Future time perspective and leisure activities during the COVID-19 pandemic period

This study examines the effect of future time perspective and risk attitude on leisure activities during the COVID-19 pandemic period, using the data from the 2020 Taiwan Social Change Survey. We show that people with high future time perspective tend to reduce the frequency of out-of-home leisure activities, whereas increase at-home online activities. The results indicate that, other than risk consideration, how people sense time plays a crucial role on the choices of leisure activities.

Immunogenicity of a spike protein subunit-based COVID-19 vaccine with broad protection against various SARS-CoV-2 variants in animal studies.

SARS-CoV-2 pandemic has profound impacts on human life and global economy since the outbreak in 2019. With the new variants continue to emerge with greater immune escaping capability, the protectivity of the available vaccines is compromised. Therefore, development a vaccine that is capable of inducing immunity against variants including omicron strains is in urgent need. In this study, we developed a protein-based vaccine BCVax that is consisted of antigen delta strain spike protein and QS21-based adjuvant AB801 in nanoparticle immune stimulation complex format (AB801-ISCOM). Results from animal studies showed that high level of anti-S protein IgG was induced after two doses of BCVax and the IgG was capable of neutralizing multiple variants of pseudovirus including omicron BA.1 or BA.2 strains. In addition, strong Th1 response was stimulated after BCVax immunization. Furthermore, BCvax with AB801-ISCOM as the adjuvant showed significant stronger immunity compared with the vaccine using aluminum hydroxide plus CpG 1018 as the adjuvant. BCVax was also evaluated as a booster after two prior vaccinations, the IgG titers and pseudovirus neutralization activities against BA.2 or BA.4/BA.5 were further enhanced suggesting BCVax is a promising candidate as booster. Taken together, the pre-clinical data warrant BCVax for further development in clinic.

A computational framework for transmission risk assessment of aerosolized particles in classrooms.

Infectious airborne diseases like the recent COVID-19 pandemic render confined spaces high-risk areas. However, in-person activities like teaching in classroom settings and government services are often expected to continue or restart quickly. It becomes important to evaluate the risk of airborne disease transmission while accounting for the physical presence of humans, furniture, and electronic equipment, as well as ventilation. Here, we present a computational framework and study based on detailed flow physics simulations that allow straightforward evaluation of various seating and operating scenarios to identify risk factors and assess the effectiveness of various mitigation strategies. These scenarios include seating arrangement changes, presence/absence of computer screens, ventilation rate changes, and presence/absence of mask-wearing. This approach democratizes risk assessment by automating a key bottleneck in simulation-based analysis-creating an adequately refined mesh around multiple complex geometries. Not surprisingly, we find that wearing masks (with at least 74% inward protection efficiency) significantly reduced transmission risk against unmasked and infected individuals. While the use of face masks is known to reduce the risk of transmission, we perform a systematic computational study of the transmission risk due to variations in room occupancy, seating layout and air change rates. In addition, our findings on the efficacy of face masks further support use of face masks. The availability of such an analysis approach will allow education administrators, government officials (courthouses, police stations), and hospital administrators to make informed decisions on seating arrangements and operating procedures. Supplementary Information: The online version contains supplementary material available at 10.1007/s00366-022-01773-9.

A computational framework for transmission risk assessment of aerosolized particles in classrooms

Infectious airborne diseases like the recent COVID-19 pandemic render confined spaces high-risk areas. However, in-person activities like teaching in classroom settings and government services are often expected to continue or restart quickly. It becomes important to evaluate the risk of airborne disease transmission while accounting for the physical presence of humans, furniture, and electronic equipment, as well as ventilation. Here, we present a computational framework and study based on detailed flow physics simulations that allow straightforward evaluation of various seating and operating scenarios to identify risk factors and assess the effectiveness of various mitigation strategies. These scenarios include seating arrangement changes, presence/absence of computer screens, ventilation rate changes, and presence/absence of mask-wearing. This approach democratizes risk assessment by automating a key bottleneck in simulation-based analysis—creating an adequately refined mesh around multiple complex geometries. Not surprisingly, we find that wearing masks (with at least 74% inward protection efficiency) significantly reduced transmission risk against unmasked and infected individuals. While the use of face masks is known to reduce the risk of transmission, we perform a systematic computational study of the transmission risk due to variations in room occupancy, seating layout and air change rates. In addition, our findings on the efficacy of face masks further support use of face masks. The availability of such an analysis approach will allow education administrators, government officials (courthouses, police stations), and hospital administrators to make informed decisions on seating arrangements and operating procedures. Supplementary Information The online version contains supplementary material available at 10.1007/s00366-022-01773-9.

