentiate between the techniques. Other weaknesses of this theory include inconsistencies in the examples used and weak theoretical foundations. For example, Chambers proposes assumptions about the difficulty of topics and language for children without providing a clear definition or solid theoretical basis. In the next step, we sought to address these flaws by drawing on the linguistics of the novel and narratology to offer a solution for identifying the implied reader. Initially, we used Fowler’s theory regarding the analysis of text structure. Based on this, we found a way to identify the implied reader through analyzing the three elements of text, discourse, and content in the novel. By relying on complementary theories in narratology and linguistics, we planned a more substantial and precise analysis. Thus, in our proposed analysis method, instead of using the imprecise stylistics-related techniques like point of view and narrative gaps, we employed the techniques of novel linguistics and narratology and designed a method based on the analysis of the text structure and narrative discourse, allowing us to identify the implied reader. This method includes the concepts of semantic units, focalization, voice, and distance, which provide a more accurate understanding of the implied reader.
1. Introduction
Considering a specific audience in children's and young adult literature is a necessity for writers in this field, far beyond what is required for adult literature authors. Thus, reader-response criticism is especially important in the realm of children's and young adult literature. Various theories have been proposed with this approach, emphasizing the reader's active engagement with the text and highlighting the reader's role in shaping meaning. In other words, the reader collaborates with the author in creating meaning. One reader-response theory is Aidan Chambers’ theory of the "implied reader," which introduces a reader within children's literature who is present in the text and plays a role in its construction. Chambers also lists techniques for illustrating this reader, including style, point of view, advocacy, and narrative gaps. This theory helps critics understand for whom the story is written.
2. Discussion
While Chambers' theory offers useful concepts, it has some flaws and gaps, which we have explained under several headings: vagueness in definitions, category overlap, inconsistency in examples, and weak theoretical foundations. In light of these criticisms, we attempted to introduce alternative methods to address the shortcomings of the theory. Upon closer inspection, among Chambers' four elements (style, point of view, advocacy, and narrative gaps), only style, point of view, and narrative gaps are tools for illustrating the implied reader, while advocacy pertains more to the relationship between the author and the implied reader rather than being a tool for deducing it.
Given that Chambers himself uses the term "style" in his theory, we initially turned to stylistics. After reflecting on and studying concepts related to stylistics and drawing from other fields such as linguistics and narratology, we found that employing stylistics to identify the implied reader is fraught with ambiguities, and there are much better tools for this purpose. Particularly, in stylistics, the interpretation of any subject depends on its frequency and recurrence. Thus, many significant points in identifying the implied reader would be overlooked simply because they are not frequent. Identifying the implied reader is, in fact, an effort to understand the rhetorical aspect of the text, meaning that by analyzing the surface structure of the text and recognizing the transformations in relation to its deep structure, we aim to understand the characteristics of the reader for whom this text/narrative was created. Therefore, we had to turn to techniques that allow us this rhetorical understanding. In linguistics, many of the topics Chambers aims to analyze under the term "style" are already discussed, such as the author's use of imagery, conscious and unconscious references, hypotheses about the reader's perception, and attitudes toward beliefs, customs, and characters in the narrative. Since the novel is a linguistic-narrative structure, we utilized the linguistics of the novel and narratology to better explain Chambers’ concepts. Roger Fowler's linguistics and the novel was one of the sources we relied on in this endeavor. Fowler introduces a method through which we can analyze the novel as a large narrative structure using linguistic tools. In our proposed analysis method, instead of the stylistics-related techniques like point of view and narrative gaps, which were not very precise, we used the techniques of the linguistics of the novel and narratology to derive a more accurate and well-founded understanding of the implied reader based on textual evidence.
