Analysis and modeling of COVID-19 epidemic dynamics in Saudi Arabia using SIR-PSO and machine learning approaches

INTRODUCTION

COVID-19 has become a global concern because it has extensive damage to health, social and economic systems worldwide. Consequently, there is an urgent need to develop tools to understand, analyze, monitor and control further outbreaks of the disease.

METHODOLOGY

The Susceptible Infected Recovered-Particle SwarmOptimization model and the feed-forward artificial neural network model were separately developed to model COVID-19 dynamics based on daily time-series data reported by the Saudi authorities from March 2, 2020 to February 21, 2021. The collected data were divided into training and validation datasets. The effectiveness of the investigated models was evaluated by using various performance metrics. The Susceptible-Infected-Recovered-Particle-Swarm-Optimization model was found to well predict the cumulative infected and recovered cases and to optimally tune the contact rate and the characteristic duration of the illness. The feed-forward artificial neural network model was found to be efficient in modeling daily new and cumulative infections, recoveries and deaths.

RESULTS

The forecasts provided by the investigated models had high coefficient of determination values of more than 0.97 and low mean absolute percentage errors (around 7% on average).

CONCLUSIONS

Both the Susceptible-Infected-Recovered-Particle-Swarm-Optimization and feed-forward artificial neural network models were efficient in modeling COVID-19 dynamics in Saudi Arabia. The results produced by the models can help the Saudi health authorities to analyze the virus dynamics and prepare efficient measures to control any future occurrence of the epidemic.

COVID-19's Impact on China's Strategic Emerging Industries: An Observation of Policy Difficulties

The study investigates the influence of the COVID-19 on the rate of R&D investment and foreign exchange development of China's most important emerging industry firms. From 2010 to 2020, data were collected from 26 locations across China, focusing on seven different types of critical creating companies. To analyze the data, we have applied Fourier Increased Unit Root Test, Granger causality assessments test, Pattern Assessment test, Poisson pseudo most excellent probability (PPML) approach, Wald test, and Regression analysis test. The results of the tests reveal a clear underlying association among COVID-19 relates Chinese exports and imports. COVID-19's instant effects on imports and exports lack working capital have been calculated, but the short-term, medium-to-long-term products are composite and unidentified. The article result main results are following: (i) The COVID-19 impacts the R&D investment is main industries like as high-end equipment industry, new materials industry, and new-era data innovation. (ii) The COVID-19 highly affects the imports and exports development network of Chinese strategic emerging industries which emphasizes cross-industry grouping features. The study provides the guidance to the future researchers to focus on COVID-19 affects on the strategic emerging industries of developed and underdeveloped countries to determine of foreign direct investment inflow and unemployment growth rates.

JEL: G20, O10, O40

Relationship between working stress and anxiety of medical workers in the COVID-19 situation: A moderated mediation model

BACKGROUND

The COVID-19 pandemic has brought a lot of working stress to medical workers and has a certain impact on their mental health. Working stress is closely related to the increase in anxiety, but few studies have explored whether their relationship will be affected by positive psychological factors in the special situation.

METHODS

798 medical workers were investigated online after the outbreak of the COVID-19 (10 February to 1 March 2020) in China. The relevant questionnaires were used to evaluate working stress, anxiety, sense of control, and psychological capital. The moderated mediation model test was performed using the SPSS software and PROCESS macro program.

RESULTS

Working stress could directly affect anxiety, and indirectly affect anxiety through sense of control. In addition, psychological capital moderated the direct effect of working stress on anxiety, which is more effective at high level of psychological capital. Psychological capital also moderated the second half of the indirect effect of working stress on anxiety, at low level of psychological capital, sense of control was more effective in predicting anxiety.

LIMITATIONS

All the data in this study was collected through online questionnaire. The anxiety response measured in this study cannot be specific to the viral epidemic.

CONCLUSIONS

Under the COVID-19 epidemic situation, for medical workers, low sense of control and low level of psychological capital may be important risk factors of anxiety caused by working stress. Thus, strengthening the sense of control and psychological capital of medical workers would be helpful to reduce their anxiety and maintain their mental health.