Effects of COVID-19 Control Measures on the Concentration and Composition of PM2.5-Bound Polycyclic Aromatic Hydrocarbons in Shanghai

In order to explore the effects of COVID-19 control measures on the concentration and composition of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs), and to better understand the sources of PM2.5-bound PAHs, PM2.5, samples were collected at two sites in urban and suburban areas of Shanghai before the lockdown, during the lockdown, after the lockdown in 2020, and during the same periods in 2019. The mass concentrations of 21 individual PAHs were determined via GC-MS analysis. While the COVID-19 control measures significantly reduced the absolute concentration of PM2.5-bound PAHs, they had no significant effect on their relative abundances, indicating that the significantly reduced traffic emission may not originally be the major source of PAHs in Shanghai. The differences in the composition of PM2.5-bound PAHs at three different lockdown-related periods may be caused by the gas-particle distribution of semi-volatile PAHs. The similarity in the composition of PM2.5-bound PAHs in different functional areas and different periods brings more uncertainties to the identification of PAH sources using the diagnostic ratios. During the lockdown period, the toxic equivalent concentration of PM2.5-bound PAHs in Shanghai was estimated to decrease by about 1/4, which still exhibits substantial carcinogenic risk upon exposure via inhalation.

Does Background Music Affect Silent Dining Emotions? An Empirical Study of Restaurants during COVID-19.

The music environment of a restaurant is an important factor that affects consumer behaviors during the dining experience, especially silent dining behaviors among people who are not encouraged to talk in the context of COVID-19. This study empirically analyzed the influence of consumers' background music preferences on their emotions and behavioral responses during their dining experience at a high-end Chinese restaurant. A total of 393 valid samples were obtained through purposive sampling and snowball sampling. The research tools used in this study included a personal background information questionnaire, four Oriental and Western music conditions, a background music preference scale, a scale for evaluating emotions during the dining experience, and a behavioral response scale. The results showed that the subjects preferred the Chinese classical music-the Butterfly Lovers Concerto. Background music affected the participants' emotions during their dining experience, and different background music conditions resulted in significant differences in emotions and behaviors. The consumers' emotions, during their dining experience significantly predicted their behaviors under all four music conditions. The greatest contribution and value of this study stem from the finding that the background music at a restaurant can arouse specific positive emotions in consumers during their dining experience and thus affect their eating behavior.

Long-Term Follow-Up Study of COVID-19: Evaluation on Thin-Slice CT

Purpose To retrospectively analyse the CT imaging during the long-term follow-up of COVID-19 patients after discharge. Patients and Methods A total of 122 patients entered the study group. All patients underwent CT examinations. The CT images, which included distribution and imaging signs, were evaluated by two chest radiologists. Laboratory examinations included routine blood work, biochemical testing, and SARS-CoV-2 antibody screening. Statistical methods include chi-square, Fisher’s exact test, one-way analysis of variance, rank sum test and logistic regression by SPSS 17.0. Results There were 22 (18.0%) patients in the mild group, 74 (60.7%) patients in the moderate group, and 26 (21.3%) patients in the severe–critical group. The median follow-up interval was 405 days (378.0 days, 462.8 days). Only monocytes, prothrombin activity, and γ-glutamyltransferase showed significant differences among the three groups. We found that the more severe the patient’s condition, the more SARS-CoV-2 IgG antibodies existed. Only 11 patients (11.0%) showed residual lesions on CT. The CT manifestations included irregular linear opacities in nine cases (9.0%), reticular patterns in six cases (6.0%), and GGOs in five cases (5.0%). Conclusion The proportion of residual lesions on CT in COVID-19 patients was significantly reduced after long-term follow-up. The patients’ age and disease conditions were positively correlated with residual lesions.

