128 research outputs found
The impact of petroleum exporting countries’ membership of the World Trade Organisation on their economic development with an emphasis on the export dependency of these nations on crude oil
In the mid-1990s, most nations, including some major oil exporting countries, joined the World Trade Organisation (WTO) to create a global trading system that was more integrated than ever before. The basic motive behind membership of this organisation was economic growth and industrialisation based on international trade. The theoretical underpinnings which support the idea can be found in the literature review, yet despite these considerable efforts, the trade-development or industrialisation relationship still remains quite ambiguous. In this research we study industrialisation in selected oil exporting nations after they became members of the WTO based on a two-phase analysis approach. In the first stage, we investigate the change in crude oil share in the total annual exports of these nations as the crude oil export ratio (CER) which has been very high, and in the second phase we study export portfolio diversification as an industrialisation index. In fact, the considerable share of crude petroleum in the export portfolio of these countries persuades us to ask whether or not they have successfully changed their comparative advantage from primary to manufactured goods after WTO membership to maximise their benefits from international trade. To examine the change in the industrialisation level in oil exporting countries in two different time periods before and after membership of the WTO, we utilise the crude oil export ratio (CER) for the first phase and a variant of the Balassa revealed comparative advantage (RCA) measure for the second. The CER, tells us to what extent these nations have reduced (or may have increased) their economic dependency on crude petroleum exports after their membership of the WTO. Indeed, a high rate of such a dependency would not only create a more risky export portfolio in international trade but also could be considered as an important characteristic of underdeveloped or even non-industrialised economies. In simple terms, a meaningful shift in the comparative advantage from primary to complex commodities’ production could be revealed in the shape of export diversification in these nations. This shift may enable these nations to be industrialised mostly when such activities are accompanied by a meaningful decrease in the CER as a consequence of WTO-led trade liberalisation. Although it is difficult to change the export specialisation pattern in a nation, it initially could be affected by technology absorption, especially when the level of education and institutions created for the purpose of absorbing internationally diffused knowledge are high in a nation. Therefore, the key contribution of this study is to measure the impact of WTO membership using a new – and a much more comprehensive – method for the very first time. This research consists of seven chapters. The first chapter provides a brief explanation of the goals and objectives of the present study. This chapter also includes the methods which will be utilised to investigate the research questions. The history of trade development and industrialisation studies is discussed in the second chapter – as the literature review – to provide the background for the present research. Chapter three focuses on the methodology and its basic foundations to clarify the way which we investigate the research questions. In the fourth chapter we discuss the essential data and also the related data sources which have been utilised to analyse the economic dependency of the countries in the research population on crude petroleum exports. Chapter Five provides the results of CER analyses which indicate what really happened to economic dependency on crude oil in petroleum exporting nations after their membership of the WTO. Initial and terminal revealed symmetric comparative advantage (RSCA) has been analysed systematically based on a Galtonian regression in the sixth chapter to compare the distribution of the RSCA for each nation at two points before and after WTO membership. Finally, with regard to the results of the analyses, the research presents some recommendations in the last chapter
Regression analysis with missing data and unknown colored noise: application to the MICROSCOPE space mission
The analysis of physical measurements often copes with highly correlated
noises and interruptions caused by outliers, saturation events or transmission
losses. We assess the impact of missing data on the performance of linear
regression analysis involving the fit of modeled or measured time series. We
show that data gaps can significantly alter the precision of the regression
parameter estimation in the presence of colored noise, due to the frequency
leakage of the noise power. We present a regression method which cancels this
effect and estimates the parameters of interest with a precision comparable to
the complete data case, even if the noise power spectral density (PSD) is not
known a priori. The method is based on an autoregressive (AR) fit of the noise,
which allows us to build an approximate generalized least squares estimator
approaching the minimal variance bound. The method, which can be applied to any
similar data processing, is tested on simulated measurements of the MICROSCOPE
space mission, whose goal is to test the Weak Equivalence Principle (WEP) with
a precision of . In this particular context the signal of interest is
the WEP violation signal expected to be found around a well defined frequency.
We test our method with different gap patterns and noise of known PSD and find
that the results agree with the mission requirements, decreasing the
uncertainty by a factor 60 with respect to ordinary least squares methods. We
show that it also provides a test of significance to assess the uncertainty of
the measurement.Comment: 12 pages, 4 figures, to be published in Phys. Rev.
