Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 32
Filter
1.
SSRN; 2022.
Preprint in English | SSRN | ID: ppcovidwho-333445

ABSTRACT

The COVID-19 pandemic has created a boom for online fitness service. While people may attribute this to the lockdown and social restriction policies, psychology literature suggests that people could simply be exercising more to cope with the stress induced by the pandemic. In this article, we test this hypothesis by examining users’ online yoga exercise before and after the pandemic outbreak. We find that the pandemic indeed led to a discontinuous surge in exercising hours, after controlling for the lockdown and restriction policies during the pandemic. This surge is also sustainable over time. In addition, users positively react to real-time pandemic variation by adjusting their activity levels. Together, the pandemic effects account for more than one-third of the observed activities on average. In addition to exercise activity, users show behavior adjustments in social interactions and spending, which is consistent with the literature on stress.

2.
Annals of the American Association of Geographers ; : 1-17, 2022.
Article in English | Taylor & Francis | ID: covidwho-1774302
3.
Am J Orthod Dentofacial Orthop ; 2022 Mar 17.
Article in English | MEDLINE | ID: covidwho-1748312

ABSTRACT

INTRODUCTION: Orthodontic students need to accurately identify cephalometric landmarks to perform cephalometric measurements, which is the prerequisite to proper orthodontic diagnosis and treatment. To provide insights into future cephalometric education, we compared the performance of different methods that can be used in tracing practice, including a novel online game-based method, the cephalometric training module of Uceph (version 948; Uceph, Chengdu, China). METHODS: A total of 45 first-year orthodontic graduate students were divided into 3 groups to receive different kinds of cephalometric training (module group, practicing with the cephalometric training module of Uceph; teaching group, practicing under the teacher's guidance; self-training group, practicing with traced cephalogram as reference). After training with 4 cephalograms, students completed 2 test samples in which the tracing accuracy and time were recorded and a questionnaire concerning their feelings. RESULTS: Both the teaching and module group offered performance advantages on increasing the tracing accuracy and speed of students. The module group provided a better performance on improving tracing accuracy than the teaching group. Students in the module group showed improved concentration, interest, satisfaction toward the teaching method and confidence of correctly identifying landmarks than self-training group, and enhanced interest than students in the teaching group. CONCLUSIONS: The shooting game-based cephalometric training module of Uceph has demonstrated better performance than traditional face-to-face teaching and self-learning, proving to be a viable online tool to train cephalometric tracing, especially during the coronavirus disease 2019 pandemic.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-325423

ABSTRACT

Previous studies have been focused primarily on modelling and predicting the transmission of COVID-19. While little research has been conducted to understand the impacts of different travel modes on the transmission of COVID-19, without an explicit understanding of the travel mode effects, many people intuitively perceive non-motorized travel modes to be safer than public transit as passengers in public transit are confined to small, enclosed spaces where the virus can transmit more easily. During the period when urban mobility gradually returns towards what was called ‘normal’ and transit systems and urban facilities reopen, new waves of the pandemic might be generated as travel mode choices significantly differ across cities and different travel behaviors are associated with diverse infectious sources. Thus, the current study focuses on understanding the impact of different travel modes on the transmission of COVID-19 in the long-term and at world-wide scales, aspects that have not received much attention in the research literature. Accordingly, a multivariate time series analysis has been developed to examine the impacts of daily confirmed cases and travel modes, based on driving, public transit, and walking as recorded in the Apple Mobility Trends Reports on COVID-19 transmission risks in 71 cities throughout the world from January to November 2020. The impact of population density in built-up areas and the degree to which the `wearing' of facemasks affects infections are also investigated. Among the three travel modes we examine, driving is the safest way to commute because drivers are physically separate from crowds. Unexpectedly, walking has a relatively low risk when the population density in built-up areas is high, which suggests that, globally, people have increased awareness of pandemic prevention. Although the general public is more worried about using public transit, this mode can still be safe in many large cities, a factor that is vital for informing policy making and developing trust among citizens so they will continue to commute using public transit when strict preventative measures are in place. From another perspective, infectious sources make the largest contribution to daily confirmed cases, thus demonstrating the importance of strict quarantine measures to block the source of infection. The results and conclusions presented herein are based on an analysis of spatio-temporal data that helps inform policy making and enable cities to be kept open when controlling the pandemic, which has become an urgent task for the international community when rebuilding the economy.