Research Note: Gender Differences in Employment During the COVID-19 Epidemic

We investigate the impact of the COVID-19 epidemic on gender disparities in three employment outcomes: labor force participation, full-time employment, and unemployment. Using data from the monthly Current Population Survey, in this research note we test individual fixed-effects models to examine the employment status of women relative to that of men in the nine months following the onset of the epidemic in March of 2020. We also test separate models to examine differences between women and men based on the presence of young children. Because the economic effects of the epidemic coincided with the summer months, when women's employment often declines, we account for seasonality in women's employment status. After doing so, we find that women's full-time employment did not decline significantly relative to that of men during the months following the beginning of the epidemic. Gender gaps in unemployment and labor force participation did increase, however, in the early and later months of the year, respectively. Our findings regarding women's labor force participation and employment have implications for our understanding of the long-term effects of the health crisis on other demographic outcomes.

Effects of tree canopy on psychological distress: A repeated cross-sectional study before and during the COVID-19 epidemic

BACKGROUND

During the COVID-19 epidemic period, people showed a stronger connection to the environment within their communities. Although tree canopy in residential areas has been shown to positively affect psychological distress, it is not clear whether the COVID-19 epidemic played a role in this process. Elucidation of the relationship between tree canopy and the impact on psychological distress during the COVID-19 epidemic could provide valuable information as to the best methods to help individuals cope with urban mental stress events.

METHODS

A total of 15 randomly selected residential areas of Beijing were enrolled in this repeated cross-sectional study. A total of 900 residents were included in the two-waves of the investigation (450 residents per wave) before and during the COVID-19 epidemic (i.e., May 2019 and May 2020). Psychological distress was estimated using the 12-question General Health Questionnaire (GHQ-12). Tree canopy coverage (TCC) was measured through visual interpretation based on the 2013 data sources (World View 2 satellite imagery of Beijing urban areas with a resolution of 0.5 m). The demographic characteristics, distance to the nearest surrounding green or blue space, residential area house price, household density, and construction year were also collected in this study. A multivariate logistic regression, relative risk due to interaction (RERI), and synergy index (SI) were used to explore the relationships among tree canopy, COVID-19, and psychological distress.

RESULTS

The negative impact of the COVID-19 epidemic on mental health was significant, with the prevalence of psychological distress increased 7.84 times (aOR = 7.84, 95% CI = 4.67-13.95) during the COVID-19 epidemic period. Tree canopy coverage in the group without psychological distress was significantly higher than that of the psychologically distressed group (31.07 ± 11.38% vs. 27.87 ± 12.97%, P = 0.005). An increase in 1% of TCC, was related to a 5% decrease in the prevalence of psychological distress (aOR = 0.95, 95% CI = 0.93-0.98). An antagonism joint action between tree canopy and the COVID-19 epidemic existed (RERI = 1.09, 95% CI = 0.72-1.47; SI = 0.16, 95% CI = 0.05-0.52), and persisted enhancing only in medium (26.45%-33.21%) and above TCC level. Correlation of GHQ items and TCC significantly differed between the COVID-19 non-epidemic and epidemic periods, with the effects of tree canopy on GHQ-12 items covering topics, such as social function and depression, presumably absent because of epidemic limitations.

CONCLUSIONS

This study indicates that the COVID-19 epidemic harmed mental health and verified the positive effects of residential tree canopy on psychological distress in Beijing. We suggest paying more attention to residents in areas of low TCC and dealing with psychological distress caused by public health stress events based on tree canopy strategies.

Solidarity and HIV Testing Willingness During the COVID-19 Epidemic: A Study Among Men Who Have Sex With Men in China

Background: Solidarity, such as community connectedness and social cohesion, may be useful in improving HIV testing uptake among men who have sex with men (MSM). This study aimed to evaluate the impact of solidarity on HIV testing before the coronavirus disease 2019 (COVID-19) and HIV testing willingness during COVID-19 among MSM in China. Materials and Methods: An online survey was conducted to collect sociodemographic, sexual behavioral, and solidarity items' information from the participants. We first used factor analysis to reveal the principal component of the solidarity items and then used logistic regression to study the impact of solidarity on HIV testing, by adjusting the possible confounding factors, such as age and education. Results: Social cohesion and community connectedness were revealed by the factor analysis. MSM with high community connectedness were more willing to undergo HIV testing before the epidemic adjusted by age [odds ratio (OR): 1.07, 95% CI: 1.01-1.13]. The community connectedness was also related to the willingness of HIV testing during the epidemic, with adjustments of 1.09 (95% CI: 1.03-1.15). People who did not test for HIV before the COVID-19 epidemic were more willing to have the HIV test during the epidemic, which was correlated with the community connectedness, and the OR value was 1.14 (95%: 1.03-1.25). Conclusion: A high level of community connectedness helped to increase the HIV testing rate before COVID-19 and the willingness of HIV testing during the epidemic among MSM. Strategies can strengthen the role of the community in the management and service of MSM.