The Prevalence of Restless Legs Syndrome in Patients Undergoing Hemodialysis: A Systematic Review and Meta-analysis Study
Introduction: Restless legs syndrome is a sensory-motor disorder that causes sleep disorder. The syndrome in patients undergoing hemodialysis associates with depression, sleep deprivation, performance disorder, day fatigue, excessive daytime sleepiness, stress, anxiety, and higher risk of cardiovascular diseases. The objective of this systematic meta-analysis study was to estimate prevalence of restless legs syndrome in patients undergoing hemodialysis. Methods: Twenty-six relevant articles published between 2000 and 2015 indexed in Iranian (MagIran and IranMedex) and international databases (SID, Google Scholar, ScienceDirect, PubMed, Pre Quest, and Scopus) were selected. Data analysis was carried out through metaanalysis (random effect model) and heterogeneity of the studies was determined using I2 index. The obtained data were analyzed in STAT (11.2). Results: Prevalence of the syndrome according to the found articles was 50 (95 CI: 38-61) in Iranian and 30 (95 CI: 23-37) in international databases. There was an ascending trend of prevalence of the syndrome corresponding to the publication year of the articles (P= 0.419), while the trend based on age of the patients was descending (P= 0.604). However, the variations were not significant. Conclusion: Given the high prevalence and considerable effects of restless legs syndrome on patients undergoing hemodialysis, it is recommended that these patients be screened for the syndrome
The determination of acetaminophen using a carbon nanotube: graphite-based electrode
The oxidation of acetaminophen was studied at a glassy carbon electrode modified with multi-walled carbon nanotubes and a graphite paste. Cyclic voltammety, differential pulse voltammetry and square wave voltammetry at various pH values, scan rates, and the effect of the ratio of nanotubes to graphite were investigated in order to optimize the parameters for the determination of acetaminophen. Square wave voltammetry is the most appropriate technique in giving a characteristic peak at 0.52 V at pH 5. The porous nanostructure of the electrode improves the surface area which results in an increase in the peak current. The voltammetric response is linear in the range between 75 and 2000 ng.mL−1, with standard deviations between 0.25 and 7.8%, and a limit of detection of 25 ng.mL−1. The method has been successfully applied to the analysis of acetaminophen in tablets and biological fluids
Psychometric features of the persian version of self-efficacy tool for patients with hypertension
Background: Hypertension is one of the causes of mortality that can be prevented. Self-efficacy with regard to patients� performance predicts their abilities to change high-risk behaviors. Positive self-efficacy in patients with hypertension predicts compliance, adherence to medications, diet and exercise regimens, and behavioral self-management. Objectives: This study aimed to examine the psychometric features of self-efficacy questionnaire in patients with hypertension. Patients and Methods: In this cross-sectional study, 260 patients with hypertension were selected by multistage cluster sampling in Tehran�s public places to complete the Persian version of hypertension self-efficacy questionnaire. Then, face validity, content, and structure of the questionnaire were evaluated. To determine the reliability of the questionnaire, test-retest method with a two-week interval and Cronbach�s alpha coefficient were used. All data analyses were performed using the SPSS statistical software, version 18.0. Results: According to the results of Content Validity Ratio (CVR), three items were eliminated. The results of exploratory and confirmatory analyses identified three factors, including diet regimen, disease management, and adherence to treatment. The goodness of fit of the three-factor self-efficacy model in patients with hypertension was confirmed based on standard indices (RMSEA = 0.082, NNFI = 0.90, CFI = 0.91, IFI = 0.91, and X2/df = 328.35). Besides, internal consistency of diet regimen, disease management, and adherence to treatment based on Cronbach�s alpha was 0.849, 0.471, and 0.572, respectively. Conclusions: The three-factor structure of the self-efficacy questionnaire showed appropriate validity and reliability in patients with hypertension. Thus, this tool can help caregivers and health service providers assess self-efficacy of hypertensive patients and plan and implement educational and clinical interventions. © 2018, Iranian Cardiovascular Research Journal. All rights reserved
Circular RNAs: New Epigenetic Signatures in Viral Infections
Covalent closed circular RNAs (circRNAs) can act as a bridge between non-coding RNAs and coding messenger RNAs. CircRNAs are generated by a back-splicing mechanism during post-transcriptional processing and are abundantly expressed in eukaryotic cells. CircRNAs can act via the modulation of RNA transcription and protein production, and by the sponging of microRNAs (miRNAs). CircRNAs are now thought to be involved in many different biological and pathological processes. Some studies have suggested that the expression of host circRNAs is dysregulated in several types of virus-infected cells, compared to control cells. It is highly likely that viruses can use these molecules for their own purposes. In addition, some viral genes are able to produce viral circRNAs (VcircRNA) by a back-splicing mechanism. However, the viral genes that encode VcircRNAs, and their functions, are poorly studied. In this review, we highlight some new findings about the interaction of host circRNAs and viral infection. Moreover, the potential of VcircRNAs derived from the virus itself, to act as biomarkers and therapeutic targets is summarized. © Copyright © 2020 Nahand, Jamshidi, Hamblin, Mahjoubin-Tehran, Vosough, Jamali, Khatami, Moghoofei, Baghi and Mirzaei
