The paper features an analysis of cryptocurrencies and the impact of the COVID- 19 pandemic on their effectiveness as a portfolio diversification tool. It does so by exploring the correlations between the continuously compounded returns on Bitcoin, Ethereum and the S&P500 Index, using a variety of parametric and non-parametric techniques. These methods include linear standard metrics such as the application of ordinary least squares regression (OLS) and the Pearson, Spearman, and Kendall's tau measures of association. In addition, nonlinear, non-parametric measures such as the Generalised Measure of Correlation (GMC), and non-parametric copula estimates are applied. The results across this range of measures are consistent. The metrics suggest that whilst the shock of the COVID-18 pandemic does not appear to have increased the correlations between the crypto currency series, it does appear to have increased the correlations between the returns on crypto currencies and those on the S&P500 Index. This suggests that investment in cryptocurrencies is not likely to offer key diversification strategies in times of crisis, on the basis of evidence provided by this crisis
Sami Qadri; Noora Ahlholm; Ida Lønsmann; Paola Pellegrini; Anni Poikola; Panu K Luukkonen; Kimmo Porthan; Anne Juuti; Henna Sammalkorpi; Anne K Penttilä; +11 more
Sami Qadri; Noora Ahlholm; Ida Lønsmann; Paola Pellegrini; Anni Poikola; Panu K Luukkonen; Kimmo Porthan; Anne Juuti; Henna Sammalkorpi; Anne K Penttilä; Roberta D’Ambrosio; Giorgio Soardo; Diana J Leeming; Morten Karsdal; Johanna Arola; Stergios Kechagias; Serena Pelusi; Mattias Ekstedt; Luca Valenti; Hannes Hagström; Hannele Yki-Järvinen;
Publisher: Linköpings universitet, Avdelningen för diagnostik och specialistmedicin
Project: AKA | Pathogenesis of Non-alcoh... (309263)
Abstract Context Guidelines recommend blood-based fibrosis biomarkers to identify advanced nonalcoholic fatty liver disease (NAFLD), which is particularly prevalent in patients with obesity. Objective To study whether the degree of obesity affects the performance of liver fibrosis biomarkers in NAFLD. Design Cross-sectional cohort study comparing simple fibrosis scores [Fibrosis-4 Index (FIB-4); NAFLD Fibrosis Score (NFS); aspartate aminotransferase to platelet ratio index; BARD (body mass index, aspartate-to-alanine aminotransferase ratio, diabetes); Hepamet Fibrosis Score (HFS)] and newer scores incorporating neo-epitope biomarkers PRO-C3 (ADAPT, FIBC3) or cytokeratin 18 (MACK-3). Setting Tertiary referral center. Patients We recruited overweight/obese patients from endocrinology (n = 307) and hepatology (n = 71) clinics undergoing a liver biopsy [median body mass index (BMI) 40.3 (interquartile range 36.0-44.7) kg/m2]. Additionally, we studied 859 less obese patients with biopsy-proven NAFLD to derive BMI-adjusted cutoffs for NFS. Main Outcome Measures Biomarker area under the receiver operating characteristic (AUROC), sensitivity, specificity, and predictive values to identify histological stage ≥F3 fibrosis or nonalcoholic steatohepatitis with ≥F2 fibrosis [fibrotic nonalcoholic steatohepatitis (NASH)]. Results The scores with an AUROC ≥0.85 to identify ≥F3 fibrosis were ADAPT, FIB-4, FIBC3, and HFS. For fibrotic NASH, the best predictors were MACK-3 and ADAPT. The specificities of NFS, BARD, and FIBC3 deteriorated as a function of BMI. We derived and validated new cutoffs for NFS to rule in/out ≥F3 fibrosis in groups with BMIs <30.0, 30.0 to 39.9, and ≥40.0 kg/m2. This optimized its performance at all levels of BMI. Sequentially combining FIB-4 with ADAPT or FIBC3 increased specificity to diagnose ≥F3 fibrosis. Conclusions In obese patients, the best-performing fibrosis biomarkers are ADAPT and the inexpensive FIB-4, which are unaffected by BMI. The widely used NFS loses specificity in obese individuals, which may be corrected with BMI-adjusted cutoffs.