[Impact of middle- and long-distance running on mental health in college students in Guangzhou during COVID-19 outbreak]

OBJECTIVE

To investigate the impact of middle- and long-distance running on mental health of students in a college in Guangzhou during the COVID-19 outbreak.

METHODS

We collected data using online questionnaires from the college students selected via snowball sampling. After exclusion of invalid questionnaires and matching the data of running exercise with physical test scores of the participants, 1022 questionnaires were deemed valid for analysis. Of the 1022 students, 869 completed at least a 60-km running distance each semester as required and 153 students did not complete the task. The mental health status of the students was evaluated using PTSD Checklist-Civilian Version (PCL-C), Zung Self-rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS). The scale scores were compared between the students who completed the running task and those who did not, and the factors affecting anxiety and depression were analyzed using univariate analysis and binary logistic regression.

RESULTS

The students who completed the running task had significantly higher physical test scores than those who did not complete the task (P < 0.05). The PCL-C, SDS, SAS scale scores or the conditions of PTSD, anxiety, and depression did not differ significantly between two groups (P>0.05). Binary logistic regression analysis indicated that completing the running task or not did not affect the condition of PTSD, anxiety, or depression of the students; a higher physical test score was associated with a decreased risk of PTSD (OR=0.98, 95%CI: 0.97-0.99) and depression (OR=0.99, 95%CI: 0.97-1.00) but an increased risk of anxiety (OR=1.02, 95%CI: 1.01-1.04) during COVID-19 outbreak.

CONCLUSION

Regular middleand long-distance running exercise may enhance the physical health to indirectly promote the mental health of the college students during COVID-19 outbreak.

The Relationships among Anxiety, Subjective Well-Being, Media Consumption, and Safety-Seeking Behaviors during the COVID-19 Epidemic

The COVID-19 epidemic has been confirmed as the largest scale outbreak of atypical pneumonia since the outbreak of severe acute respiratory syndrome (SARS) in 2003 and it has become a public health emergency of international concern. It exacerbated public confusion and anxiety, and the impact of COVID-19 on people needs to be better understood. Indeed, prior studies that conducted meta-analysis of longitudinal cohort research compared mental health before versus during the COVID-19 pandemic and proved that public health polices (e.g., city lockdowns, quarantines, avoiding gatherings, etc.) and COVID-19-related information that circulates on new media platforms directly affected citizen’s mental health and well-being. Hence, this research aims to explore Taiwanese people’s health status, anxiety, media sources for obtaining COVID-19 information, subjective well-being, and safety-seeking behavior during the COVID-19 epidemic and how they are associated. Online surveys were conducted through new media platforms, and 342 responses were included in the analysis. The research results indicate that the participants experienced different aspects of COVID-19 anxiety, including COVID-19 worry and perceived COVID-19 risk. Among the given media sources, the more participants searched for COVID-19 information on new media, the greater they worried about COVID-19. Furthermore, COVID-19 worry was positively related to safety-seeking behavior, while perceived COVID-19 risk was negatively related to subjective well-being. This paper concludes by offering some suggestions for future studies and pointing out limitations of the present study.

Anxiety and Depression Status and Influencing Factors of MSM in the Post-COVID-19 Epidemic Period: A Cross-Sectional Study in Western China

