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Volume 24, Issue 3 (Autumn 2024)
Abstract
Introduction
In international trade network, countries are classified into different societies. These societies are formed based on commercial relations. Countries that are in the same society have close trade relations, while countries that are in different societies have much weaker trade relations, which shows that classification phenomenon has a meaningful effect on the field of international trade of resources. These societies also significantly promote free trade and improve commercial security and create favorable business conditions. For countries that rely heavily on foreign resources, establishing trade zones or joining a trade zone for their long-term development is of paramount importance. The division of societies in the trade network is based on geographical location or gross domestic product, not regional trade agreements. Some researchers have investigated the evolutionary characteristics of societies and analyzed the sustainability of international trade. In addition, some researchers argue that societies increase their commercial power by stabilizing the flow of resources in international trade, and their international position improves through cooperation with other countries. Several studies have provided a lot of knowledge about the society and the structural features of the international trade network, but few studies have dealt with the formation of trade areas and what promotes the formation of a trade area. The formation of trade communities/regions can be a strategy to reduce restrictions and increase trade interactions and its security through close communication between countries. Therefore, the current study can become more necessary in the situation where the current international business cooperation has become more and more important. Therefore, two main questions arise that need to be answered: 1) How are business areas formed, and 2) What factors influence the formation of business areas? Based on the studies, resource dependence theory and complex network theory can explain these questions well. Resource dependence theory states that if a firm is highly dependent on the target market, then it will be constrained by the actors in that market. Complex network theory is also a useful tool for systematically analyzing interactions between countries, especially when there are many countries involved and strong links between them exists. The purpose in fact was to investigate and recognize the influence of the resource dependence theory and the complex network theory in the formation of international trade areas in line with the integration of global economy.
Methodology
The data were extracted from the 22 countries active in international trade and based on the availability of the data of the official COMTRADE database of the United Nations in the period of 2011-2021. They account for the entire international trade. In order to analyze the data and estimate the models, negative binomial regression was used because when there are countable and discrete data as the response variable, simple linear regression is not a suitable fitting method. So, Poisson regression was applied, which is considered a method in "generalized linear models" where the probability function for the "response variable" is considered to be "Poisson distribution" and suitable for count data.
Findings
The trade partner factor has a positive effect on the formation of international trade communities, that is, when a country cooperates with a large number of trade partners or has a superior position in the international trade network, it is more likely that other countries will form the same pattern. Therefore, when a country considers itself dependent on the resources of other countries, the possibility of forming a similar society will increase. Finally, network position plays a positive role in moderating the relationship between resource dependence and international trade areas.
Discussion and Conclusion
Based on resource dependence and complex network theory, and analyzing the decisive factors affecting the accession process of a country to the same trade zones, the dependence of the country's imports on the external environment is an integral factor in joining a country to the same trade zones. In fact, in choosing partners for the formation of commercial zones, countries attach great importance to the ability to provide resources of commercial partners. On the other hand, position of the network plays a positive role in the formation of a business community. Countries with a higher network position can not only access resources or reach the target market faster, but also have more control over the flow of resources. Therefore, it is more likely that countries will establish closer trade relations with countries that have a higher network position in order to increase their economic power. The more central a country's network position is, the easier it is to choose to join larger trade areas with other countries. Also, according to the resource dependence theory, the more central a country's network position is, the more likely it is to join the same trade areas as other countries. Network and resource considerations both simultaneously play a role in the strategic choice of national trade. In the case of countries that have the same resource abundance, a country can choose to form the same society as countries that have a more central network position. Finally, due to the development of export markets for domestic products, countries are easily affected by the network position. This will enable them to choose other countries that are in a more central network position to form the same society, rather than trying to trade among them. Based on the economic freedom factor and the diversity of the importing country, countries that can strengthen resource trade, can reduce or manage their dependence on other countries. In addition, they can balance the inventory and production of global resources.