Chitosan-Based Nanoparticles Against Viral Infections
Viral infections, in addition to damaging host cells, can compromise the host immune system, leading to frequent relapse or long-term persistence. Viruses have the capacity to destroy the host cell while liberating their own RNA or DNA in order to replicate within additional host cells. The viral life cycle makes it challenging to develop anti-viral drugs. Nanotechnology-based approaches have been suggested to deal effectively with viral diseases, and overcome some limitations of anti-viral drugs. Nanotechnology has enabled scientists to overcome the challenges of solubility and toxicity of anti-viral drugs, and can enhance their selectivity towards viruses and virally infected cells, while preserving healthy host cells. Chitosan is a naturally occurring polymer that has been used to construct nanoparticles (NPs), which are biocompatible, biodegradable, less toxic, easy to prepare, and can function as effective drug delivery systems (DDSs). Furthermore, chitosan is Generally Recognized as Safe (GRAS) by the US Food and Drug Administration (U.S. FDA). Chitosan NPs have been used in drug delivery by the oral, ocular, pulmonary, nasal, mucosal, buccal, or vaginal routes. They have also been studied for gene delivery, vaccine delivery, and advanced cancer therapy. Multiple lines of evidence suggest that chitosan NPs could be used as new therapeutic tools against viral infections. In this review we summarize reports concerning the therapeutic potential of chitosan NPs against various viral infections. © Copyright © 2021 Boroumand, Badie, Mazaheri, Seyedi, Nahand, Nejati, Baghi, Abbasi-Kolli, Badehnoosh, Ghandali, Hamblin and Mirzaei
Acute and post-acute phase of COVID-19: Analyzing expression patterns of miRNA-29a-3p, 146a-3p, 155-5p, and let-7b-3p in PBMC
Background: When a new pathogen, such as severe acute respiratory syndrome coronavirus 2, appears all novel information can aid in the process of monitoring and in the diagnosis of the coronavirus disease (COVID-19). The aim of the current study is to elucidate the specific miRNA profile which can act as new biomarkers for distinguishing acute COVID-19 disease from the healthy group and those in the post-acute phase of the COVID-19 disease. Methods: The expression level of selected miRNAs including let-7b-3p, miR-29a-3p, miR-146a-3p and miR-155-5p were evaluated in peripheral blood mononuclear cells (PBMCs) of COVID-19 patients, in both the acute and post-acute COVID-19 phase of the disease and healthy groups, by real-time PCR assays. Specificity and sensitivity of miRNAs was tested by receiver operating characteristic (ROC) analysis in COVID-19 patients. Results: The expression level of all miRNAs in COVID-19 patients was significantly higher than in the healthy group. Therefore, the expression pattern of miR-29a-3p, miR-146a-3p and let-7b-3p in the post-acute COVID-19 phase was significantly different from the acute COVID-19 phase. ROC analyses demonstrated that miR-29a-3p, -155-5p and -146a-3p may serve as the novel biomarker for COVID-19 diagnosis with high specificity and sensitivity. In addition, miR-29a-3p, and -146a-3p can maybe act as novel biomarkers for distinguishing acute from post-acute phase of COVID-19 disease. Discussion: The difference in miRNA expression pattern between COVID-19 patients and those in the healthy group, and between acute COVID-19 with post-acute COVID-19, suggested that cellular miRNAs could be used as promising biomarkers for diagnosis and monitoring of COVID-19. © 2021 Elsevier B.V
Astrophysics with the Laser Interferometer Space Antenna
The Laser Interferometer Space Antenna (LISA) will be a transformative experiment for gravitational wave astronomy, and, as such, it will offer unique opportunities to address many key astrophysical questions in a completely novel way. The synergy with ground-based and space-born instruments in the electromagnetic domain, by enabling multi-messenger observations, will add further to the discovery potential of LISA. The next decade is crucial to prepare the astrophysical community for LISA’s first observations. This review outlines the extensive landscape of astrophysical theory, numerical simulations, and astronomical observations that are instrumental for modeling and interpreting the upcoming LISA datastream. To this aim, the current knowledge in three main source classes for LISA is reviewed; ultra-compact stellar-mass binaries, massive black hole binaries, and extreme or interme-diate mass ratio inspirals. The relevant astrophysical processes and the established modeling techniques are summarized. Likewise, open issues and gaps in our understanding of these sources are highlighted, along with an indication of how LISA could help making progress in the different areas. New research avenues that LISA itself, or its joint exploitation with upcoming studies in the electromagnetic domain, will enable, are also illustrated. Improvements in modeling and analysis approaches, such as the combination of numerical simulations and modern data science techniques, are discussed. This review is intended to be a starting point for using LISA as a new discovery tool for understanding our Universe
How Does It Fit? Exploring the Congruence Between Organizations and Their Corporate Social Responsibility (CSR) Activities
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