Joint Adaptive Modulation-Coding and Cooperative ARQ for Wireless Relay Networks

This paper presents a cross-layer approach to jointly design adaptive modulation and coding (AMC) at the physical layer and cooperative truncated automatic repeat request (ARQ) protocol at the data link layer. We first derive an exact closed form expression for the spectral efficiency of the proposed joint AMC-cooperative ARQ scheme. Aiming at maximizing this system performance measure, we then optimize an AMC scheme which directly satisfies a prescribed packet loss rate constraint at the data-link layer. The results indicate that utilizing cooperative ARQ as a retransmission strategy, noticeably enhances the spectral efficiency compared with the system that employs AMC alone at the physical layer. Moreover, the proposed adaptive rate cooperative ARQ scheme outperforms the fixed rate counterpart when the transmission modes at the source and relay are chosen based on the channel statistics. This in turn quantifies the possible gain achieved by joint design of AMC and ARQ in wireless relay networks.Comment: 5 pages, 4 figures, To appear in the Proceedings of the 2008 IEEE International Symposium on Wireless Communication Systems (ISWCS), Rykevick, Island, Oct 200

Culture and molecular characterization of phages isolated from rainbow trout farms and sewage treatment plants and investigation of their effects on Yersinia ruckeri

In the present study bacteriophages isolated from rainbow trout farms and sewage treatment plants were genetically identified and their effectiveness on Yersinia ruckeri isolates from clinical cases of red mouth disease was investigated. Fish samples suspected to red mouth disease were collected from rainbow trout farms located in west Azerbaijan. Y. ruckeri, the causative agent of red mouth disease was initially identified using biochemical tests. The biotypes of all Y. ruckeri isolates were determined and their identity was confirmed by employing genus specific primers. Antimicrobial resistance of Y. ruckeri isolates were examined using common antibiotics in use in aquaculture. In order to isolating lytic bacteriophages, environmental samples mainly from rainbow trout farms and sewage treatment plants were collected in a period of six months. Isolated bacteriophages were titrated using two-layer agar method and their bactericidal effects were examined. For molecular characterization of bacteriophages, genomic DNA was extracted. Extracted genomic DNA from bacteriophages was digested using MspI endonuclease. The results revealed that 4.48% of examined fish were positive for Y. ruckeri. Bacteriophages isolated from urban sewage treatment plants were effective on Y. ruckeri isolates. Maragheh and Urmia sewage treatment plants had the maximum and minimum phage titers, respectively. The genomic DNA of all isolated phages were smaller than genomic DNA of Lambda phage and all examined phages showed similar genomic DNA digestion patterns. It was concluded that sewage treatment plants could be an important source for phages effective on Y. ruckeri and maybe other aquaculture bacterial pathogens

Correlation of serum adiponectin level with some biochemical and metabolic factors in stable hemodialysis patients

Introduction: Serum adiponectin is a hormone secreted by the adipose tissue and its level usually increases in patients with renal insufficiency. In uremic condition, it not only loses its protective role against atherosclerosis, but also becomes a risk factor. This hormone is a direct predictor of cardiovascular complications in patients with renal failure. Objectives: This study was designed to assess the association between serum adiponectin with various parameters in in a group of non-diabetic hemodialysis patients. Patients and Methods: In this study, 73 hemodialysis non-diabetic patients were selected and fasting blood samples were taken to measure adiponectin and some other biochemical parameters. Waist circumference, abdominal circumference, weight and body mass index (BMI) were measured. Pearson statistical test was used to find the association between adiponectin and mentioned parameters. Results: Adiponectin level was negatively and significantly associated with weight (P<0.001), BMI (P<0.001), waist circumference (P<0.05), abdominal circumference (P<0.01), and triglycerides (P<0.01). Conclusion: According to the results of our study, serum adiponectin level in hemodialysis patients was negatively associated with weight and BMI which indicates the likely effect of the hormone. As a result, finding of exact connections between this cytokines and the risk factors of atherosclerosis and hypercatabolism may help to introduce serum adiponectin as a measurable and important marker for atherosclerosis and may be used as an index for prognosis of mortality in this type of patients. Keywords: Adiponectin, Kidney failure, Hemodialysis Please cite this paper as: Tamadon MR, Heidari M, Dris F, Mardani S. Correlation of serum adiponectin level with some biochemical and metabolic factors in stable hemodialysis patients. J Parathyr Dis 2015;3(1):20-24. Copyright © 2015 The Author(s); Published by Nickan Research Institute. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