Publisher: Multidisciplinary Digital Publishing Institute
Project: EC | Respon-SEA-ble (652643)
Education for sustainable development (ESD) is considered vital to the success of the United Nations¿ sustainable development goals. Systems thinking has been identified as a core competency that must be included in ESD. However, systems thinking-orientated ESD learning tools, established methods of the assessment of sustainability skills, and formal trials to demonstrate the effectiveness of such learning tools are all lacking. This research presents a randomised controlled trial (n = 106) to investigate whether an innovative online sustainability learning tool that incorporates two factors, systems thinking and system dynamics simulation, increases the understanding of a specific sustainability problem. A further aim was to investigate whether these factors also support the transfer of knowledge to a second problem with a similar systemic structure. The effects of the two factors were tested separately and in combination using a two-by-two factorial study design. ANOVA and related inferential statistical techniques were used to analyse the effect of the factors on sustainability understanding. Cohen¿s d effect sizes were also calculated. Simulation alone was found to increase ESD learning outcomes significantly, and also to support the transfer of skills, although less significantly. Qualitative feedback was also gathered from participants, most of whom reported finding systems thinking and simulation very helpful. This research was undertaken for the PhD studies of the corresponding author at the National University of Ireland Galway (NUIG) and was supported by funding from ResponSEAble (EU Horizon 2020 project number 652643), Ireland’s Higher Education Authority and Department of Further and Higher Education, Research, Innovation and Science (through the IT Investment Fund and ComputerDISC, and the COVID-19 Costed Extension), and the NUIG PhD Write-Up Bursary. peer-reviewed
In this paper an endeavour was made to evaluate the impact of Covid-19 on the achievement of the investment objectives by selected ETFs in developed and emerging markets. For this purpose, the tracking errors calculated for 18 different ETFs operating on the basis of American, Asian and European stock indexes were analyzed. The time range of the research was selected in such a way as to compare the period before the pandemic(pre-Covid) and the period after the pandemic (post-Covid). The research results show that the outbreak of the coronavirus pandemic has not had a negative impact on the degree of implementation of the investment objective, regardless of the degree of market development. For each of the analyzed markets, the calculated tracking errors were not higher in the post-Covid period as compared to the pre-Covid period. In the vast majority of cases, they were even lower. This means that the management of the ETF has run smoothly in the most turbulent period of the 21st century.
Melkumyan, Hamlet; Fehlings, Susanne; Karrar, Hasan H.; Rudaz, Philippe;
Melkumyan, Hamlet; Fehlings, Susanne; Karrar, Hasan H.; Rudaz, Philippe;
As 2021 draws to a close, Covid-19 continues to prevail worldwide. With the proverbial return to normalcy still appearing distant, there is now a tacit acceptance globally that at least for the foreseeable future, we must live with Covid-19. Given that Covid-19 is an infectious disease—which by definition is transmitted from person to person—the continued prevalence of Covid-19 has implications for how local authorities, communities, and individuals around the world will approach public spaces. While it may be premature to assume a so-called coronacene (see Higgins et al. 2020), going into the future our use of public spaces will be overshadowed by the possibility, even if remote, of illness or death by virtue of close proximity to other individuals. Along with parks and squares, streets and avenues, bazaars constitute ubiquitous public spaces, including in countries of the developing world, such as Armenia and Georgia, our countries of discussion here. Although there is not a clear bifurcation between bazaars and other types of marketplaces, bazaars will usually be comprised of a multitude of nonfranchised, self-owned, small businesses that are variously family-run or rely on family labor. They are usually perceived as chaotic places that lack hygiene (the purportedly unhygienic character of the bazaar was brought to the forefront with the pandemic, given how Covid-19’s origin is widely assumed to be a Wuhan wet market). In Armenia and Georgia, and indeed, across the former Soviet Union, bazaars are a source of employment for the urban and peri-urban population; they also offer goods at price points attractive to a wide demographic. This working paper builds on the premise that the bazaar is an informal institution. Bazaar traders will typically assemble networks by themselves (with manufacturers and wholesalers, buyers and transporters). These networks will usually vary from one business to another. Also, ownership and rent structures are frequently opaque, and the majority of commercial transactions are in cash, which does not appear in state records. As a consequence, for the state, many small businesses do not exist (Fehlings and Karrar 2016, 2020). For those of us researching bazaar trading, Covid-19 has given rise to a basic question: How have independent businesses been transformed by the pandemic? This working paper is an attempt to parse this question in light of developments in Armenia and Georgia. In this working paper, we suggest that the Covid-19 pandemic has deepened informality in the bazaar. That being said, we want to underscore that the present discussion is exploratory. Our ethnography remains limited, and we look forward to returning to the field as soon as it is safe to do so.