This study aimed to explore the psychological status and influencing factors of men who have sex with men (MSM) during the stable period of the COVID-19 epidemic, to provide a reference for the mental health counseling of MSM, and to provide a scientific basis for this group to actively respond to public health emergencies. A cross-sectional survey was conducted on the demographic characteristics, epidemic experiences, risk perception, and COVID-19-related attitudes of MSM in western China, and MSM anxiety and depression were assessed by using the Anxiety Self-Rating Scale and the Center for Epidemiological Studies Depression (CES-D) Scale. The incidences of MSM anxiety and depression in the post-COVID-19 epidemic period are 21.7% and 38.0%, respectively. Logistic regression analysis showed that in terms of anxiety, high controllability of the epidemic (OR = 0.7616) is a protective factor. Thinking that they are more susceptible to COVID-19 (OR = 1.6168) and worrying about another outbreak of the epidemic (OR = 1.4793) are risk factors. In terms of depression, being able to protect themselves from being infected with COVID-19 (OR = 0.6280) is a protective factor. The role of anal sex as “0”/“0.5,” and believing that they are more susceptible to COVID-19 (OR = 1.3408) are risk factors. The sudden outbreak affected the psychological state of MSM and even caused negative feelings of anxiety and depression. These findings suggest that prevention and education should be strengthened, and effective intervention measures should be taken as soon as possible, to improve the mental health of MSM.

Andrographolide: A Herbal-Chemosynthetic Approach for Enhancing Immunity, Combating Viral Infections, and Its Implication on Human Health

Plants consistently synthesize and accumulate medically valuable secondary metabolites which can be isolated and clinically tested under in vitro conditions. An advancement with such important phytochemical production has been recognized and utilized as herbal drugs. Bioactive andrographolide (AGL; C20H30O5) isolated from Andrographis paniculate (AP) (Kalmegh) is a diterpenoid lactones having multifunctional medicinal properties including anti-manic, anti-inflammatory, liver, and lung protective. AGL is known for its immunostimulant activity against a variety of microbial infections thereby, regulating classical and alternative macrophage activation, Ag-specific antibody production during immune disorder therapy. In vitro studies with AGL found it to be effective against multiple tumors, neuronal disorders, diabetes, pneumonia, fibrosis, and other diverse therapeutic misadventures. Generally, virus-based diseases like ZIKA, influenza A virus subtype (H1NI), Ebola (EBOV), Dengue (DENV), and coronavirus (COVID-19) epidemics have greatly increased scientific interest and demands to develop more effective and economical immunomodulating drugs with minimal side effects. Trials and in vitro pharmacological studies with AGL and medicinally beneficial herbs might contribute to benefit the human population without using chemical-based synthetic drugs. In this review, we have discussed the possible role of AGL as a promising herbal-chemo remedy during human diseases, viral infections and as an immunity booster.

The Status Quo and Attribution of Wildlife Crimes: A Study of Cases in China From the Perspective of Ecological Economic Ethics

The COVID-19 pandemic, which has ravaged the world, has led to a rethinking of the relationship between humans and nature and the clichés of the economic-centered model. Thus, the ecological economy has been reviewed, especially from an ethical worldview. This paper uses statistical methods to retrieve and categorize 3,646 wildlife crime cases for analysis and quantitative research. It adopts legal and ethical perspectives to analyze the subject and the subjective, incidence, and sentencing factors of wildlife crimes and uses the ecological economic ethical model to measure wildlife crimes. We argue that the existing judicial system fails to answer the difficulties of the economic ethics of wildlife crimes. It is recommended that ecological and economic ethical awareness be internalized. We suggest calling for comprehensive legislation on wildlife crimes from the perspective of ecological economic ethics to effectively prevent and reduce wildlife crime and eventually promote public health.

Estimating the effect of COVID-19 epidemic on shipping trade: An empirical analysis using panel data

The unexpected outbreak of COVID-19 epidemic is an unpredictable event in shipping trade. In this paper, we mainly investigate the gaps that occur in the shipping trade between China and different regions during the period February-October 2020 and to provide useful information for operation management of shipping industry. The data include a panel obtained from the National Statistics Institute to analyze the gap where a selected group of shipping trade in three regions are considered: European Union, North America, and Southeast Asia. On this basis, a dynamic panel data model is proposed to estimate the trend. We observe that government prevention and control measures have a negative impact on export trade, while import trade increases accordingly.

Hybrid Model-Based Simulation Analysis on the Effects of Social Distancing Policy of the COVID-19 Epidemic

This study utilizes modeling and simulation to analyze coronavirus (COVID-19) infection trends depending on government policies. Two modeling requirements are considered for infection simulation: (1) the implementation of social distancing policies and (2) the representation of population movements. To this end, we propose an extended infection model to combine analytical models with discrete event-based simulation models in a hybrid form. Simulation parameters for social distancing policies are identified and embedded in the analytical models. Administrative districts are modeled as a fundamental simulation agent, which facilitates representing the population movements between the cities. The proposed infection model utilizes real-world data regarding suspected, infected, recovered, and deceased people in South Korea. As an application, we simulate the COVID-19 epidemic in South Korea. We use real-world data for 160 days, containing meaningful days that begin the distancing policy and adjust the distancing policy to the next stage. We expect that the proposed work plays a principal role in analyzing how social distancing effectively affects virus prevention and provides a simulation environment for the biochemical field.

