WHAT THE COVID-19 PANDEMIC TAUGHT US IN CHILDREN (preprint)

Objective: The COVID-19 pandemic is an important cause of morbidity and mortality, which has had a negative impact worldwide. We aimed to contribute to the medical literature by sharing the knowledge and experience of pediatric patients who were diagnosed as having COVID-19 in a one-year period. Method: Patients aged 1 month to 18 years who were diagnosed as having COVID-19 in our clinic, between March 2020 and April 2020, from when COVID-19 was declared as a pandemic, were included in the study. Results: Four hundred sixty-seven children were included in the study. There were 34 (7.3%) patients under one year of age, 111 (23.8%) between 1-5 years, 98 (30.4%) between 5-10 years, 142 (30.4%) between 11-15 years, and 82 (17.6%) age over 15 years. Fever (88.2%), vomiting (32.4%), and diarrhea (29.4%) in patients aged under 1 year, sore throat (36.6%) in patients aged 11-15 years, and dysgeusia (11%), anosmia (14.6%), headache (18.3%), malaise (40.8%), myalgia (28%), and dyspnea (17.1%) in those aged over 15 years of age were found significantly more common compared with the other age groups. Thirty-five (7.5%) patients were asymptomatic, 365 (78.1%) had mild disease, 35 (7.5%) were moderate, 27 (5.8%) were severe, and five (1.07%) were critical. Leukocyte count, erythrocyte sedimentation rate, ferritin, and C-reactive protein values were significantly higher in hospitalized patients. Four patients died during the study period (0.8%, 4/494). Conclusion: Although COVID-19 has an asymptomatic and mild course in children, it should be kept in mind that it may have a severe course.

On the Risk Spillover from Bitcoin to Altcoins: The Fear of Missing Out and Pump-and-Dump Scheme Effects

This article examines the asymmetric volatility spillover effects between Bitcoin and alternative coin markets at the disaggregate level. We apply a frequency connectedness approach to the daily data of 11 major cryptocurrencies for the period from 1 September 2017 to 2 March 2022. We try to uncover the existence of the "fear of missing out” psychological effect and "pump-and-dump schemes” in the crypto markets. To do that, we estimate the volatility spillovers from Bitcoin to altcoin and the cryptos' own risk spillovers during bull and bear markets. The spillover results from Bitcoin to altcoin provide mixed results regarding the presence of this theory for major cryptocurrencies. However, the empirical findings carried out by the cryptos' own spillover effects fully confirm the existence of a fear-of-missing-out effect and pump-and-dump schemes in all cryptocurrencies except for USDT.

Effects of COVID-19 on cryptocurrency and emerging market connectedness: Empirical evidence from quantile, frequency, and lasso networks

We use time and frequency connectedness approaches based on network analysis to investigate the volatility connectedness among 27 emerging equity markets and seven high-capitalized cryptocurrencies. We estimate the network connectedness using the standard, quantile, frequency, and lasso VAR models for the pre- and post-COVID-19 pandemic periods and daily data over the period from October 2, 2017 to May 20, 2022. The network connectedness estimates based on the several models used in this study indicate a growing risk spillover among and within the emerging market equities and the cryptocurrencies after the COVID-19 pandemic hit the world.  The frequency connectedness analysis shows that cryptocurrencies cannot be used as diversifiers for emerging stock markets in both the short and long-run. The empirical findings from the quantile VAR model reveal that the volatility connectedness in the tails is much stronger compared to the center of the distribution. It is also evident that Saudi Arabia, Thailand’s stock markets, and USDT are the main risk transmitters at the 0.95-th quantile during the post-covid period. Time-varying connectedness estimates confirm the substantial effect of COVID-19. Our study also shows that the spread of risk among these financial markets is global rather than regional, supporting cross-border structure and worldwide financial market integration. The findings suggest cryptocurrency and emerging market equity portfolios should be closely monitored during financial turmoil.

OUTCOMES OF COVID-19 INFECTIONS IN CHILDREN: A SINGLE-CENTER RETROSPECTIVE STUDY (preprint)

Objective: The COVID-19 pandemic is an important cause of morbidity and mortality, which has had a negative impact worldwide. Our aim was to describe clinical findings and outcomes of SARS-CoV-2 viral infection and Covid-19 disease cared for at a large pediatric tertiary care hospital during the first year of the pandemic. Methods: Patients aged 1 month to 18 years who were diagnosed as having COVID-19 between March 2020 and April 2021 were included. The files of patients diagnosed with covid-19 were reviewed retrospectively. Results: 467 children were included in the study. There were 34 (7.3%) patients under one year of age, 111 (23.8%) between 1-5 years, 98 (30.4%) between 5-10 years, 142 (30.4%) between 11-15 years, and 82 (17.6%) age over 15 years. Fever (88.2%), vomiting (32.4%), and diarrhea (29.4%) in patients aged under 1 year, sore throat (36.6%) in patients aged 11-15 years, and dysgeusia (11%), anosmia (14.6%), headache (18.3%), malaise (40.8%), myalgia (28%), and dyspnea (17.1%) in those aged over 15 years of age were found significantly more common compared with the other age groups (p<0.05). Thirty-five (7.5%) patients were asymptomatic, 365 (78.1%) had mild disease, 35 (7.5%) were moderate, 27 (5.8%) were severe, and five (1.07%) were critical. Leukocyte count, erythrocyte sedimentation rate, ferritin, and C-reactive protein values were significantly higher in hospitalized patients. Four patients died during the study period (0.8%, 4/467). Conclusion: While SARS-CoV-2 infection may be asymptomatic and Covid-19 disease usually has a mild clinical course, some children have severe disease or mortality.