Robust Resource Allocation for OFDM-based Cognitive Radio in the Presence of Primary User Emulation Attack

Cognitive radio (CR) is a promising solution to improve the spectrum efficiency in which some unlicensed users are allowed to exploit frequency bands which are not used by licensed network. However, CR technology imposes some threats to the network. One of these threats is primary user emulation attack where some malicious users try to send fake signals similar to the primary user (PU) and prevent secondary users from accessing vacant bands. Moreover, the presence of a primary user emulation attacker (PUEA) leads to additional interference to the CR and consequently, the efficiency of conventional power loading algorithms will be degraded. In this paper, we propose a power allocation scheme in an orthogonal frequency-division multiplexing (OFDM) based CR in the presence of PUEA. Power allocation is performed with the aim of maximizing the downlink transmission capacity achieved by the cognitive user, while keeping the interference level at the PU below a predefined threshold. Simulation results confirm the efficiency of our proposed power loading scheme, compared to classical loading algorithms that do not consider the activity of malicious users in the radio environment

Improvement of Fuzzy Image Contrast Enhancement Using Simulated Ergodic Fuzzy Markov Chains

This paper presents a novel fuzzy enhancement technique using simulated ergodic fuzzy Markov chains for low contrast brain magnetic resonance imaging (MRI). The fuzzy image contrast enhancement is proposed by weighted fuzzy expected value. The membership values are then modified to enhance the image using ergodic fuzzy Markov chains. The qualitative performance of the proposed method is compared to another method in which ergodic fuzzy Markov chains are not considered. The proposed method produces better quality image

The variations of physiological and antioxidant properties in Schefflera arboricola cuttings over the rooting period

Schefflera arboricola (Hayata) Merr. is propagated by leafy stem cuttings. In order to study the biochemical variations and vegetative traits of S. arboricola cuttings over the rooting period, an experiment was carried out on the basis of a randomized complete block design with 13 treatments and three replications. The experimental treatments were composed of indole-3-butyric acid (IBA), naphthaleneacetic acid (NAA), abscisic acid (ABA), salicylic acid (SA) and their combinations at different rates. It was found that hormone application had a favorable impact on rooting and increased rooting percentage in most treatments when compared to control. The application of different hormones influenced morphological traits to varying degrees. According to the findings, the highest rooting percentage was obtained from cuttings treated with 1000 mg L-1 NAA, the highest number of roots was obtained from those treated with 1000 mg L-1 NAA + 200 mL L-1 SA, and the longest roots from those treated with 1000 mg L-1 NAA or 100 µM ABA. Significant differences were observed between two studied ABA rates in chlorophyll contents and peroxidase content. The highest catalase activity was observed in cuttings treated with 1000 mg L-1 IBA + 50 µM ABA + 200 mL L-1 SA