In international trade network, countries are classified into different societies. These societies are formed based on commercial relations. Countries that are in the same society have close trade relations, while countries that are in different societies have much weaker trade relations, which shows that classification phenomenon has a meaningful effect on the field of international trade of resources. These societies also significantly promote free trade and improve commercial security and create favorable business conditions. For countries that rely heavily on foreign resources, establishing trade zones or joining a trade zone for their long-term development is of paramount importance. The division of societies in the trade network is based on geographical location or gross domestic product, not regional trade agreements. Some researchers have investigated the evolutionary characteristics of societies and analyzed the sustainability of international trade. In addition, some researchers argue that societies increase their commercial power by stabilizing the flow of resources in international trade, and their international position improves through cooperation with other countries. Several studies have provided a lot of knowledge about the society and the structural features of the international trade network, but few studies have dealt with the formation of trade areas and what promotes the formation of a trade area. The formation of trade communities/regions can be a strategy to reduce restrictions and increase trade interactions and its security through close communication between countries. Therefore, the current study can become more necessary in the situation where the current international business cooperation has become more and more important. Therefore, two main questions arise that need to be answered: 1) How are business areas formed, and 2) What factors influence the formation of business areas? Based on the studies, resource dependence theory and complex network theory can explain these questions well. Resource dependence theory states that if a firm is highly dependent on the target market, then it will be constrained by the actors in that market. Complex network theory is also a useful tool for systematically analyzing interactions between countries, especially when there are many countries involved and strong links between them exists. The purpose in fact was to investigate and recognize the influence of the resource dependence theory and the complex network theory in the formation of international trade areas in line with the integration of global economy.
Methodology
The data were extracted from the 22 countries active in international trade and based on the availability of the data of the official COMTRADE database of the United Nations in the period of 2011-2021. They account for the entire international trade. In order to analyze the data and estimate the models, negative binomial regression was used because when there are countable and discrete data as the response variable, simple linear regression is not a suitable fitting method. So, Poisson regression was applied, which is considered a method in "generalized linear models" where the probability function for the "response variable" is considered to be "Poisson distribution" and suitable for count data.
Findings
The trade partner factor has a positive effect on the formation of international trade communities, that is, when a country cooperates with a large number of trade partners or has a superior position in the international trade network, it is more likely that other countries will form the same pattern. Therefore, when a country considers itself dependent on the resources of other countries, the possibility of forming a similar society will increase. Finally, network position plays a positive role in moderating the relationship between resource dependence and international trade areas.
Discussion and Conclusion
Based on resource dependence and complex network theory, and analyzing the decisive factors affecting the accession process of a country to the same trade zones, the dependence of the country's imports on the external environment is an integral factor in joining a country to the same trade zones. In fact, in choosing partners for the formation of commercial zones, countries attach great importance to the ability to provide resources of commercial partners. On the other hand, position of the network plays a positive role in the formation of a business community. Countries with a higher network position can not only access resources or reach the target market faster, but also have more control over the flow of resources. Therefore, it is more likely that countries will establish closer trade relations with countries that have a higher network position in order to increase their economic power. The more central a country's network position is, the easier it is to choose to join larger trade areas with other countries. Also, according to the resource dependence theory, the more central a country's network position is, the more likely it is to join the same trade areas as other countries. Network and resource considerations both simultaneously play a role in the strategic choice of national trade. In the case of countries that have the same resource abundance, a country can choose to form the same society as countries that have a more central network position. Finally, due to the development of export markets for domestic products, countries are easily affected by the network position. This will enable them to choose other countries that are in a more central network position to form the same society, rather than trying to trade among them. Based on the economic freedom factor and the diversity of the importing country, countries that can strengthen resource trade, can reduce or manage their dependence on other countries. In addition, they can balance the inventory and production of global resources.
Volume 24, Issue 6 (11-2022)
Abstract
Water hardness can negatively affect the efficiency of pesticides. This study aimed to determine the effect of water hardness and adjuvants added to spray solution on the efficiency of insecticides. Three insecticides, namely, malathion, acetamiprid, and spiromesifen, were mixed in well water samples at 1,869, 645, and 265 mg L-1 hardness, standard, and deionized water, and applied against the second instar nymph of Bemisia tabaci using leaf dip method. In another experiment, Zero-7 at 150 ppm and Arkan at 180 ppm as additives were added to water with 1869 and 645 mg L-1 hardness, separately. LC50 values showed that the toxicity of malathion, acetamiprid, and spiromesifen was 40, 157, and 84 times less in hard water (1,869 mg L-1 hardness) than deionized water. The efficacy of malathion, acetamiprid, and spiromesifen was 13, 65, and 39 times less when they were diluted in water with 645 mg L-1 hardness than deionized water. Malathion provided 37.28 and 18.59% greater toxicity when applied in hard water containing Zero-7 and Arkan than water without the adjuvants. The efficacy of acetamiprid was, respectively, 16.93 and 18.68% greater when it was applied in hard water containing Zero-7 and Arkan compared to water without the additives. Zero-7 and Arkan in hard water enhanced the efficacy of spiromesifen by 10.26 and 13.68% compared to water without adjuvants. Generally, the toxicity of the insecticides on B. tabaci was considerably reduced at the highest levels of water hardness. In contrast, adjuvants overcame the antagonistic effects of cations in hard water.