Impacts of the COVID-19 epidemic on merchant ship activity and pollution emissions in Shanghai port waters

This study aims to evaluate impacts of the COVID-19 epidemic on merchant ship activities and corresponding atmospheric pollutant emissions in Shanghai port waters. Comparing AIS data from February 2019 and from February 2020, it is found that the merchant ship count and utilization frequency are reduced during the epidemic period. The epidemic could result in longer ship turnaround times because of more operation time for berthing and anchoring activities. Ship emission comparison results reveal that the cargo ship emissions are significantly reduced while container ships and tankers produce a slightly decreased emissions resulting by strict COVID-19 quarantine measures. In addition, the unit ship emission intensity is greatly reduced for ships which are under the normal cruising status while berthing and anchoring operations are associated with increased ship emissions. This implies that it is urgent to promote the use of shore power equipment for merchant ships during the epidemic period.

Telemedicine maybe an effective solution for management of chronic disease during the COVID-19 epidemic

Aim:

Based on the development of telemedicine and the experience of using it during the COVID-19 epidemic, we aimed to explore its convenience and shortcomings to provide a reference for the further improvement of telemedicine.

Background:

Traditional healthcare has been significantly affected by the outbreak of COVID-19, which has increased fear in patients with chronic diseases and increased the difficulty of obtaining hospitalized treatment.

Methods:

This is a conceptual article. The literature search is based on Pubmed, including articles published between January 2015 and December 2020. The purpose was to determine whether telemedicine is effective in the management of chronic diseases in the epidemic situation and to develop telemedicine and chronic disease management for long-term epidemic situations in the future.

Findings:

Telemedicine has demonstrated its advantages during the COVID-19 epidemic and can provide diversified clinical care services for patients with chronic diseases; these services have played a vital role in epidemic prevention and control, greatly alleviated the shortage of medical resources, increased the utilization level of medical resources, and reduced the cross-infection risk during treatment in hospitals. Furthermore, the epidemic situation presents opportunities for the development of diagnosis and treatment methods via the internet and active health management modalities.

Application of a Cloud Video Conference Method for Recruiting Healthy Subjects Into an Early-Phase Clinical Trial During the COVID-19 Pandemic

Objective: Our objective is to explore the effect of applying cloud video conferencing methods to the informed consent process in an early-phase clinical trial during the COVID-19 pandemic.

Methods: All participants who intended to participate in the trial were informed via a cloud video conference before signing the informed consent forms (ICF). Then, the attitudes of the participants with the cloud video conference and their understanding of the trial were evaluated using a questionnaire when they visited to sign the ICF onsite.

Results: A total of 165 subjects participated in the cloud video conference process, and 142 visited the site to sign and date the ICFs at the center during the appointment time. The survey showed that nearly 100% of the subjects evaluated the video-based informed consent process as very good or good and gave correct answers to questions about the trial. Furthermore, 136 (95.8%) subjects believed that the knowledge about the trial derived via the video-based informed consent process was consistent with the onsite reality, and 139 (97.9%) subjects expressed their willingness to participate in an informed consent procedure undertaken through an online video conference.

Conclusions: The video-based informed consent process achieved the same effects as an onsite informed consent process. The former saves time and cost of transportation for the subject and exhibits good public acceptance; especially in light of the COVID-19 pandemic, this process is conducive for reducing the risk of subject infection due to travel and would also help avoid crowding on site.