The effects of Momordica charantia on liver function and histological structure

Introduction: The application of herbal plants because of their lower side-effects has been increasing in recent years. Objectives: we aimed to study the effects of hydro-alcoholic extract of Momordica charantia (bitter melon) on liver function and tissue structure in mice. Materials and Methods: This study was conducted on 70 male mice which were randomly designated into 7 groups of 10 and were injected with single doses of 0, 100, 500, 1000, 2000 and 4000 mg/kg and multiple daily dose of 500 mg/kg for 7 days, intraperitoneally. Finally, liver tissues were taken out for histological examinations. Serum samples were assayed for liver enzymes activities of alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase. Also the antioxidant activity of blood and bitter melon were measured. Subsequently, data were analyzed by analysis of variance (ANOVA) and Bonferroni tests using Stata software. Results: The results of the present study showed that a single dose of Momordica charantia fruit extract at doses up to 4000 mg/kg extract does not significant adverse effects on the liver enzymes and tissue structure. Conclusion: Using this drug for short time and low dose has not toxicity effects on liver enzymes activity and tissue structure, hence, it is safe in this range of doses

Evaluation of bred fish and seawater fish in terms of nutritional value, and heavy metals

In many parts of the world consumption of fish and seafood comprises a key proportion of man's diet and health. Despite of having many benefits, eating fish can be dangerous for instance the existence of nonorganic material, especially heavy metals, in some fish is dangerous. There are numerous fish breeding pools across the Lorestan province of Iran and the majority of the people living in these areas consume these kinds of fish, so, we were impelled to carry out a study to compare the nutrients and also heavy metals existent in freshwater fish and seawater fish available to the public across Khorramabad city of Iran. In this cross-sectional study, 9 samples of each five species of freshwater and sea water fish were purchased and their total protein, fat, omega 3, 6, and 9 fatty acids and also their heavy metals content including mercury, lead and cadmium of them were measured. There were no significant differences between mean protein content of the two types of fish. The amount of total fat and omega 3, 6 and 9 fatty acids of freshwater fish was higher than of seawater fish (P>0.001). The levels of cadmium in seawater fish was significantly higher than freshwater fish (P>0.001), and as for the level of mercury and lead, no significant difference was observed between the two types of freshwater fish and seawater fish. According to the results, we recommend that people can secure a part of their protein and unsaturated fatty acids need by consuming freshwater fish