Volume 25, Issue 1 (Winter 2022)
Abstract
Introduction: endurance and resistance exercise and the consumption of hawthorn alone and in combination have an effect on Alzheimer's disease.This study was conducted with the aim of the effect of hawthorn consumption and exercise on the inflammatory indices of Alzheimer's rats by trimethyltin chloride (TMT).
Materials and methods: rats were randomly divided into 9 healthy control and Alzheimer's groups with interventions (control, endurance training, resistance training, combined training, hawthorn, endurance training + hawthorn, resistance training + hawthorn, combined training + hawthorn). Then Alzheimer's disease developed. performed resistance , combined ,endurance exercises every week (12 weeks). Finally, blood was taken from the inferior vena and the inflammatory variables CRP, IL-6 ,TNF-α were measured by ELISA method. The Shapiro-Wilk test was used to check the normal distribution of the data, and the one-way analysis of variance (ANOVA) was used to check the mean difference between the groups (Tukey's test). P <0.05 were considered statistically significant.
Results: results showed that the induction of Alzheimer's disease induced by TMT caused a significant increase in the levels of TNF α, IL 6, CRP in the Alzheimer's control group compared to the healthy control. And 12 weeks of combined training with and without hawthorn had a significant decrease in the level of these variables compared to Alzheimer's control.
Conclusion: As a result, endurance and resistance sports along with the consumption of hawthorn lead to the reduction of some inflammatory factors in Alzheimer's rats.
key words: Alzheimer Disease, Hawthorn
TNF-α , CRP , IL-6 .
Volume 25, Issue 2 (Spring 2022)
Abstract
Introduction: Ferritin is an indicator of iron (Fe) storage in the body and plays the main role of cellular oxidation. It is hypothesized that Fe causes insulin resistance and then by reducing insulin secretion leads to type 2 diabetes. Considering the effects of exercise training in increasing insulin sensitivity, this study was designed the effect of various resistance (DR), endurance (DE), and combined (DER) activities on serum ferritin and Fe levels in diabetic rats. Materials and methods: Type 2 diabetes was induced by intraperitoneal injection of Nicotinamide solution (120 mg/kg) and Streptozotocin (65 mg/kg). One week after the confirmation of diabetes, the training groups underwent DR, DE and DER exercises for 10 weeks. After completing the research protocol, blood sampling was done to measure serum ferritin and Fe levels. Results: Type 2 diabetes caused an adverse increase in blood glucose, insulin levels, increased HOMA-IR, Fe, serum ferritin and decreased HOMA-IS. Looking to improve glycemic indices after 10 weeks of DE, DR and DER training, we saw a decrease in serum Fe and ferritin levels, and DER training had a significant decrease in Fe compared to DR and DE training. Conclusion: This study shows that serum iron and ferritin levels in diabetes are significantly increased and increased ferritin may be one of the reasons for insulin resistance in diabetes. Given the importance of iron and ferritin levels in insulin resistance, combined exercise with moderate intensity and time by reducing these biomarkers can reduce glycemic indices in diabetes.
Volume 25, Issue 3 (Summer 2022)
Abstract
Aim: Applying deep brain stimulation at low-frequency has anticonvulsant effect on kindled seizures. In this study, the effect of low-frequency stimulation (LFS) on kindling-induced changes in the dendritic length of hippocampal CA1 neurons was investigated.
Methods: To administer LFS in the hippocampus, animals first underwent stereotactic surgery and a tripolar electrode were positioned in the CA1 region. Animals received intraperitoneal pentylenetetrazole (PTZ; 34 mg/kg) every other day until they showed three consecutive stage 4 or 5 seizures. LFS was administered to the dorsal hippocampal CA1 area in kindled+LFS group. Hippocampal samples were prepared for stereological assessment one week after termination of LFS application.
Results: PTZ kindling was accompanied with a decrease in dendritic length in CA1 neurons. One week after application of LFS, the length of dendrites was restored to control group values, and there was a significant difference between kindled+LFS and kindled groups. Interestingly, the effect of administering LFS alone in control group, was similar to that of kindled group and a significant decrease was observed in dendritic length.
Conclusion: LFS had a restoring effect on morphological changes in CA1 neurons of kindled animals. This effect may be considered a mechanism for therapeutic action of deep brain stimulation in seizure.