Improvement to the subjective well-being of pet ownership may have positive psychological influence during COVID-19 epidemic

The COVID-19 epidemic and government intervention measures may have adverse effects on people's mental health. To explore the influence of pets on the intervention of people's psychological problems during the COVID-19 epidemic, an online survey was carried out between April 9 and April 29, 2020. A total of 756 participants replied to this questionnaire. Mental health variables were assessed, and the comparison of behavior changes among pet owners and pets on positive mental well-being during COVID-19 epidemic. Comparative analysis was performed; compared with individuals without pets (n = 575), pet owners (n = 181) had a higher prevalence of insomnia (p = 0.006). Living in Wuhan city was a risk factor for people with psychological stress (p < 0.05). Dog owners exhibited lower than average scores of insomnia and uncertainty of infection than cat owners (p = 0.004). People with more than one pet exhibited lower than average scores of depression than having one pet (p = 0.040). For analysis of psychological effects of pets on people, the role of pets in subjective feeling and positive psychological changes of pet owner was significantly different. Pet owners relieve that psychological pressure through behavioral changes towards their pets in early stage. Pets provided positive subjective well-being and psychological effects for their owners.

Stressful events and adolescents' suicidal ideation during the COVID-19 epidemic: A moderated mediation model of depression and parental educational involvement

This study examined the association between stressful events and adolescents' suicidal ideation and determined the roles of depression as a mediator and parental educational involvement as a moderator during the COVID-19 epidemic. Survey data from a sample of 1595 Chinese adolescents and their parents were subjected to path analysis. The results indicated that stressful events of the COVID-19 epidemic were significantly positively associated with adolescents' suicidal ideation, and this association was mediated by depression. In addition, adolescents' parental educational involvement significantly moderated the path from depression to suicidal ideation. These results highlight the importance of identifying the underlying key mechanisms that moderate the mediated paths between stressful events and adolescents' suicidal ideation during the COVID-19 epidemic. The findings also provide implications for parents and education staff regarding the importance of improving parental educational involvement to prevent adolescents' suicidal ideation during the COVID-19 epidemic.

[Impacts of Meteorology and Emission Variations on PM2.5 Concentration Throughout the Country During the 2020 Epidemic Period]

This study analyzed the impacts of meteorological conditions and changes in air pollutant emissions on PM_2.5 across the country during the first quarter of 2020 based on the WRF-CMAQ model. Results showed that the variations in meteorological conditions led to a national PM_2.5 concentration decreased of 1.7% from 2020-01 to 2020-03, whereas it increased by 1.6% in January and decreased by 1.3% and 7.9% in February and March, respectively. The reduction of pollutants emissions led to a decrease of 14.1% in national PM_2.5 concentration during the first quarter of 2020 and a decrease of 4.0%, 25.7%, and 15.0% in January, February, and March, respectively. Compared to the same period last year, the PM_2.5 concentration measured in Wuhan City decreased more than in the entire country. This was caused by improved meteorological conditions and a higher reduction of pollutant emissions in Wuhan City. PM_2.5 in Beijing increased annually before the epidemic outbreak and during the strict control period, mainly due to unfavorable meteorological conditions. However, the decrease in PM_2.5 in Beijing compared to March 2019 was closely related to the substantial reduction of emissions. The measured PM_2.5 in the "2+26" cities, the Fenwei Plain and the Yangtze River Delta (YRD) decreased during the first quarter of 2020, with the largest drop occurring in the Yangtze River Delta due to higher YRD emissions reductions. The meteorological conditions of "2+26" cities and Fenwei Plain were unfavorable before the epidemic outbreak and greatly improved during the strict control period, whereas the Yangtze River Delta had the most favorable meteorological conditions in March. The decrease in PM_2.5 concentration caused by the reduction of pollutant emissions in the three key areas was highest during the strict control period.

State estimation-based control of COVID-19 epidemic before and after vaccine development

In this study, a nonlinear robust control policy is designed together with a state observer in order to manage the novel coronavirus disease (COVID-19) outbreak having an uncertain epidemiological model with unmeasurable variables. This nonlinear model for the COVID-19 epidemic includes eight state variables (susceptible, exposed, infected, quarantined, hospitalized, recovered, deceased, and insusceptible populations). Two plausible scenarios are put forward in this article to control this epidemic before and after its vaccine invention. In the first scenario, the social distancing and hospitalization rates are employed as two applicable control inputs to diminish the exposed and infected groups. However, in the second scenario after the vaccine development, the vaccination rate is taken into account as the third control input to reduce the susceptible populations, in addition to the two objectives of the first scenario. The proposed feedback control measures are defined in terms of the hospitalized and deceased populations due to the available statistical data, while other unmeasurable compartmental variables are estimated by an extended Kalman filter (EKF). In other words, the susceptible, exposed, infected, quarantined, recovered, and insusceptible individuals cannot be identified precisely because of the asymptomatic infection of COVID-19 in some cases, its incubation period, and the lack of an adequate community screening. Utilizing the Lyapunov theorem, the stability and bounded tracking convergence of the closed-loop epidemiological system are investigated in the presence of modeling uncertainties. Finally, a comprehensive simulation study is conducted based on Canada's reported cases for two defined timing plans (with different treatment rates). Obtained results demonstrate that the developed EKF-based control scheme can achieve desired epidemic goals (exponential decrease of infected, exposed, and susceptible people).

