47 research outputs found
Emergence of world-stock-market network
In the age of globalization, it is natural that the stock market of each
country is not independent form the other markets. In this case, collective
behavior could be emerged form their dependency together. This article studies
the collective behavior of a set of forty influential markets in the world
economy with the aim of exploring a global financial structure that could be
called world-stock-market network. Towards this end, we analyze the
cross-correlation matrix of the indices of these forty markets using Random
Matrix Theory (RMT). We find the degree of collective behavior among the
markets and the share of each market in their structural formation. This
finding together with the results obtained from the same calculation on four
stock markets reinforce the idea of a world financial market. Finally, we draw
the dendrogram of the cross-correlation matrix to make communities in this
abstract global market visible. The dendrogram, drawn by at least thirty
percent of correlation, shows that the world financial market comprises three
communities each of which includes stock markets with geographical proximity
Effect of N-acetyl cysteine on oxidative stress and Bax and Bcl2 expression in the kidney tissue of rats exposed to lead
This study aimed to consider the lead-induced oxidative damage of the kidney of male rats and the role of antioxidant N-acetylcysteine (NAC) in preserving cells against Pb toxicity. Rats were randomly divided into five groups including G1 (control), G2 (single 70 mg/kg dose of Pb), G3 (continuous daily 2 mg/kg dosing of Pb for 4 weeks), G4 (single dose of Pb + 50 mg/kg NAC), and G5 (continuous daily dosing of Pb + 50 mg/kg NAC). The level of malonic dialdehyde (MDA) and total antioxidant capacity were measured spectrophotometrically.The level of Pb in serum and kidney tissue was measured by atomic absorption spectroscopy. Expression of Bax and Bcl2 genes was estimated using RT-PCR. It was shown that single and continuous exposure to Pb caused a considerable increase of Pb content in serum and kidney tissue of rats in G2 and G3 groups compared to other groups. NAC treatment significantly improved TAC values and decreased MDA values in the serum of rats exposed to Pb. Single and continuous Pb dosing caused a 3.9- and 13.1-fold increase in Bax expression and 1.5-fold and 2.1-fold decrease in Bcl2 expression in a kidney tissue respectively. The current study revealed that single and especially continuous Pb exposure was strongly associated with Pb accumulation, antioxidant depletion, oxidative stress and kidney cells apoptosis. NAC can help protect kidney tissue against Pb by elevating antioxidant capacity, mitigating oxidative stress and normalizing Bax and Bcl2 genes expression
Prevalence and risk factors of hepatitis C virus infection in Amol city, north of Iran: A population-Based study (2008-2011)
Background: Hepatitis C Virus (HCV) infection is one of the most important causes of chronic liver disease and related problems in the world.There are few population-based studies on the prevalence and risk factors of hepatitis C infection in Iran, which could not provide enough information. Moreover, the prevalence and risk factors of hepatitis C infection are not similar in all parts of Iran. Objectives: The aim of this survey was to determine the prevalence and risk factors of HCV infection in the general population of the city of Amol, north of Iran. Patients and Methods: This was a population-based study. Using a cluster sampling approach, 6145 individuals of both genders and different ages were involved from general population of urban and rural areas of Amol, The inclusion criteria were Iranian nationality, willing to participate in the study, and lifelong residence in Amol city and surrounding areas. Anti-hepatitis C antibody was measured by a third generation of ELISA. The positive results were confirmed by Recombinant Immuno Blot Assay (RIBA) and quantitative HCV-RNA polymerase chain reaction (PCR) tests. Potential risk factors of HCV transmission were recorded. Results: The mean age of participants was 42.70 ± 17.10 years. Of these participants, 57.2 (n = 3483) were male. Anti-HCV antibody was positive in 12 individuals from which five were RIBA positive. Three of these subjects were PCR positive. The prevalence of HCV was more predominant among males than females. The common risk factors among the study subjects included history of minor or major surgery (34.7), unsterile punctures (21.2), history of traditional phlebotomy (5.8), and history of hepatitis among close relatives (5.7). In univariate regression analysis, unsterile punctures and history of infection in family members were associated with HCV infection. Conclusions: We confirm that in Amol city and surrounding areas, the prevalence of true HCV infection is 0.05, which is lower than that previously reported from Iran. © 2013, Kowsar Corp.; Published by Kowsar Corp
Psychological well-being in Europe after the outbreak of war in Ukraine
The Russian invasion of Ukraine on February 24, 2022, has had devastating effects on the Ukrainian population and the global economy, environment, and political order. However, little is known about the psychological states surrounding the outbreak of war, particularly the mental well-being of individuals outside Ukraine. Here, we present a longitudinal experience-sampling study of a convenience sample from 17 European countries (total participants = 1,341, total assessments = 44,894, countries with >100 participants = 5) that allows us to track well-being levels across countries during the weeks surrounding the outbreak of war. Our data show a significant decline in well-being on the day of the Russian invasion. Recovery over the following weeks was associated with an individual’s personality but was not statistically significantly associated with their age, gender, subjective social status, and political orientation. In general, well-being was lower on days when the war was more salient on social media. Our results demonstrate the need to consider the psychological implications of the Russo-Ukrainian war next to its humanitarian, economic, and ecological consequences
A global experience‐sampling method study of well‐being during times of crisis: The CoCo project
We present a global experience-sampling method (ESM) study aimed at describing, predicting, and understanding individual differences in well-being during times of crisis such as the COVID-19 pandemic. This international ESM study is a collaborative effort of over 60 interdisciplinary researchers from around the world in the “Coping with Corona” (CoCo) project. The study comprises trait-, state-, and daily-level data of 7490 participants from over 20 countries (total ESM measurements = 207,263; total daily measurements = 73,295) collected between October 2021 and August 2022. We provide a brief overview of the theoretical background and aims of the study, present the applied methods (including a description of the study design, data collection procedures, data cleaning, and final sample), and discuss exemplary research questions to which these data can be applied. We end by inviting collaborations on the CoCo dataset
Operating room orchestration by using agent-based simulation
Background: Increasing demand and costs of healthcare services become a serious problem in healthcare systems. Due to the high demand for surgical interventions, operating room (OR) is the heart of hospital with 60�70 of admissions. Operating room resource orchestration as a resource management and performance measurement techniques has considerable effects on its performance. Method: Agent-based simulation is an effective approach to model complex systems. As there are many agents interacting in operating room during a surgery, we can consider an OR as a complex system. In this research, we architected and developed an agent based model considering all different units and actors involving in surgery in the OR. Results: By identifying operating room bottlenecks and consulting with experts, several improving scenarios were developed and finally combined scenario had most effect on total patient waiting time, total patient recovery time and total patient staying at the system by reduction of 9 min, 10 min and 21 min respectively. Conclusion: The result suggested that we can make significant improvements by in-depth understanding of operating room, orchestration concepts and finally doing simulation. © 2019 Elsevier Inc