This study contributes to the discussion about the impact of the COVID-19 pandemic on the working hours and on the workplace by older workers, aged between 55 and 64. Our aim is to find the factors associated with working more and less hours during the first wave of the pandemic among older workers in Europe. We use data collected by SHARE Corona Survey during the summer of 2020. We estimate two logistic regressions on working more and less hours using a set of individual controls, workplace and a country lockdown control. Our findings show that male workers are less likely to work more hours; older workers are more likely to work less hours; more educated workers work more hours and not less; people with difficulty to meet ends are more often working less hours; worsening of health during the pandemic is associated with working more hours; working home or both home and usual work place are correlated with working more and working less hours. The contribution of this work comes from additional knowledge about the profile of older workers and their changed hours of work during a first wave of COVID-19 in Europe.
Publisher: Multidisciplinary Digital Publishing Institute
AbstractCurrently, airborne transmission is seen as the most important transmission path for SARS-CoV-2. In this investigation, a classic dose-response model is used on the one hand to find out retrospectively the probable viral load of the infectious source patient at the time of transmission in 25 documented outbreaks. We showed that an infection due to airborne transmission at a distance from the infectious person was probably only possible in the 25 outbreaks examined, with attack rates of 4-100%, if the viral load had been higher than 1E+08 viral copies/ml. This demonstrates that the viral load estimated from the swab might overestimate a person’s infectivity via aerosol, because a person is generally considered infectious, independent of the transmission way, when the viral load from the swab is 1E+06 viral copies/ml.On the other hand, a possible approach is presented to predict the probable situational Attack Rate (PARs) of a group of persons in a room through aerosol particles emitted by an infectious source patient. Four main categories of influence on the risk of infection are formed: First the emitted viruses, depending on the viral load and the amount of respiratory particles, and necessary number of reproducible viruses for infection, second the room-specific data and duration of stay of the group of people, third the activity of the exposed persons, and fourth the effect of personal protection (e.g. wearing masks from infectious and/or susceptible person).Furthermore, a simplified method is presented to calculate either the maximum possible number of persons in a room, so that probably a maximum of one person becomes infected when an infectious person is in the room, or the PARs,simple for a given number of persons, ventilation rate and time of occupancy. We additionally show, taking into account organizational preventive measures, which person-related virus-free supply air flow rates are necessary to keep the number of newly infected persons to less than 1. The simple approach makes it easy to derive preventive organizational and ventilation measures. Our results show that the volume flow rate or a person-related flow rate is a much more effective parameter to evaluate ventilation for infection prevention than the air change rate. We suggest to monitor the CO2 concentration as an easy to implement and valid measurement system for indoor spaces.Finally, we show that of the three measures, besides of wearing masks and increasing ventilation, testing contributes the most to the joint protective effect. This corresponds to the classic approach to implement protection concepts: preventing the source from entering the room and emitting viruses at all. In summary, a layered approach of different measures is recommended to mutually compensate for possible failures of any one measure (e.g. incorrect execution of tests, incorrect fit of masks or irregular window opening), to increase the degree of protection and thus reduce the risk of transmission of SARS-CoV-2.
