Green bonds as hedging assets before and after COVID: A comparative study between the US and China

The COVID pandemic reveals the fragility of the global financial market during rare disasters. Conventional safe-haven assets like gold can be used to hedge against ordinary risks, but tail dependence can substantially reduce the hedging effectiveness. In contrast, green bonds focus on long-term, sustainable investments, so they become an important hedging tool against climate risks, financial risks, as well as rare disasters like COVID. The copula approach based on the TGARCH model is applied to estimate the joint distributions between green bonds and selected financial assets in both US and China. The quantile-based approach is also performed to offer a robustness check on tail dependence. The results show that all assets in the two countries have thick tails and tail dependence with time-varying features. The hedging effectiveness does decline during the COVID pandemic, but it is the hedging effectiveness against tail risks rather than against normal risks. It is argued that green bonds play a significant role in hedging against rare disasters especially in forex markets. It is also found that green bonds in the US and China converge in many aspects, suggesting a smaller cross-country difference than cross-asset difference.

Association between ABO blood groups and COVID-19 infection, severity and demise: A systematic review and meta-analysis.

BACKGROUND AND AIMS: The COVID-19 spreads rapidly around the world which has brought a global health crisis. The pathogen of COVID-19 is SARS-COV-2, and previous studies have proposed the relationship between ABO blood group and coronavirus. Here, we aim to delve into the association between ABO blood group and COVID-19 infection, severity and demise. METHODS: The relevant studies were retrieved from five databases: PubMed, MedRxiv, BioRxiv,Web of Science and CNKI. Members of cases(symptomatic cases, severe cases, died cases) and controls(asymptomatic controls, non-severe controls, alive controls) were extracted from collected studies. Odds ratios (OR) and 95% confidence intervals (CI) were calculated and interpreted from extracted data. Publication bias and sensitivity analysis were also applied to confirm our discovery. RESULTS: Overall 31,100 samples were included in the analysis. Compared to other ABO blood type, an increased odds of infecting COVID-19 among individuals with A blood group (OR: 1.249, 95%CI: 1.114-1.440, P < 0.001) and a decreased odds of infecting COVID-19 among individuals with blood group O (OR: 0.699, 95%CI: 0.635-0.770, P < 0.001) were found. Besides, individuals with blood group AB seems to link a higher risk to COVID-19 severity (OR: 2.424, 95%CI: 0.934-6.294) and demise (OR: 1.348, 95%CI: 0.507-3.583). Meantime, individuals with O blood group might had lower risk to COVID-19 severity (OR: 0.748, 95%CI: 0.556-1.007), and individuals with B blood group were likely to relate a lower risk to COVID-19 demise. CONCLUSIONS: The current meta-analysis suggest that blood type A might be more susceptible to infect COVID-19 while blood type O might be less susceptible to infect COVID-19; there were no correlation between ABO blood group and severity or demise of COVID-19. However, more investigation and research are warranted to clarify the relationship between COVID-19 and ABO blood type.

Mitigating the Impact of COVID-19 on Emergency Stroke Care in Western China (preprint)

Background: The COVID-19 epidemic is still continuing. Little is known about the effects on stroke care. This study aims to investigate the impact of COVID-19 epidemic on urgent stroke treatment in a tertiary stroke center in western China, and to provide reference points for stroke treatment strategies during public health emergencies. Methods: The retrospective, population-based study was conducted in West China Hospital of Sichuan University, the largest hospital in the southwest of China in COVID-19 period (Dec 1, 2019 to Mar 11, 2020) and baseline non-COVID-19 period (Dec 1, 2018 to Mar 11, 2019). The COVID-19 period was further divided into pre- and peak-epidemic stages defined using government data. Medical practice was strictly based on hospital contingency plans and national expert consensus. We compared emergency visits and efficiency of stroke treatment for the baseline and COVID-19 periods. A subgroup analysis was then conducted between pre-and peak-epidemic stages. Findings: Compared with the baseline data, we found no differences in time to deliver acute interventions, intravenous thrombolysis rate (IVT), and neurological improvements in the whole COVID-19 period. There were significant reductions in visits (38·9%, p<0·0001), admission within six hours from onset (13·2%, p=0·001), mild stroke admissions (15·3%, p=0·006) and increases in rates of mechanical thrombectomy (24·4%, p<0·0001) and excellent outcome (18·1%, p<0·01). We observed significantly higher rate of IVT (17·1%, p=0·04) and shorter time to computed tomography scan (22%, p=0·01), during the peak-epidemic stages in subgroup analysis. Interpretation: The hospital’s capacity to deliver high quality stroke emergency care was hardly be affected as a result of comprehensive measures being implemented.The results provide some key messages for the practice of stroke emergency care during a crisis. Funding Statement: National Key R&D Program of China (2018YFC1311400 and 2018YFC1311401).Declaration of Interests: Authors declare no competing interests.Ethics Approval Statement: The study and analysis plan was approved by the ethical review board in West China Hospital of Sichuan University (2019/319). Written informed consent was waived.

Clinical Features of Pregnant Women and Neonates with COVID-19 in Wuhan: a paired comparison study (preprint)

Background Our study aimed to find symptoms unique in pregnancy and to help the early diagnosis in pregnant women and to evaluate the impact of COVID-19 in postpartum women and their newborns.Methods Clinical data were reviewed and collected for 11 pregnant women with laboratory-confirmed COVID-19 who were consecutively admitted to Zhongnan Hospital of Wuhan University and Women and Children’s Hospital of Hubei Province, from Jan 26 to Feb 26, 2020.Results All the confirmed women didn’t have any exposure history and their early symptoms were mildly elevated temperate and fatigue. The chest CT scans of confirmed women can be atypical manifestations, such as bilateral pleural effusions and slightly increased densities. Eight of eleven confirmed women did not feel anything unusual until abnormalities were found on chest CT scans on admission screening test. All three groups had elevated white blood cell count, neutrophil count and lactate dehydrogenase, and reduced total protein.The infection did not increase the risk for premature delivery, premature rupture of membrane, or comorbidities in pregnancy.Conclusions Pregnant women were often asymptomatic and accidentally detected abnormalities on chest CT scan on admission which emphasize the importance of CT scan in prevalent areas of the COVID-19. Even after the laboratory confirmation, the manifestation of the CT scan could be atypical, which alerted the necessity of protection for healthcare workers. The COVID-19 did not increase the risk of complications in pregnant women and their neonates.Trial registration: This case series was approved by the institutional ethics board of Zhongnan Hospital of Wuhan University (No. 2020020) and Women and Children’s Hospital of Hubei Province(NO. LW035).