Financial Derivative Instruments, which are created by financial experts, play an important role in the world of high finance. To deal with the risk, mainly price risk, these Instruments have appeared and begun to change and promote day in, day out. Their importance may appear when it happens to them to be published more than base stock; great sum of money would be transferred by and ends by paying the difference in price, not caring for contents of contract. This research paper tends to have a juridical analyse over these Instruments. Explaining these Instruments, first their legal nature would be identified and then, juridical judgment would be inferred. Most of the Instruments which are created to satisfy the requirements of economic agents can be revised by law. May be, these Instruments are misused, but this is incidental, as it may happen about other legitimate Instruments like principle of commerce.

There is for a short time that , by virtue of the article 1(11) of IRI Securities market Act 1384 , financial Derivatives market in which future contract and option contract are offered, has started to establish on a limited level. The threshold revenue in such contracts may take the form of goods or securities. From viewpoints of Iranian legal system and Islamic jurisprudence, such contracts have proven to be valid irrespective of their subject (the underlying asset) however the validity of those Derivative contracts the underlying asset of which shall be the index has continued to be doubtful.While rejecting the legal opinions raised by now concerning non-validity of financial Derivatives made on the index, this article seeks to explain its nullity on a different approach. The outputs of this research shall, inter alia, be: the nullity of index contracts for impossibility of its ownership, its valueless and the lack of the very idea of ‘bargain’ in such contracts. As well as, the article contains a way to validate the contracts concluded upon index.

Objective: Usually doing transactions in the Derivative market of a specific mechanism, which requires a sufficient level of knowledge of investors in this field. The same complexities in Derivative financial Instruments can be effective in stimulating the mental anchor drives of investors. Derivative financial Instruments should be considered as a complex issue in the development of financial functions in investment decisions. Therefore, in order to reduce such restrictions in the use of financial Derivative Instruments, many accounting and financial standards drafting boards such as the Financial Accounting Standards Board "FASB" and the Australian Accounting Standards Board "AASB" respectively FASB 133 statements; They compiled FASB 137 and AASb 1033 with the aim of reducing the complications of using these tools. The purpose of this study is evaluation of investors' mental anchor drivers based on the limitation caused by Derivative financial Instruments.Method: In terms of results, this research is considered a development because by relying on qualitative evaluation methods, it seeks to create a theoretical framework to determine the causes of the mental anchor drivers of investors and the sub-factors of restrictions on the use of Derivative financial Instruments. In fact, due to the lack of theoretical coherence regarding concepts and theories related to this field, this research seeks to expand theories and theoretical concepts to create more coherence for future studies. In other words, this research seeks to evaluate the mental anchor drivers of investors in the form of a model based on related researches in this field by establishing the criteria for the limitations of using Derivative financial Instruments. In terms of the purpose of this research, it is applied and in terms of its nature, it is descriptive/survey. In terms of the type of data, this research is considered a mixed method. In this research, firstly, to examine the related concepts of the research variables, meta-composite analysis method is used to analyze textual data with an inductive approach. Then, in the quantitative part, intuitive fuzzy analysis is used to answer the research questions. In this study, in the qualitative part, based on met synthesis processes, an effort was made to first identify the researches related to the two concepts of investors' mental anchor and Derivative financial Instruments, and then determine the components and themes of the research based on the critical appraisal scale. Also, in the continuation of the qualitative part, Delphi process was used to determine the limit of theoretical consensus. In the quantitative part, was used with the aim of determining the most effective drivers of the mental anchor of investors, due to the limitation caused by Derivative financial Instruments in the Tehran Stock Exchange (TSE), Intuitive Fuzzy Sets (IFSs). In this study, 13 of the experts in the (TSE) and at the university level participated in the qualitative part, and 25 of the TSE experts; the financial reporting experts and the issuer supervision department of the Tehran Stock Exchange (TSE) filled out the matrix questionnaires in the quantitative section.Result: The results in the qualitative part indicate the existence of 5 themes of limitations caused by Derivative financial Instruments and 3 driving components of investors' mental anchor. The results in the quantitative part also showed based on the process of fuzzy Vikor process, the most important parameter of the research themes (limitations of using Derivative financial Instruments) is the lack of comparability. It was also found that cognitive drivers are the most effective measure of mental anchor in investors' decisions regarding restrictions on the use of Derivative financial Instruments.Conclusion: The obtained result is an indication of this fact because investors are probably not aware of their perceptual errors in decision-making, they always use the basis of limited rationality to make decisions despite stress and uncertainty situations in decision-making and considering that the criterion of non-comparability as one of the limitations of Derivative financial Instruments is almost dominant in the Iranian market, this issue makes cognitive drivers play a role in the formation of mental anchors in the decision-making of investors. In fact, comparability as one of the indicators of information quality in the use of these tools can bring benefits such as reducing the cost of information processing, and it is through this mechanism that the level of fair valuations on the assets of companies can increase the integrity in the use of tools. Financial Derivatives help. So that by increasing the ability to compare information, the possibility of comparing the similarities and differences between the value of companies is increased and on the other hand, the effort of analysts to understand and analyze financial statements and to better understand the relationship between economic events and company performance is reduced, both of which are an effective factor on The efficiency of the market and the optimal allocation of resources is in the form of expanding the collection of information available to investors and reducing the cost of information, and it provides opportunities to invest in Derivative financial Instruments.