Case report: Vaccine-induced immune thrombotic thrombocytopenia complicated by acute cerebral venous thrombosis and hemorrhage after AstraZeneca vaccines followed by Moderna COVID-19 vaccine booster and surgery

Vaccine-induced thrombotic thrombocytopenia (VITT) is a well-known complication of adenoviral vector COVID-19 vaccines including ChAdOx1 nCoV-19 (AstraZeneca) and Ad26. COV2.S (Janssen, Johnson & Johnson). To date, only a few cases of mRNA COVID-19 vaccine such as mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech)-induced VITT have been reported. We report a case of VITT with acute cerebral venous thrombosis and hemorrhage after a booster of mRNA-1273 (Moderna) vaccine in a patient previously vaccinated with two doses of the AstraZeneca vaccine. A 42-year-old woman presented with sudden onset of weakness of the right upper limb with focal seizure. She had received two doses of AstraZeneca vaccines and a booster with Moderna vaccine 32 days before presentation. She had also undergone a laparoscopic myomectomy 12 days previously. Laboratory examinations revealed anemia (9.5 g/dl), thrombocytopenia (31 × 103/μl), and markedly elevated d-dimer (>20.0 mg/L;reference value < 0.5 mg/L). The initial brain computed tomography (CT) was normal, but a repeated scan 10 h later revealed hemorrhage at the left cerebrum. Before the results of the blood smear were received, on suspicion of thrombotic microangiopathy with thrombocytopenia and thrombosis, plasmapheresis and pulse steroid therapy were initiated, followed by intravenous immunoglobulin (1 g/kg/day for two consecutive days) due to refractory thrombocytopenia. VITT was confirmed by positive anti-PF4 antibody and both heparin-induced and PF4-induced platelet activation testing. Clinicians should be aware that mRNA-1273 Moderna, an mRNA-based vaccine, may be associated with VITT with catastrophic complications. Additionally, prior exposure to the AstraZeneca vaccine and surgical procedure could also have precipitated or aggravated autoimmune heparin-induced thrombocytopenia/VITT-like presentation.

Frameshift Mutations in the Microevolution and Macroevolution of Viruses (preprint)

Some nucleotide insertions or deletions (indels) in protein-coding open reading frames lead to frameshift mutations (FSMs) which can change amino acid sequences drastically. FSMs are widely distributed in the genomes of many organisms. However, few studies have been reported regarding frequencies of FSMs in microevolution or macroevolution. Many viruses evolve much more rapidly than cellular organisms, and they are hence suitable to investigate frequencies of FSMs in microevolution or macroevolution. In this report, we identified 667 FSMs in gene sequences of 13 virus families and each FSM changed approximately 11 amino acid residues on average. Of the FSMs, 89.21% were 2-indel compensatory FSMs, and the remaining were 1-, 3-, 4-, 5-indel FSMs. We found that FSMs usually occurred more frequently in the viruses of the same family with smaller sequence identities, and FSMs occurred in the sequences of with identities of 60.0-69.9% more frequently than in the sequences with identities of 90.0-99.9% or 80.0-89.9% by approximately 34.9 or 13.1 times on average. We also found FSMs occurred at different frequencies among genes in the same virus genome, among species in the same virus family, or among virus families (e.g., more frequently in Coronaviridae than in Orthomyxoviridae). These results suggest that FSMs are more frequent in the inter-species or macroevolution than in the intra-species or microevolution of viruses. They provide novel evidence for the hopeful monster hypothesis in evolutionary biology. They inspire researchers to investigate the roles, frequencies, features, and functions of FSMs in other viruses and cellular organisms.