5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-315319

ABSTRACT

Background: Coronavirus disease 2019 (COVID-19) is an emerging global medical challenge and glucocorticoids remain the most promising therapy. Osteonecrosis (ON) is a disease caused by reduced blood flow to bones in the joints, which will rapidly induce joint destroy. ON had been frequently identified among convalescent patients after Severe Acute Respiratory Syndrome (SARS). Considering the similarity of SARS and COVID-19 on their pathogen, clinical characteristics and therapeutic strategies, it is particularly worrying whether ON will be a common sequela among convalescent COVID-19 patient.Methods: This multi-strategy study integrating different research methods, such as meta-analysis, systematic review and cross-sectional investigation. At first, two meta-analyses were performed on the incidence of osteonecrosis among SARS patients and the clinical data of glucocorticoid exposure among COVID-19 patients. Then, a systematic review of low-dosage glucocorticoid associated osteonecrosis and a real-world cross-sectional investigation of glucocorticoid exposure of COVID-19 patients in China Wuhan were also provided. Moreover, the pathogenesis, diagnosis, prevention, and treatment options for osteonecrosis after COVID-19 infection were further described.Findings: Our meta-analysis showed that 32% of SARS patients had developed ON after receiving glucocorticoid treatment with high dose, and our system review also supported that low level glucocorticoid exposure may lead to the occurrence of ON. Similarly, 40% of COVID-19 patients had undergone glucocorticoid treatment according to our meta-analysis. The cross-sectional investigation in China Wuhan found that the average of cumulative glucocorticoid exposure level was 504 mg calculated by the dosage of methylprednisolone. Notably, a confirmed osteonecrosis case after COVID-19 was identified during our investigation. Preventive management of ON shall better start with regular clinical followup observation.Interpretation: Growing evidence of the glucocorticoid therapy for COVID-19 patients prompts us to put forward the risk-classification-based early screening and early prevention protocol of ON, which may be of clinical significance in favorable prognosis of this disease.Registration Details: PROSPERO, registration number CRD42020203536.Funding Information: This study was supported by the Special Project For COVID-19 Prevention and Management of Ministry of Education of China (2020-JYB-YJ-023), the National Key Research and Development Program of China (2019ZX09731-002) and the State Key Program of National Natural Science Foundation of China (82030122).Declaration of Interests: The authors declare no competing interests.Ethics Approval Statement: The protocol for the investigation study has been registered in the Chinese Clinical Trial Registry (ChiCTR), (URL: http://www.chictr.org.cn/showproj.aspx?proj=61769, No. ChiCTR2000038333). This study was approved by the Ethics Institutional Review Board of the Third Affiliated Hospital of Beijing University of Chinese Medicine (No. BZYSY-2020KYKTPJ-06), and informed consent was obtained from every participant patient.

6.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-314580

ABSTRACT

Background: In December 2019, the first case of pneumonia associated with the SARS-CoV-2 was found in Wuhan and rapidly spread throughout China, so data are needed on the affected patients. The purpose of our study was to find the clinical manifestations and CT features of COVID-19.Methods All patients with COVID-19 in Taizhou city were retrospectively included and divided into non-severe group and severe group according to the severity of the disease. The clinical manifestations, laboratory examinations and imaging features of COVID-19 patients were analyzed, and the differences between the two groups were compared.Results A total of 143 laboratory-confirmed cases were included in the study, including 110 non-severe patients and 33 severe patients. The median age of patients was 47 (range 4–86 years). Fever (73.4%) and cough (63.6%) were the most common initial clinical symptoms. Between two groups of cases, the results of aspartate transaminase, creatine kinase and lactate dehydrogenase, serum albumin, CPR, glomerular filtration rate, amyloid protein A, fibrinogen, calcitonin level and oxygen partial pressure, red protein, IL – 10, absolute value of CD3, CD4, CD8 were different, and the difference was statistically significant (P < 0.05). On admission, the CT showed that the lesions were mostly distributed in the external lung or under the pleura (135 cases (98%)), and most of lesions presented as patchy (81%), heterogeneous (73%) and mixed density (63%) shadow. Consolidation (68% vs 41%), bronchial inflation signs (59% vs 41%), and bronchiectasis (71% vs 39%) were more common in the severe group.Conclusions Most of the cases of COVID-19 in Taizhou have mild symptoms and no death. In addition to clinical symptoms, some laboratory tests (such as absolute values of CD4 and CD8) and CT findings can be used to assess the severity of the disease.