Volume 25, Issue 3 (Summer 2022)
Abstract
Novel antiepileptic drugs (AED) are now available. However, many epileptic patients still find the condition difficult to handle. Drug therapy does not work for about one-third of the cases and not all people who will benefit from surgery. The use of electric current as a treatment option has emerged since the late twentieth century. Inhibition of synapse activity is a way that low-frequency stimulation (LFS) prevents epileptic activity. It will enhance the endocytosis of AMPA-type glutamate receptors and activate calcineurin, thereby leading to long-term depression (LTD). High-frequency stimulation (HFS) also contributes to the control of epilepsy by increasing the membrane permeability of neurons. Nonetheless, the detailed mechanisms responsible for these effects are still unknown. More research is required to fine-tune electrical stimulation parameters and yield better results in epilepsy patient care.
Volume 25, Issue 4 (Fall 2022)
Abstract
Olfactory system may be considered as a target for deep brain stimulation. In experimental researches, it is difficult to insert an electrode in the olfactory epithelium (OE) of laboratory animals, including mice, through nasal cavity. Therefore, it is necessary to find a method for insertion of electrodes in the OE. In the present study we introduce a new method for electrode implantation in mice OE. Male C57BL/6 mice, aged 3-4 months were used. Animals were anesthetized and a pair of bipolar electrodes were inserted into the OE through a hole on the nasal bone. Field potential recordings were made from olfactory bulb and confirmed the electrode positions in OE, so that OE stimulation led to field excitatory post synaptic potentials (fEPSP) in olfactory bulb. In addition, considering the connection between olfactory system and hippocampus, the fEPSPs were also recorded in the hippocampus after a long synaptic delay. On the whole, we introduced a method for OE stimulation in mice as a common laboratory animal. This methos may be suitable in deep brain stimulation experiments in different animal models of neurological diseases.
Volume 26, Issue 1 (Spring 2022)
Abstract
Introduction
The strategic city of Mahshahr port is one of the sensitive and key urban spaces of Khuzestan province and the country, which plays a vital role in the export and import of various oil and non-oil materials and goods due to its brilliant historical background, and in political, commercial, security, economic, social, and environmental aspects has a special importance and status. An examination of the historical trend of the location of Mahshahr port shows that the importance of this strategic space is increasing with an increasing speed. Due to the internal correlation of sustainable urban development indicators to each other, the development of Mahshahr port city should be in all its aspects, so that along with economic development, social and environmental development also should be done, because if there is no coordination between the dimensions of sustainable urban development of Mahshahr port, comprehensive development will not happen, and the potentials of sustainable development of Mahshahr port city will not be used optimally. Another issue of sustainable development of Mahshahr port city is that attention is paid only to the port position of this city for economic development, while Mahshahr city has many capacities in other human and natural sectors, especially tourism (natural and human) for sustainable urban development. It should be considered as medium-term and long-term plans. Therefore, explaining the factors affecting the sustainable development of this key port by relying on futures studies can play a significant role in the all-round development of this city. Thus, the main question of the present study is: What are the key drivers of sustainable development in the port city of Mahshahr with a futuristic approach?
Methodology
The present research is applied in terms of purpose and in terms of nature and method is based on new methods of futurology, analytical, and exploratory science. Questionnaire and Delphi technique and documentary and library studies have been used to collect the required data and information. To apply the Delphi technique and analyze the cross-effects, questionnaires have been prepared in two stages. The first stage includes 50-item open questionnaires, in which the most important factors affecting the sustainable development of Mahshahr port city have been provided to experts in the central issues considering different areas and comprehensive sustainable development, which led to the general extraction of factors affecting sustainable development in the port city of Mahshahr. The second stage includes 30-item questionnaires to determine the main factors affecting the sustainable development of Mahshahr port city through weighting, which were completed by the experts and finally used to analyze the collected data from MicMac software.
Results and discussion
Among the 35 main factors affecting the sustainable development of Mahshahr port city, a total of 8 key variables affect the sustainable development of Mahshahr port city. Thus, these variables have the most and least impacts on the future of sustainable development of Mahshahr port city and include the factors of "domestic tourism development (V4), urban development plans (V19), efficient local management (V21), efficient macro management" (V23), education (V24), communication network (V28), security (V30), and geographical location of Mahshahr port (V33) ".
Conclusion
Sustainable urban development is a multifaceted process that is influenced by various economic, socio-cultural, and environmental factors. Given the interdependence of each of these factors success or failure to achieve sustainable urban development depends on the type of planning and institutional capacity of city officials regarding sustainable urban development. Geographical location and human characteristics of Mahshahr port city has provided the necessary infrastructure for the development of urban sustainability in the city. Due to the high impact of the role of management on other factors, adoption of rational policies regarding sustainable urban development by managers and officials of Mahshahr port city, can determine the directions of success or failure of sustainable development of this port city.