The 2008 Great Financial Crisis increased the fluctuations in the stock market in the US and other countries that were linked together through various channels. In this regard, Derivative Instruments, as one of the main elements of the world's financial markets, had an essential role in reducing the stock market fluctuations and contagion of the crisis. The primary purpose of this study is to examine the negative effect of the Derivative Instruments on the contagion of stock markets in developing countries, including Brazil, India, China, and Russia, using monthly stock and futures indices over the 2007: 01 to 2018: 08. By considering the United States of America as the source of the crisis, the hypothesis was tested with the Copula function and Kendall's tau (rank correlation coefficient). The results have confirmed the hypothesis. According to the findings, we suggest that the economy moving towards openness should develop the Derivative Instruments to minimize the fluctuations as well as reduce the devastating effects of crisis contagion. Also, by upgrading the information of the investors and speculators, it can decrease the depth and intensity of the fluctuations that originated from international crises.

Objective: One of the financial Instruments that plays an important role in investors' decision-making is the Derivative financial instrument, which in Iran's capital market has caused the market balance to be disturbed in terms of control and risk due to the existence of integrated usage restrictions for them. In fact, these financial Instruments can be used both for commercial purposes and for protection against unpredictable risks in investments. But the existence of restrictions on the use of Derivative financial Instruments has caused huge losses, which cannot be hidden as a result of the financial scandals of large companies. Therefore, in order to reduce such restrictions in the use of Derivative financial Instruments, many accounting and financial standards drafting boards such as the American Financial Accounting Standards Board "" and the Australian Accounting Standards Board "" in accordance with  statements; they compiled  and  with the aim of reducing the complications of using these Instruments. The purpose of this research is investigating the limitations of using Derivative financial Instruments in the Iranian capital market. Methods: This research is mixed in terms of data collection methodology, because the lack of a theoretical framework of the financial Instruments limitations has led to the use of these Instruments, at least at the level of the Iranian capital market does not have integrity. Therefore, first, through the process of Meta synthesis and Delphi as the basis of analysis in the qualitative part, an attempt was made to determine the dimensions of the limitations of using Derivative financial Instruments and then its reliability was examined to determine the theoretical consensus. TODIM Fuzzy inference has been used in the quantitative part of the research. Because the purpose of this section was to determine the most important limitation of the integration of the use of Derivative financial Instruments in the Iranian capital market. In this research, in the qualitative part, 15 accounting experts at the university level and in the quantitative part, 25 capital market experts; Experts in financial reporting and the issuer supervision department of the Stock Exchange Organization participated as the statistical population. Results: In this research, based on the fact that the limitations of the integration of the use of Derivative financial Instruments have not been determined in the form of a coherent theoretical framework in the past researches, therefore, in this research, an attempt was made to determine the desired dimensions. The results of the qualitative research through content screening of 11 studies indicate the selection of 7 dimensions of restrictions on the use of Derivative financial Instruments, which were confirmed in two rounds of Delphi analysis, the theoretical limit of these dimensions. The results in the quantitative part of the research based on the TODIM Fuzzy Inference matrix and determining the final weight of each research criterion indicate the selection of Lack of Financial Statement Comparability (A2) as the most important constraint on the integrity of the use of Derivative financial Instruments in the Iranian capital market. Conclusion: The result reflects the fact that comparability as one of the indicators of information quality in the use of these tools can have benefits such as reducing the cost of information processing and it is through this mechanism that the level of fair valuations on corporate assets can help increase the integrity of the use of Derivative financial Instruments. In fact, comparability as one of the indicators of information quality in the use of these tools can bring benefits such as reducing the cost of information processing, and it is through this mechanism that the level of fair valuations on the assets of companies can increase the integrity in the use of tools. Financial Derivatives help. So that by increasing the ability to compare information, the possibility of comparing the similarities and differences between the value of companies is increased and on the other hand, the effort of analysts to understand and analyze financial statements and to better understand the relationship between economic events and company performance is reduced, both of which are an effective factor on The efficiency of the market and the optimal allocation of resources is in the form of expanding the collection of information available to investors and reducing the cost of information, and it provides opportunities to invest in Derivative financial Instruments. While the lack of this capacity in Iran's capital market, due to various reasons such as lack of information transparency or agency cost, has reduced the integrity of the use of this tool at the level of Iran's capital market.