7.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-314579

ABSTRACT

Background: The outbreak of COVID-19 has a significant impact on the health of people around the world. In the clinical condition of COVID-19, the condition of critical cases changes rapidly with a high mortality rate. Therefore, early prediction of disease severity and active intervention play an important role in the prognosis of severe patients. Methods: All the patients with COVID-19 in Taizhou city were retrospectively included and segregated into the non-severe and severe group according to the severity of the disease. The clinical manifestations, laboratory examination results, and imaging findings of the 2 groups were analysed for comparing the differences between the 2 groups. Univariate and multivariate logistic regression were used for screening the factors that could predict the disease, and the nomogram was constructed. Results: : A total of 143 laboratory-confirmed cases were included in the study, including 110 non-severe patients and 33 severe patients. The median age of patients was 47 years (range, 4–86 years). Fever (73.4%) and cough (63.6%) were the most common initial clinical symptoms. By using the method of multivariate logistic regression, the variables to construct nomogram include age (OR: 1.052, 95% CI: 1.020–1.086, P = 0.001), body temperature (OR: 2.252, 95% CI: 1.139–4.450, P = 0.020), lymphocyte count (OR: 1.128, 95% CI: 1.000–1.272, P = 0.049), ADA (OR: 1.163, 95% CI: 1.023–1.323, P = 0.021), PaO 2 (OR: 0.972, 95% CI: 0.953–0.992, P = 0.007), IL-10 (OR: 1.184, 95% CI: 1.037–1.351, P = 0.012), and bronchiectasis (OR: 3.818, 95% CI: 1.694–8.605, P = 0.001). The AUC of the established nomogram was 0.877. Conclusions: : This study established a stable nomogram for predicting the severity of COVID-19, and the clinicians can use the established nomogram for predicting the severity of newly diagnosed COVID-19 patients and to conduct active intervention for minimising the mortality rate and improving the prognosis of severe patients.

8.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-308196

ABSTRACT

Tropospheric nitrogen dioxide (NO$_2$) concentrations are strongly affected by anthropogenic activities. Using space-based measurements of tropospheric NO$_2$, here we investigate the responses of tropospheric NO$_2$ to the 2019 novel coronavirus (COVID-19) over China, South Korea, and Italy. We find noticeable reductions of tropospheric NO$_2$ columns due to the COVID-19 controls by more than 40% over E. China, South Korea, and N. Italy. The 40% reductions of tropospheric NO$_2$ are coincident with intensive lockdown events as well as up to 20% reductions in anthropogenic nitrogen oxides (NO$_x$) emissions. The perturbations in tropospheric NO$_2$ diminished accompanied with the mitigation of COVID-19 pandemic, and finally disappeared within around 50-70 days after the starts of control measures over all three nations, providing indications for the start, maximum, and mitigation of intensive controls. This work exhibits significant influences of lockdown measures on atmospheric environment, highlighting the importance of satellite observations to monitor anthropogenic activity changes.

9.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-310725

ABSTRACT

Background: In December 2019, COVID-19 emerged in Wuhan, China. By 8 July 2020, the cumulative number of infected people worldwide had exceeded 11.50 million. It has been reported that a variety of indicators, including lymphocytes, can predict the progression of COVID-19 disease, but the clinical application value of eosinophils has not received widespread attention. It’s specific changes in the course of the disease, as well as the relationship with severity and prognosis of COVID-19 patients, need to be further studied.Method: In this multicenter, retrospective study, we collected data on laboratory-confirmed 482 COVID-19 patients from three hospitals in Wuhan, China, who died or were discharged between February 1, 2020, and February 20, 2020. By collecting the clinical data and laboratory examination results of the patients, we analyzed the changes of eosinophil and lymphocyte count in patients with different severity and outcomes, so as to study their relationship with the severity and prognosis, to compare the diagnostic effects of lymphocytes and eosinophils on severe COVID-2019 patients.Result: A total of 482 patients were enrolled in this study. Of those, 39.0% were severe patients and 13.3% were nonsurvivors. All the nonsurvivors were from the severe group. The count of eosinophil remained relatively lower levels during hospitalization in the severe and nonsurvival groups compared with the nonsevere and survival groups (all P < 0.05). Patients with the lowest eosinophil count during hospitalization reduced to <0.02×10⁹/L and =0.00×10⁹/L had higher rates of severity and fatality (all P < 0.05). The lowest counts of lymphocyte and eosinophil during hospitalization were used to analyze the diagnostic efficacy of severe COVID-19, and their diagnostic effects were similar. The cutoff values were ≤0.72×10⁹/L and =0.00×10⁹/L, and the areas under the curve were 0.768 and 0.740, respectively. Multivariate Cox regression model showed that the older age, the emergence of dyspnea, the increase of the white blood cell count on admission, the decrease of lymphocyte count on admission, and eosinophil count reduced to =0.00×10⁹/L on admission were associated with fatal outcome.Conclusion: Eosinophil and lymphocyte count remained relatively lower levels during hospitalization in the severe and nonsurvival COVID-19 patients, and patients with eosinophil decline had higher rates of severity and fatality. Eosinophils = 0.00×10⁹/L and lymphocytes ≤0.72×10⁹/L had the similar efficacy to diagnosis the severe COVID-19 patients. Compared with lymphocytes, eosinophils could also be used to diagnose severe COVID-19 patients and predict prognosis.Funding Statement: This study is funded by grants from the Natural Science Foundation of China (81974383 and 81772607 to W.Y.;81770554 and 81570501 to Y.F.)Declaration of Interests: None.Ethics Approval Statement: The study was approved by the Ethics Commission of Wuhan Tongji Hospital, Union Hospital, and Jin Yin-tan Hospital, and written informed consent was waived.