Differential Psychological Factors Associated With Unnecessary Dental Avoidance and Attendance Behavior During the Early COVID-19 Epidemic

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 is challenging the dental community to an unprecedented degree. Knowledge of the increased risk of infection in dental settings has been disseminated to the public and guidelines have been formulated to assist dental attendance decision-making. However, dental attendance behaviors incompatible with treatment need is not uncommon in clinical settings. Important gaps remain in the knowledge about how psychological factors are affecting dental attendance behaviors during the COVID-19 epidemic. In this cross-sectional study, a questionnaire survey was performed during February and March 2020. A total of 342 and 294 dental patients who attended and avoided dental visits, respectively, were included. The participants were classified into four groups based on dental attendance behavior and emergent/urgent dental treatment need. Bivariate analysis was performed to investigate factors associated with dental attendance. Multivariable logistic regression based on principal component scores was performed to identify major psychological constructs associated with unnecessary dental avoidance and attendance. Among all the factors explored, inability to wear masks during dental treatment (P < 0.001; effect size: 0.32) was most closely associated with the overall pattern of dental attendance among participants. Multivariable regression suggested that unnecessary dental avoidance was associated with perceived risk of infection in general and in dental settings (odds ratio [95% CI]: 0.62 [0.53, 0.72]; p < 0.001), perceived impact of COVID-19 and dental problems on general health (0.79 [0.65, 0.97]; 0.021), and personal traits such as trust and anxiety (0.77 [0.61, 0.98]; 0.038). Unnecessary dental attendance was associated with optimism toward the epidemic (1.68 [1.42, 2.01]; <0.001) and trust (1.39 [1.13, 1.74]; 0.002). Multidisciplinary efforts involving dental and medical professionals as well as psychologists are warranted to promote more widespread adoption, among the general public, of dental attendance behaviors compatible with dental treatment need during the COVID-19 epidemic.

Impact of social lockdown due to COVID-19 on environmental and health risk indices in India

Coronavirus disease (COVID-19) spread across the globe through the human transmission. The World Health Organization suggested social distancing to curb the community spread. After national social lockdown started in India, air quality improved drastically. This further hypothesized to influence the environment and human health, and this study is positively the first to weigh it using multiple indices. The calculated environmental indices are photochemical ozone creation potential (POCP), acidification potential (AP), and eutrophication potential (EP). The cancer risk, chronic health index (CHI), and acute health index (AHI) were considered to calculate the health risk. The spatial trend change in the air pollution reflecting on these indices are calculated for four Indian megacities Delhi, Bangalore, Hyderabad, and Kolkata. Temporal variation was accounted for monthly (2019 vs 2020), one-week and two-weeks period during the social lockdown. The results showed a significant decrease in environmental and health risk during the lockdown due to a corresponding decrement in air pollution. The decrease in the particulate matter was found to play a vital role in altering the air pollution mediated risks of interest. Delhi showed a maximum difference in POCP and Acute HI by recording a dip of 70.79% and 43.53% respectively in 2020 during lockdown. The maximum reduction in health risk indices was 41%, 31%, 17%, 19% for Delhi, Bangalore, Hyderabad, and Kolkata. Bangalore recorded the maximum decline in EP, Cancer risk, Chronic HI by 66.66%, 58.62%, and 58.76% in 2020 compared to 2019. A maximum fall in AP was seen in Kolkata by 57.23% in 2020 among all cities. The connection between these drop-in indices and the cause of air pollutants were well discussed. This present paper gives more in-depth insights into air pollution's effect on environmental and health parameters by connecting and converging various air pollution aspects into a single scale. This study also enlightens the importance of controlling air pollution to have a better environment and healthy life to attain sustainable development.