In analyzing the element of the text, we used the concept of "semantic units," through which we can clarify the relationship between the narrator, characters, and implied reader within the novel, and thus infer the author’s perspective toward the implied reader. In the discussion of discourse, we also utilized narratology, employing techniques like focalization, voice, and distance to identify the implied reader. In analyzng the novel, focalization helps us understand how different viewpoints can influence our interpretation and understanding of events and characters. This concept clearly shows that not only “who says” but also “from whose perspective it is said” is equally important in shaping meaning. Through focalization, we can illustrate the implied reader with whom the text intends to communicate.
We also discussed the concept of voice. This concept relates to the analysis of how the speech and thought of characters are represented, showing how the author can reflect different viewpoints and ideologies in the story through various voices. The voices of the narrator and characters play a significant role in directly and indirectly expressing the author's attitude toward the implied reader.
Distance is another discourse-related technique that refers to the relationship between the narrator and the events of the story. This distance can be temporal, spatial, emotional, or epistemic, determining the degree of closeness or detachment of the narrator from the story. In novel analysis, the concept of distance helps us understand how the narrator might create a specific effect on the reader through this distance or closeness, and infer what kind of reader is being targeted.
3. Conclusion
While Aidan Chambers' theory of the implied reader provides valuable insights for researchers and writers of children's and young adult literature, it is not without its shortcomings. In this article, we critically examined Chambers' approach, highlighting its theoretical ambiguities and issues. One of the weaknesses of Chambers’ theory is its vagueness and generality. Chambers presents four techniques for identifying the implied reader, but the explanations for each are unclear, failing to provide precise tools or categories for analysis. Additionally, there is overlap between the concepts of Chambers’ techniques. For instance, style and narrative gaps cover similar aspects, such as the author's conscious and unconscious references. This overlap creates ambiguity, making it difficult for analysts to differentiate between the techniques. Other weaknesses of this theory include inconsistencies in the examples used and weak theoretical foundations. For example, Chambers proposes assumptions about the difficulty of topics and language for children without providing a clear definition or solid theoretical basis. In the next step, we sought to address these flaws by drawing on the linguistics of the novel and narratology to offer a solution for identifying the implied reader. Initially, we used Fowler’s theory regarding the analysis of text structure. Based on this, we found a way to identify the implied reader through analyzing the three elements of text, discourse, and content in the novel. By relying on complementary theories in narratology and linguistics, we planned a more substantial and precise analysis. Thus, in our proposed analysis method, instead of using the imprecise stylistics-related techniques like point of view and narrative gaps, we employed the techniques of novel linguistics and narratology and designed a method based on the analysis of the text structure and narrative discourse, allowing us to identify the implied reader. This method includes the concepts of semantic units, focalization, voice, and distance, which provide a more accurate understanding of the implied reader.
Volume 23, Issue 1 (4-2019)
Abstract
Evaluating entrepreneurial opportunities exemplifies the decision-making under conditions of uncertainty. These evaluations mainly have been done in a complex and dynamic environment under true uncertainty. In contrast to risk and ambiguity, in true uncertainty not only all potential outcomes and their assigned probabilities are unknown, but also it is not possible easily to estimate the probabilities and acquire knowledge about the results. In these situations, entrepreneurs evaluate opportunities based on minimal and inaccurate information, which is described by fuzzy variables, i.e. linguistic variables that do not have any clear boundaries. Hence, adopting a fuzzy approach, the purpose of this paper is to propose a model for evaluating entrepreneurial opportunities under conditions of uncertainty. This study is the first using fuzzy screening to formulate opportunity evaluation as a Multi-Expert Multi-Criteria Decision-Making (ME-MCDM) problem and it is innovative in this research area. In doing so, first, through a systematic literature review and focus group the authors identified entrepreneurs’ current solutions for evaluating opportunities under true uncertainty. Then, a ME-MCDM model has been suggested to evaluate opportunities and select between them. The model is based on fuzzy screening method and evaluates 12 opportunities by 15 experts in a medium entrepreneurial firm. R software has been used to perform calculations. With regard to experts’ aggregate evaluations, findings show that O6 and O11 have higher rating (better evaluation) among opportunities and considered as appropriate candidates for pursuing.
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