How Risky if China Moves Away from Its Zero-COVID Policy? (preprint)

There are two contrary opinions regarding the risk if mainland China (MC) moves away from its zero-COVID policy. Some experts think the risk shall be much lower than influenza as per MC’s own COVID-19 case fatality rate (CFR), while some other experts think the risk shall be much higher than influenza as per the COVID-19 CFRs of other regions. We elucidate here that this and multiple other striking differences in the CFR between various scenarios all support and substantially resulted from the view that good IDM is highly powerful to mitigate COVID-19, where IDM (isolation-disinfection-maintenance) means isolation of COVID-19 cases from other people, disinfection of their living environments, and health maintenance (e.g., rest, nutrition, breathing). The high effect of good IDM is also supported by the theoretic functions of IDM in minimizing co-infections and maintaining body functions, and the fact that all the 505 COVID-19 deaths reported in MC in 2022 before May 5 died directly of severe underlying diseases with COVID-19. Although it is tough for people in poverty to obtain good IDM, good IDM can be feasible at home for the most mild cases and in hospitals for the most severe cases. Therefore, good IDM can be crucial to mitigating COVID-19 worldwide. It also suggests that the risk for China to end its zero-COVID policy depends on China’s control policies or measures. Based on the effect of IDM, the cautious co-existence policy was proposed for COVID-19 control. This policy could reduce the whole death toll in MC because good IDM is non-specific and can reduce deaths of various other diseases. The cautious co-existence policy (non-specific) and the vaccination policy (specific) aid each other to mitigate COVID-19, and they cannot replace each other. Those who are qualified in health for vaccination should be vaccinated against COVID-19 timely.

Care patterns and TCM constitution as factors of depression and anxiety in systemic scleroderma: a cross- sectional study during the COVID-19 pandemic (preprint)

Background: Care patterns and TCM constitution affects systemic scleroderma (SSc) patients’ emotion and health while the prevalence of covid-19 may aggravate this situation. Thus, we investigated depression and anxiety level in SSc patients during the COVID-19 pandemic to identify the correlation between care patterns, TCM constitution and patients' emotion. Methods: This was a cross-sectional study. SSc patients and healthy individuals were surveyed through the Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, the Constitution in Chinese Medicine Questionnaire and a modified care pattern questionnaire. Factors correlated with depression and anxiety were screened by univariate and multivariate logistic regression. Results: A total of 273 SSc patients and 111 healthy individuals were included. The median age was 45 years in both patient and healthy groups. 74.36% of SSc patients were in depression and 51.65% were in anxiety. 69.60% worked remotely and 50.92% experienced a decrease in income, which were both higher than in the healthy group (38.74%, 29.73%). The proportion of income reduction in the online group (56.19%) was higher than that in the hospital group (33.33%) (P = 0.001). 36.99% of SSc patients had disease progression during the pandemic. Yang-deficiency constitution (82.05%) was the TCM constitution characteristic of SSc patients, while Qi-deficiency(73.63%) and Blood-stasis constitution (57.14%) were also more common. TCM constitution of patients from different sources distributed roughly similar. Qi-deficiency (adjusted OR=2.250) and Qi-stagnation (adjusted OR= 3.824) constitution were significantly associated with depression. The major constitution of dampness-heat was associated with a decrease in depression (adjusted OR=0.160). Remote work during the outbreak (adjusted OR= 1.920), decreasing in income (adjusted OR=3.556), and disease progression (P=0.030) were associated with the occurrence of depression. Conclusion: Chinese SSc patients have a high prevalence of depression and anxiety. The COVID-19 pandemic has changed the care patterns of Chinese SSc patients in terms of work, income, and ways of getting medical support. Within the care patterns, work, income, disease and change of medications were correlates of depression or anxiety in SSc patients. Qi-stagnation and Qi-deficiency constitution were associated with depression, and Qi-stagnation constitution was associated with anxiety in SSc patients. Further research is needed. Trial registration: ChiCTR, ChiCTR2000038796, Registered 02 October 2020, http://www.chictr.org.cn/showproj.aspx?proj=62301

The Application of the Analytic Hierarchy Process Approach to the Inheritance of Local Delicious Food Culture and Development of Sustainable Innovations