Mindfulness training on the resilience of adolescents under the COVID-19 epidemic: A latent growth curve analysis

As a preventive measure during the COVID-19 epidemic, we have had to stay at home for a long time. The lifestyle of adolescents has undergone severe changes. Almost every school started online education for the first time. Some adolescents have shown low resilience when faced with these changes. Most previous research has focused on mindfulness training and resilience by using cross-sectional or two-point tracking designs. However, little is known about the developmental trajectories of the impact of mindfulness training on resilience, particularly during this epidemic. Therefore, this study aims to explore how the developmental trajectories of resilience are impacted by mindfulness training. After administering the CD-RISC, we recruited 90 students with low levels of resilience in intervention group. Finally, 84 adolescents provided data at each assessment. At the same time, we selected 90 students in the control group. Paired sample t-test was used to compare every factor defined above by time. The result showed that mindfulness training increased students' resilience and emotional intelligence in experiment group. Then in the experiment group, latent growth modeling was used to (1) examine initial levels and changes in resilience over time and (2) predict initial levels and growth in resilience based on emotional intelligence. The findings of this study are as follows: during a mindfulness training intervention, (1) individual resilience tends to increase, and rate of increase grows gradually; there are also significant individual differences in the initial level and development speed; (2) individual emotional intelligence can promote the growth of resilience. With the worldwide outbreak of COVID-19, more and more attention is paid to the mental health of students. The research in this article shows that mindfulness training program should be given increasing consideration in the future.

Estimating the prevalence of stress among Indian students during the COVID-19 pandemic: A cross-sectional study from India

OBJECTIVE

Since December 2019, the COVID-19 pandemic has posed a substantial threat with its associated high mortality, infection, and risk of psychological stress. A large number of students are affected because of a prolonged break from academic activities and staying at home. The focus of this study is to understand the stress levels of Indian students, any psychological imbalances, and their major hurdles during the COVID-19 lockdown.

METHODS

Using a snowball sampling method, an online survey of the Perceived Stress Scale (PSS) was conducted on students across India. Along with their demographic details, the participants also reported their study patterns and challenges during their confinement period. The statistical scores for the responses were calculated and the demographic variables analysed. The levels indicated by the PSS were compared, and variance and regression analyses were performed.

RESULTS

We observed that students were generally stressed during lockdown and the pandemic. Females (mean = 3.03) were more stressed than males (mean = 2.61) as they were constantly under pressure because of stressful life events (OR = 0.752, 95% CI = 2.425-310.642) and apprehensive about their studies (RII = 0.67, OR = 2.168, 95% CI = 0.332-6.691).

CONCLUSION

During the pandemic, students' mental health needs to be continually monitored as they are stressed owing to fear as well as about their studies and future careers.

[Analysis of Changes and Factors Influencing Air Pollutants in the Beijing-Tianjin-Hebei Region During the COVID-19 Pandemic]

A series of strict control measures were imposed in the Beijing-Tianjin-Hebei region in early 2020 to control the spread of COVID-19. These measures have led to a reduction of anthropogenic air pollutants, providing an opportunity to observe the contribution of human activities to local air pollution. In this study, the control period was divided into four stages:the before, early, middle, and later stages. Based on a variety of data including meteorological, traffic, and industrial manufacturing datasets, statistical methods were combined with spatial analysis to evaluate changes in air pollution and associated human impacts during each stage. In addition, suggestions are made for further regional air pollution control in the Beijing-Tianjin-Hebei area. Key results are as follows:① Overall, the AQI and the concentrations of six air pollutants, especially SO₂, PM₁₀, and NO₂, were lower during control period than during the equivalent period in 2019 (reductions of 26.5%, 24.3%, and 16.9%, respectively). From the before to later stages, pollutants (except O₃) showed a downward trend while O₃ increased significantly during the before stage (by 76.2%) and the growth rate slowed during the middle and later stages; ②During the prior stage, Beijing experienced two periods with heavy air pollution days as a result of the local accumulation of pollutants, secondary transformation, and regional transport. The concentration of PM_2.5 in February was nearly 60% lower than in February 2014 under similar meteorological conditions in Beijing; ③ Following an increase in traffic volume and industrial activity, changes in air pollutants tended to be stable or slightly increase during the middle and later stages of the control period. The grey relation coefficients between thermal radiation intensity anomalies and the main pollutants in heavy industrial cities were greater than 0.6, which means that the control of industrial emissions remains key to controlling air pollution.