نقش حرارت در سلامت از دیدگاه طب سنتی و پزشکی نوین

In modern science, heat is a quality that enhances the movement of molecules. Maintenance of instinctive temperature in a normal range is vital for healthy organs' function and survival. In the Traditional Persian Medicine, the heat comprised to instinctive that is related to animal spirit and hands the animal life; and stout heat that is related to natural spirit. Instinctive which derived from main spiritual heat has no burning, decay and infection. In traditional medicine, the physician determines the body hotness and coldness of the patient with palpation. However further than palpation, the physician should evaluate the function of main body organs (heart, brain and liver) to estimate instinctive heat. The physician should be moderate in mezaj (temperament) or knows the normal moderate human's mezaj. The maintenance of instinctive heat and humidity plays vital role in healthy life style and longevity. The weather, food and drink, sleep and wake, motion and stillness, retention and evacuation and at last mood are the six main basics for maintaining instinctive temperature. Despite the differences between the definitions and terminology of both traditional and modern perspectives on the heat, the importance of body temperature in metabolism and health is mentioned in both schools. This study is about to provide a context for further attention of the researchers to basic concepts of traditional medicine.حرارت در علم نوین کیفیتی است که باعث افزایش حرکت مولکول‌ها می‏شود. بقای انسان وابسته به نگهداری حرارت درونی تا حدی است که افعال بدنی در آن به‌درستی انجام گیرد. از دیدگاه طب سنتی، حرارت دو نوع است: غریزی و اُسطُقُسی. حرارت غریزی، حرارت ذاتی است که گرمی آن سوزندگی، تعفین و فساد ندارد. در طب سنتی، طبیب برای تعیین گرمی و سردی مَلمَس بیمار از دست خود استفاده می‌کند، اما ملمس بیمار برای تعیین حرارت غریزی بیمار کافی نیست. علاوه بر ملمس، افعال اندام‌های رئیسه یعنی قلب، مغز و کبد نیز باید بررسی شوند. حفظ حرارت غریزی و رطوبت، نقش حیاتی در تندرستی و طول عمر دارد. هوا، غذا و نوشیدنی، خواب و بیداری، حرکت و سکون، احتباس و استفراغ و درنهایت، اعراض نفسانی یا حالات روحی شش اصل اساسی حفظ حرارت غریزی هستند. تغییر کیفیات مانند حرارت منجر به ایجاد سوء‏مزاج در اندام‌ها و بیماری می‏شود. باوجود تفاوت میان تعاریف و اصطلاحات دو دیدگاه سنتی و نوین درباره حرارت، در هر دو مکتب به اهمیت حفظ حرارت درونی بدن و نقش آن در سوخت‌وساز و سلامت اذعان شده است. این تحقیق بر آن است زمینه‌ای برای توجه بیشتر پژوهشگران به مفاهیم پایه‌ای طب سنتی فراهم آورد.   &nbsp

Evaluation of analgesic effects of intrathecal eugenol in male rats

زمینه و هدف: اوژنول مهمترین ماده تشکیل دهنده عصاره گیاه میخک (Eugenia caryophylata) است که به طور گسترده در دندانپزشکی جهت تسکین درد و التهاب موضعی استفاده می‌شود. از آنجایی که مطالعه‌ای در زمینه تزریق داخل نخاعی اوژنول از نظر شروع و طول مدت بیدردی انجام نشده است، لذا این مطالعه با هدف ارزیابی اثرات ضددردی تجویز داخل نخاعی اوژنول از نظر شروع و طول مدت اثر آن در موش های صحرایی نر انجام شده است. روش بررسی: در این مطالعه تجربی 51 سر موش صحرایی نر نژاد ویستار در سه گروه اوژنول و سه گروه نرمال سالین قرار گرفتند. 5 روز بعد از کاتتر گذاری در نخاع از ناحیه کمر (تحت بی‌هوشی) اثرات تجویز داخل نخاعی حجم‌های مختلف اوژنول و نرمال سالین (5، 10 و 15 میکرولیتر به ازای هر حیوان) در زمان‌های قبل از کاتترگذاری، قبل از تجویز و 10، 30، 180، 360، 720 و1440 دقیقه بعد از تجویز، روی درد ناشی از قرار دادن دم در آب ºc51 بررسی و مقایسه شد. داده‌ها با استفاده از آزمون آماری ANOVA و آزمون LSD تجزیه و تحلیل شد. یافته‌ها: نتایج این تحقیق نشان داد که عمق و طول مدت بیدردی اوژنول وابسته به دوز بوده و مقادیر بالاتر باعث فلج و بی‌حرکتی طولانی مدت گردید (05/0

The role of professors and students in developing and revising the universities curriculum in Afghanistan

The main aim of this research is the professors and students involvement in the main decision-making of developing and revising the Afghanistan university curriculum? The researcher has used the latest studies related to this issue in other countries for the field research, a mixed-method (quantitative and qualitative), were used. The results of previous studies in other countries indicate that the role of professors and students in Developing or revising the university curriculum are highly significant, the present study indicates that despite the efforts of the Afghan Ministry of Higher Education in revising the curriculum, there are still significant issues. In achieving an ideal curriculum, otherwise, the curriculum would face serious challenges