The strategic city of Mahshahr port is one of the sensitive and key urban spaces of Khuzestan province and the country, which plays a vital role in the export and import of various oil and non-oil materials and goods due to its brilliant historical background, and in political, commercial, security, economic, social, and environmental aspects has a special importance and status. An examination of the historical trend of the location of Mahshahr port shows that the importance of this strategic space is increasing with an increasing speed. Due to the internal correlation of sustainable urban development indicators to each other, the development of Mahshahr port city should be in all its aspects, so that along with economic development, social and environmental development also should be done, because if there is no coordination between the dimensions of sustainable urban development of Mahshahr port, comprehensive development will not happen, and the potentials of sustainable development of Mahshahr port city will not be used optimally. Another issue of sustainable development of Mahshahr port city is that attention is paid only to the port position of this city for economic development, while Mahshahr city has many capacities in other human and natural sectors, especially tourism (natural and human) for sustainable urban development. It should be considered as medium-term and long-term plans. Therefore, explaining the factors affecting the sustainable development of this key port by relying on futures studies can play a significant role in the all-round development of this city. Thus, the main question of the present study is: What are the key drivers of sustainable development in the port city of Mahshahr with a futuristic approach?
Methodology
The present research is applied in terms of purpose and in terms of nature and method is based on new methods of futurology, analytical, and exploratory science. Questionnaire and Delphi technique and documentary and library studies have been used to collect the required data and information. To apply the Delphi technique and analyze the cross-effects, questionnaires have been prepared in two stages. The first stage includes 50-item open questionnaires, in which the most important factors affecting the sustainable development of Mahshahr port city have been provided to experts in the central issues considering different areas and comprehensive sustainable development, which led to the general extraction of factors affecting sustainable development in the port city of Mahshahr. The second stage includes 30-item questionnaires to determine the main factors affecting the sustainable development of Mahshahr port city through weighting, which were completed by the experts and finally used to analyze the collected data from MicMac software.
Results and discussion
Among the 35 main factors affecting the sustainable development of Mahshahr port city, a total of 8 key variables affect the sustainable development of Mahshahr port city. Thus, these variables have the most and least impacts on the future of sustainable development of Mahshahr port city and include the factors of "domestic tourism development (V4), urban development plans (V19), efficient local management (V21), efficient macro management" (V23), education (V24), communication network (V28), security (V30), and geographical location of Mahshahr port (V33) ".
Conclusion
Sustainable urban development is a multifaceted process that is influenced by various economic, socio-cultural, and environmental factors. Given the interdependence of each of these factors success or failure to achieve sustainable urban development depends on the type of planning and institutional capacity of city officials regarding sustainable urban development. Geographical location and human characteristics of Mahshahr port city has provided the necessary infrastructure for the development of urban sustainability in the city. Due to the high impact of the role of management on other factors, adoption of rational policies regarding sustainable urban development by managers and officials of Mahshahr port city, can determine the directions of success or failure of sustainable development of this port city.
Volume 26, Issue 1 (Winter 2023)
Abstract
Epilepsy is a neurological disorder characterized by recurrent seizures resulting from abnormal neuronal activity in the brain. The olfactory system is implicated in temporal lobe epilepsy (TLE), and some areas of the olfactory system may serve as sources of seizures. TLE patients often experience olfactory sensations or auras before seizure onset, and olfactory stimulation has been shown to modulate or suppress seizure activity. The connection between the OB and certain brain areas, including the hippocampus, plays a significant role in the spread and propagation of seizure attacks. The document highlights the anatomical and functional relationship between the OB, entorhinal cortex, and hippocampus, suggesting that the olfactory system is involved in the pathogenesis of epilepsy.
Volume 26, Issue 3 (Summer 2023)
Abstract
Alzheimer's is a neurodegenerative disorder characterized by memory impairment and learning difficulties. Alzheimer's disease is recognized as the most common cause of memory loss and dementia in middle-aged and elderly individuals, and it is the fifth leading cause of death among the elderly. Extensive research is being conducted to identify the causes and pathological mechanisms involved in this disease, as a proper understanding of these mechanisms could lead to the discovery of fundamental treatments. In this article, we have looked at some of the pathological mechanisms of this disease, which result from changes in synaptic function and functional connectivity.