The aim of the present study was the histological evaluation of Enamel Matrix Derivative (EMD) effectiveness for regeneration of periodontal defects. EMD activates cementum synthesis, PDL and bone during the maturation stage of follicole. In this research, EMD was used in surgical defects of premolar teeth in four adult sheep. Muccoperiosteal flap was reflected in buccal site of teeth. The buccal bone plate was removed from mesial to distal in 4 mm depth. After eliminating the cementum by bur and its etching, EMD was applied on exposed dentine and flap was sutured. In opposite sites of those teeth (control sites) the same process was performed without etching. After 100 days, sheep were sacrificed and histological study through light microscopic was performed on black sections of operation sites. The results showed that in test sites, regeneration of cementum and bone was 62/5% and 42/5-50% respectively. But in control sites regeneration of cementum and bone was 37.5% and 32/5-42/5% respectively. Also the migration of junctional epithelium in control sites was 8-10% more than test sites. The important point is that in test sites, cementum was completely attached to undermining dentine. But, in control sites, the gap between cementum and dentine was visible. As a result, this study suggests that EMD promotes periodontal regeneration, and EMD application is a successful achievement in regenerative periodontal therapy.

The future contract is one of the financial Derivative Instruments whose value is determined during the validity period of the contract according to the value of the underlying asset. Futures are considered temporary contracts. In recent years, with the development and prosperity of the cryptocurrency market, a new type of futures contract has become common in the world's major exchanges, which is perpetual and has no expiration date. Traders in the perpetual futures market can keep their Long or short position open for as long as they desire by depositing the required margin and adhering to the funding system. The transformation of the futures contract's structure from temporary to perpetual, and from stock markets to exchanges, has revealed the contract's new legal and financial face. The structure of this contract has been reviewed in this article while outlining the concept and differences between perpetual futures and other futures contracts. The validity of this contract is then explored using legal and jurisprudential standards, and it is concluded that the perpetual future contract is invalid for a variety of reasons, including uncertainty, usury and formality.

Recently financial Instruments designed and produced to oil market. The main objective of designing these Instruments is to improve portfolio risk management and also increasing efficiency of capital markets for making more efficient the Stock Exchange Which the financial Instruments called Derivatives. It is require to issue different securities with diverse risk and return. Issuing new securities it must be considered that dealing such securities should not be in conflict with Islamic regulations. In this article, content and mechanism of dealing Options, Futures contracts discussed first and answering to some criticisms raised in respect of this kind of transaction being such transactions as Ghrry Sale, being such transactions as a kali be kali (as named in Islamic Law) and being such transactions non-recognition of the sale right the Sale may be noted as this article s result.

This paper addresses the scientific realism debate by giving thought to the epistemic status of scientific Instruments. The paper claims that a perspectivist yet realist view is capable of explaining the role of Instruments in science. Thus, instrumental perspectivism is defined and supported against the following three criticisms. 1- Perspectivism leads to relativism. 2- Perspectivists’ view that Instruments represent reality partially is trivial. 3- The perspectivist claim that Instruments are not transparent is either trivial or unacceptable. In response, I defend a realist version of perspectivism on the basis of the concept of “robustness”. I also argue that perspectivism has interesting implications for the plurality of scientific representations and for teaching science to the public. Furthermore, I explain that the (post)phenomenological account of “mediation” sheds light on the assertion that Instruments are not transparent.