Taiwan's agri-food market has been transforming rapidly over the past few years and is struggling with significant food issues and the impact of COVID-19. These include globalization, trade liberalization, population growth, urbanization, policy changes, food consumption patterns and shifts in dietary patterns. Therefore, food security, livelihoods and productive activities that revitalize rural food production and sustained economic growth need to make important contributions to sustainable rural food development. This study adopts the research method of the Analytic Hierarchy Process, employs agricultural experts as the main research object, focuses on the local cuisine in rural Taiwan, and constructs an index model for the inheritance and sustainable innovation and development of local cuisine culture through the opinions of agricultural experts. Accordingly, this study has two objectives. First, we construct indicators of how farmers use local food culture inheritance and sustainable innovation development. Second, we measure the relative weighting of these indicators by agricultural experts in Taiwan. The research results show that a total of 23 indicators in 5 dimensions of the inheritance and sustainable innovation and development of rural local food culture in Taiwan are obtained, of which education and training are the primary indicators of the inheritance and sustainable innovation and development of farmers' local food culture. The biggest contribution of this study is that, in response to the threat of the COVID-19 pandemic and the changes in the inheritance and sustainable development of rural food in Taiwan, this research constructs an indicator model for the inheritance and sustainable development of rural local food culture. It can be used as an important reference for the inheritance and sustainable innovation and development of rural local food culture in Taiwan.

A Computational Framework for Transmission Risk Assessment of Aerosolized Particles in Classrooms (preprint)

The ongoing COVID-19 pandemic has rendered confined spaces as high-risk areas. There is an increasing push to resume in-person activities, for instance, teaching in K-12 and university settings. It becomes important to evaluate the risk of airborne disease transmission while accounting for the physical presence of humans, furniture, and electronic equipment, as well as ventilation. Here, we present a computational framework based on detailed flow physics simulations that allows straightforward evaluation of various seating and operating scenarios to identify risk factors and assess the effectiveness of various mitigation strategies. These scenarios include seating arrangement changes, presence/absence of computer screens, ventilation rate changes, and presence/absence of mask-wearing. This approach democratizes risk assessment by automating a key bottleneck in simulation-based analysis--creating an adequately refined mesh around multiple complex geometries. Not surprisingly, we find that wearing masks (with at least 74% inward protection efficiency) significantly reduced transmission risk against unmasked and infected individuals. The availability of such an analysis approach will allow education administrators, government officials (courthouses, police stations), and hospital administrators to make informed decisions on seating arrangements and operating procedures.

A Pattern New in Every Moment: The Temporal Clustering of Markets for Crude Oil, Refined Fuels, and Other Commodities (preprint)

A suite of clustering methods, applied to the matrix of conditional volatility by trading days and individual assets or asset classes, can identify critical periods in markets for crude oil, refined fuels, and other commodities. Unsupervised machine learning provides a viable alternative to rules-based and subjective definitions of crises in financial markets and the broader economy. Five clustering methods—affinity propagation, mean-shift, spectral, k-means, and hierarchical agglomerative clustering—can identify anomalous periods in commodities trading. These methods identified the financial crisis of 2008–09 and the initial stages of the Covid-19 pandemic. Applied to four energy-related markets—Brent, West Texas intermediate, gasoil, and gasoline—the same methods identified additional periods connected to events such as the September 11 terrorist attacks and the 2003 Persian Gulf war. t-distributed stochastic neighbor embedding facilities the visualization of commodity trading regimes. Future applications of these methods include the definition of bull and bear markets and the identification of recessions and recoveries in the real economy.

Scalable adaptive PDE solvers in arbitrary domains (preprint)

Efficiently and accurately simulating partial differential equations (PDEs) in and around arbitrarily defined geometries, especially with high levels of adaptivity, has significant implications for different application domains. A key bottleneck in the above process is the fast construction of a `good' adaptively-refined mesh. In this work, we present an efficient novel octree-based adaptive discretization approach capable of carving out arbitrarily shaped void regions from the parent domain: an essential requirement for fluid simulations around complex objects. Carving out objects produces an $\textit{incomplete}$ octree. We develop efficient top-down and bottom-up traversal methods to perform finite element computations on $\textit{incomplete}$ octrees. We validate the framework by (a) showing appropriate convergence analysis and (b) computing the drag coefficient for flow past a sphere for a wide range of Reynolds numbers ($\mathcal{O}(1-10^6)$) encompassing the drag crisis regime. Finally, we deploy the framework on a realistic geometry on a current project to evaluate COVID-19 transmission risk in classrooms.