Assessment the effect of N Acetyl Cysteine on liver function test in patient with elective Coronary Artery Bypass Grafting with cardiopulmonary bypass

Background: Liver ischemic insults are important sources of liver injuries leading to production of reactive oxygen species (ROS) and mediating liver cell injury. Glutathione mediated mechanisms are among the most important defense mechanisms of the liver; N-acetylcysteine (NAC) provides cysteine for glutathione defense mechanisms. Patients undergoing cardiac surgery are at increased risk of liver ischemia. This study was performed to assess the role of NAC in prevention of liver ischemia.Materials and Methods: In a double blind, randomized clinical trial, 90 patients entered the study in two groups (45 in each). Patients in the NAC group received 150 mg/Kg NAC after induction of anesthesia and the other group, the same volume of placebo. Serum levels of aspartate aminotransferase (AST), Alanine aminotransferase (ALT) and bilirubin were checked before and after the surgery. ANOVA was used for data analysis and p value less than 0.05 was considered statistically significant.Results: No difference between the two groups regarding basic variables; however, the postoperative values of AST and ALT were lower in the NAC group with statistically significant difference. Also, postoperative levels of total bilirubin were lower in the NAC group compared with the control group; a statistically significant difference.Conclusion: Patients undergoing CABG are advised to receive prophylactic 150 mg/Kg NAC to improve their postoperative levels of AST, ALT and bilirubin.Keywords: glutathione antioxidant mechanism, N-acetylcysteine; Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), bilirubin, liver ischemia

Investigating the Mediating Role of Distress Tolerance in the Relationship between Early Maladaptive Schemas and Psychiatric Symptoms among Addicts

Background: This study aimed to determine the mediating role of distress tolerance in the relationship between early maladaptive schemas and psychiatric symptoms among addicts. Methods: The statistical population of this study consists of addicts referring to addiction treatment clinics in Zanjan city, Iran. Using the multi-stage cluster sampling method, 150 participants were selected as a sample and completed the questionnaires. Early maladaptive schema questionnaire-short form, symptom checklist-25 (SCL-25), and the distress tolerance scale were completed by participants. Results: The findings of this study indicate a negative and significant relationship between early maladaptive schemas and distress tolerance among addicts. Also, there is a positive and significant relationship between early maladaptive schemas and psychiatric symptoms among addicts. It can be said that there is a significant negative relationship between distress tolerance and psychiatric symptoms in addicts. Conclusions: The final results of this study show that in the relationship between early maladaptive schemas and psychiatric symptoms among addicts in Zanjan city, distress tolerance plays a mediating role and the model has a goodness of fit. Keywords: Distress tolerance, Early maladaptive schemas, Psychiatric symptoms, Addicts

Investigating the Mediating Role of Distress Tolerance in the Relationship between Early Maladaptive Schemas and Psychiatric Symptoms among Addicts

Background: This study aimed to determine the mediating role of distress tolerance in the relationship between early maladaptive schemas and psychiatric symptoms among addicts. Methods: The statistical population of this study consists of addicts referring to addiction treatment clinics in Zanjan city, Iran. Using the multi-stage cluster sampling method, 150 participants were selected as a sample and completed the questionnaires. Early maladaptive schema questionnaire-short form, symptom checklist-25 (SCL-25), and the distress tolerance scale were completed by participants. Results: The findings of this study indicate a negative and significant relationship between early maladaptive schemas and distress tolerance among addicts. Also, there is a positive and significant relationship between early maladaptive schemas and psychiatric symptoms among addicts. It can be said that there is a significant negative relationship between distress tolerance and psychiatric symptoms in addicts. Conclusions: The final results of this study show that in the relationship between early maladaptive schemas and psychiatric symptoms among addicts in Zanjan city, distress tolerance plays a mediating role and the model has a goodness of fit. Keywords: Distress tolerance, Early maladaptive schemas, Psychiatric symptoms, Addicts