ВПЛИВ ГЛОБАЛЬНИХ РИЗИКІВ НА СВІТОВЕ ТОРГОВЕЛЬНО-ЕКОНОМІЧНЕ СЕРЕДОВИЩЕ

It is noted that the unprecedented dynamic globalization of trade and economic relations and the fourth industrial revolution cardinally transform the global distribution system of the world economy, accompanied by the growing impact of global challenges and risks, the failure to take into account the effects of which permanently reduces the efficiency of economic functioning and international trade. For developing countries affected by geopolitical challenges, the development of partnerships with countries that are recognized as global leaders in the world economy is essential in terms of national interests and the promotion of state sovereignty.The purpose of this paper is to characterize the impact of global risks on the formation and implementation of trade and economic policies of countries based on the methodological approaches of leading international economic institutions and organizations. Major global risks have identified rising / falling prices for assets, oil or gas, changes in the structure of trade and economic cooperation, terrorism, separatism, climate change, unemployment, income inequality, proliferation of weapons of mass destruction, cyberattacks, etc.The following methods of scientific research were used to achieve the goal and to solve the tasks of the article: systematic structural analysis of economic processes and phenomena, method of quantitative and qualitative comparisons, tabular method of calculating the degree of influence.The scientific novelty of the results is to study the processes of formation and implementation of trade and economic policies of countries under the influence of exogenous factors on them. The influence of exogenous factors is characterized not only according to the sectoral classification (economic, geopolitical, technological, social and natural), but also taking into account the degree of influence of the factor (global challenges and global risks) on the environment.It is substantiated that in the conditions of globalization of the world economy, the threats receive a corresponding more serious nature. Therefore, government agencies need to develop new effective tools for their minimization in order to prevent negative effects and to implement more productive trade and economic cooperation with partner countries.Отмечено, что беспрецедентная динамическая глобализация торгово-экономических отношений и четвертая промышленная революция кардинально трансформируют систему распределения мировой экономики сопровождается ростом влияния глобальных вызовов и рисков, неучет действия которых сплошь снижает эффективность функционирования экономик и ведения международной торговли. Для развивающихся стран, подвергающихся воздействию геополитических вызовов, необходимым с точки зрения реализации национальных интересов и отстаивания государственного суверенитета, становится развитие партнерства со странами, которые являются признанными лидерами мировой экономики.Обосновано, что в условиях глобализации мировой экономики угрозы получают соответствующий более серьезный характер. Поэтому правительственным структурам необходимо разработать новые эффективные инструменты их минимизации для предотвращения негативных последствий и реализации более плодотворного торгово-экономического сотрудничества со странами-партнерами.Означено, що безпрецедентна динамічна глобалізація торговельно-економічних відносин та четверта промислова революція кардинально трансформують систему розподілу світової економіки, що супроводжується зростанням впливу глобальних викликів та ризиків, неврахування дії яких суцільно знижує ефективність функціонування економік та ведення міжнародної торгівлі. Для країн, що розвиваються, які зазнають впливу геополітичних викликів, необхідним, з точки зору реалізації національних інтересів та відстоювання державного суверенітету, стає розвиток партнерства з країнами, які є визнаними глобальними лідерами світової економіки.Метою наукової статті є характеристика впливу глобальних ризиків на формування та реалізацію торговельно-економічних політик країн на основі методичних підходів провідних міжнародних економічних інститутів та організацій. Магістральними глобальними ризиками визначено зростання/падіння цін на активи, нафту чи газ, зміни структури торговельно-економічного співробітництва, тероризм, сепаратизм, кліматичні зміни, безробіття, нерівність у доходах, поширення зброї масового знищення, кібератаки тощо.Для досягнення мети і розв’язання завдань статті були використані наступні методи наукового дослідження: системно-структурний аналіз економічних процесів та явищ, метод кількісного та якісного порівнянь, табличний метод розрахунку ступеня впливу.Наукова новизна одержаних результатів полягає у дослідженні процесів формування та реалізації торговельно-економічних політик країн в умовах впливу на них екзогенних факторів. Вплив екзогенних факторів охарактеризований не тільки відповідно до секторальної класифікації (економічні, геополітичні, технологічні, соціальні та природні), а й з урахуванням ступеня впливу фактору (глобальні виклики та глобальні ризики) на середовище.Обґрунтовано, що в умовах глобалізації світової економіки загрози отримують відповідний більш серйозний характер. Тому урядовим структурам необхідно розробити нові ефективні інструменти їх мінімізації задля запобігання негативних наслідків та реалізації більш плідного торговельно-економічного співробітництва з країнами-партнерами

Joint Adaptive Modulation-Coding and Cooperative ARQ for Wireless Relay Networks

This paper presents a cross-layer approach to jointly design adaptive modulation and coding (AMC) at the physical layer and cooperative truncated automatic repeat request (ARQ) protocol at the data link layer. We first derive an exact closed form expression for the spectral efficiency of the proposed joint AMC-cooperative ARQ scheme. Aiming at maximizing this system performance measure, we then optimize an AMC scheme which directly satisfies a prescribed packet loss rate constraint at the data-link layer. The results indicate that utilizing cooperative ARQ as a retransmission strategy, noticeably enhances the spectral efficiency compared with the system that employs AMC alone at the physical layer. Moreover, the proposed adaptive rate cooperative ARQ scheme outperforms the fixed rate counterpart when the transmission modes at the source and relay are chosen based on the channel statistics. This in turn quantifies the possible gain achieved by joint design of AMC and ARQ in wireless relay networks.Comment: 5 pages, 4 figures, To appear in the Proceedings of the 2008 IEEE International Symposium on Wireless Communication Systems (ISWCS), Rykevick, Island, Oct 200