Publisher: Multidisciplinary Digital Publishing Institute
The COVID-19 outbreak is associated with sleep problems and mental health issues among individuals. Therefore, there is a need to assess sleep efficiency during this tough period. Unfortunately, the commonly used instrument on insomnia severity—the Insomnia Severity Index (ISI)—has never been translated and validated among Bangladeshis. Additionally, the ISI has never been validated during a major protracted disaster (such as the COVID-19 outbreak) when individuals encounter mental health problems. The present study aimed to translate the ISI into Bangla language (ISI-Bangla) and validate its psychometric properties. First, the linguistic validity of the ISI-Bangla was established. Then, 9790 Bangladeshis (mean age = 26.7 years; SD = 8.5; 5489 [56.1%] males) completed the Bangla versions of the following questionnaires: ISI, Fear of COVID-19 Scale (FCV-19S), and Patient Health Questionnaire-9 (PHQ-9). All the participants also answered an item on suicidal ideation. Classical test theory and Rasch analyses were conducted to evaluate the psychometric properties of the ISI-Bangla. Both classical test theory and Rasch analyses support a one-factor structure for the ISI-Bangla. Moreover, no substantial differential item functioning was observed across different subgroups (gender, depression status (determined using PHQ-9), and suicidal ideation). Additionally, concurrent validity of the ISI-Bangla was supported by significant and moderate correlations with FCV-19S and PHQ-9; known-group validity was established by the significant difference of the ISI-Bangla scores between participants who experienced suicidal ideation and those without. The present psychometric validation conducted during the COVID-19 outbreak suggests that the ISI-Bangla is a promising and operationally adequate instrument to assess insomnia in Bangladeshis.
Kathrine Jáuregui Renaud; Davis Cooper-Bribiesca; Elizabet Martínez-Pichardo; José A. Miguel Puga; Dulce M. Rascón-Martínez; Luis A. Sánchez Hurtado; Tania Colin Martínez; Eliseo Espinosa-Poblano; Juan Carlos Anda-Garay; Jorge I. González Diaz; +2 more
Kathrine Jáuregui Renaud; Davis Cooper-Bribiesca; Elizabet Martínez-Pichardo; José A. Miguel Puga; Dulce M. Rascón-Martínez; Luis A. Sánchez Hurtado; Tania Colin Martínez; Eliseo Espinosa-Poblano; Juan Carlos Anda-Garay; Jorge I. González Diaz; Etzel Cardeña; Francisco Avelar Garnica;
The COVID-19 pandemic has provoked generalized uncertainty around the world, with health workers experiencing anxiety, depression, burnout, insomnia, and stress. Although the effects of the pandemic on mental health may change as it evolves, the majority of reports have been web-based, cross-sectional studies. We performed a study assessing acute stress in frontline health workers during two consecutive epidemic waves. After screening for trait anxiety/depression and dissociative experiences, we evaluated changes in acute stress, considering resilience, state anxiety, burnout, depersonalization/derealization symptoms, and quality of sleep as cofactors. During the first epidemic wave (April 2020), health workers reported acute stress related to COVID-19, which was related to state anxiety. After the first epidemic wave, acute stress decreased, with no increase during the second epidemic wave (December 2020), and further decreased when vaccination started. During the follow-up (April 2020 to February 2021), the acute stress score was related to bad quality of sleep. However, acute stress, state anxiety, and burnout were all related to trait anxiety/depression, while the resilience score was invariant through time. Overall, the results emphasize the relevance of mental health screening before, during, and after an epidemic wave of infections, in order to enable coping during successive sanitary crises.
Only a mere fraction of the huge variety of human pathogenic viruses can be targeted by the currently available spectrum of antiviral drugs. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has highlighted the urgent need for molecules that can be deployed quickly to treat novel, developing or re-emerging viral infections. Sulfated polysaccharides are found on the surfaces of both the susceptible host cells and the majority of human viruses, and thus can play an important role during viral infection. Such polysaccharides widely occurring in natural sources, specifically those converted into sulfated varieties, have already proved to possess a high level and sometimes also broad-spectrum antiviral activity. This antiviral potency can be determined through multifold molecular pathways, which in many cases have low profiles of cytotoxicity. Consequently, several new polysaccharide-derived drugs are currently being investigated in clinical settings. We reviewed the present status of research on sulfated polysaccharide-based antiviral agents, their structural characteristics, structure–activity relationships, and the potential of clinical application. Furthermore, the molecular mechanisms of sulfated polysaccharides involved in viral infection or in antiviral activity, respectively, are discussed, together with a focus on the emerging methodology contributing to polysaccharide-based drug development.