ABSTRACT
Purpose: The purpose of this study is to investigate connectedness between the four main GCC stock markets (Saudi Arabia, United Arab Emirates, and Oman) and two major cryptocurrencies i.e. Bitcoin and Ethereum. The outcome of the research will help in identifying the diversification in these markets during crises like Covid-19. Design/methodology/approach: The study has used Augmented Dickey-Fuller Test (ADF) and Phillips-Perron test (PP) to test stationary of data, pairwise Granger causality test, followed by variance decomposition test of vector auto-regression (VAR) model to investigate the linkages between the stock markets and cryptocurrencies under study. Descriptive statistics and graphs were used to study the volatility behavior of markets before, during, and after Covid-19. Finding(s): Results showed that volatility was highest for Bitcoin and Ethereum throughout the study period as compared to stock indices. Oman stock indices were found to be a source of diversified investment. During covid Bitcoin and Ethereum were highly endogenous. Dubai Financial Market (DFM) was found highly connected to all indices during covid. Hence, Bitcoin, Ethereum, and DFM do not provide a diversification choice to investors. High linkages were found in all other markets under this study. Connectedness between the stock indices increased during covid. Lastly, series in the study moved to their normal pattern after the covid. Research limitations/implications: The study has the scope to be extended to capture the effects of regulations on cryptocurrencies' performance. The results of the study may well help firms and investors to understand the GCC stock market behavior during pandemics and find out diversification choices in these markets. Originality/value: Investigating the pattern and connectedness of GCC stock markets and cryptocurrencies with reference to the Covid-19 Pandemic is the originality of this study. Copyright © 2022 Wolters Kluwer Medknow Publications. All rights reserved.
ABSTRACT
The liver-derived hormone hepcidin, a member of the defensin family of antimicrobial peptides, plays an important role in host defense and innate immunity due to its broad antibacterial and antiviral properties. Ferritin, an iron storage protein is often associated with iron deficiency, hypoferritinemia, hypoxia, and immune complications, which are all significant concerns for systemic infection in Alzheimer's disease (AD) and Down's syndrome (DS) dementia. Serum and post-mortem brain samples were collected from AD, DS and age-matched control subjects. Serum samples were analyzed with ELISA for ferritin, hepcidin and IL-6. Additionally, post-mortem brain sections were assessed by immunohistochemistry for iron-related and inflammatory proteins. A significant increase in serum hepcidin levels was found in DS, compared to controls and AD subjects (p < 0.0001). Hepcidin protein was visible in the epithelial cells of choroid plexus, meningeal macrophages and in the astrocytes close to the endothelium of blood vessels. Hepcidin co-localized with IL-6, indicating its anti-inflammatory properties. We found significant correlation between hypoferritinemia and elevated levels of serum hepcidin in AD and DS. Hepcidin can be transported via macrophages and the majority of the vesicular hepcidin enters the brain via a compromised blood brain barrier (BBB). Our findings provide further insight into the molecular implications of the altered iron metabolism in acute inflammation, and can aid towards the development of preventive strategies and novel treatments in the fight against neuroinflammation.