10.
Viruses ; 14(2)2022 01 19.
Article in English | MEDLINE | ID: covidwho-1625933

ABSTRACT

The COVID-19 epidemic is raging around the world. Neutralizing antibodies are powerful tools for the prevention and treatment of SARS-CoV-2 infection. Antibody CR3022, a SARS-CoV neutralizing antibody, was found to cross-react with SARS-CoV-2, but its affinity was lower than that of its binding with SARS-CoV, which greatly limited the further development of CR3022 against SARS-CoV-2. Therefore, it is necessary to improve its affinity to SARS-CoV-2 in vitro. In this study, the structure-based molecular simulations were utilized to virtually mutate the possible key residues in the complementarity-determining regions (CDRs) of the CR3022 antibody. According to the criteria of mutation energy, the mutation sites that have the potential to impact the antibody affinity were then selected. Then optimized CR3022 mutants with the enhanced affinity were further identified and verified by enzyme-linked immunosorbent assay (ELISA), surface plasma resonance (SPR) and autoimmune reactivity experiments. Finally, molecular dynamics (MD) simulation and binding free energy calculation (MM/PBSA) were performed on the wild-type CR3022 and its two double-site mutants to understand in more detail the contribution of these sites to the higher affinity. It was found that the binding affinity of the CR3022 antibody could be significantly enhanced more than ten times after the introduction of the S103F/Y mutation in HCDR-3 and the S33R mutation in LCDR-1. The additional hydrogen-bonding, hydrophobic interactions, as well as salt-bridges formed between the modified double-site mutated antibody and SARS-CoV-2 RBD were identified. The computational and experimental results clearly demonstrated that the affinity of the modified antibody has been greatly enhanced. This study indicates that CR3022 as a neutralizing antibody recognizing the conserved region of RBD against SARS-CoV with cross-reactivity with SARS-CoV-2, a different member in a large family of coronaviruses, could be improved by the computational and experimental approaches which provided insights for developing antibody drugs against SARS-CoV-2.


Subject(s)
Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/metabolism , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/metabolism , Antibody Affinity , Molecular Dynamics Simulation , SARS-CoV-2/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Cross Reactions , Protein Binding , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/immunology
12.
Wireless Communications & Mobile Computing (Online) ; 2021, 2021.
Article in English | ProQuest Central | ID: covidwho-1476887

ABSTRACT

Wearing masks is an effective and simple method to prevent the spread of the COVID-19 pandemic in public places, such as train stations, classrooms, and streets. It is of positive significance to urge people to wear masks with computer vision technology. However, the existing detection methods are mainly for simple scenes, and facial missing detection is prone to occur in dense crowds with different scales and occlusions. Moreover, the data obtained by surveillance cameras in public places are difficult to be collected for centralized training, due to the privacy of individuals. In order to solve these problems, a cascaded network is proposed: the first level is the Dilation RetinaNet Face Location (DRFL) Network, which contains Enhanced Receptive Field Context (ERFC) module with the dilation convolution, aiming to reduce network parameters and locate faces of different scales. In order to adapt to embedded camera devices, the second level is the SRNet20 network, which is created by Neural Architecture Search (NAS). Due to privacy protection, it is difficult for surveillance video to share in practice, so our SRNet20 network is trained in federated learning. Meanwhile, we have made a masked face dataset containing about 20,000 images. Finally, the experiments highlight that the detection mAP of the face location is 90.6% on the Wider Face dataset, and the classification mAP of the masked face classification is 98.5% on the dataset we made, which means our cascaded network can detect masked faces in dense crowd scenes well.

13.
Front Med (Lausanne) ; 8: 764493, 2021.
Article in English | MEDLINE | ID: covidwho-1450820

ABSTRACT

[This corrects the article DOI: 10.3389/fmed.2020.584342.].

14.
Int J Environ Res Public Health ; 18(14)2021 07 14.
Article in English | MEDLINE | ID: covidwho-1314641

ABSTRACT

With the COVID-19 vaccination widely implemented in most countries, propelled by the need to revive the tourism economy, there is a growing prospect for relieving the social distancing regulation and reopening borders in tourism-oriented countries and regions. This need incentivizes stakeholders to develop border control strategies that fully evaluate health risks if mandatory quarantines are lifted. In this study, we have employed a computational approach to investigate the contact tracing integrated policy in different border-reopening scenarios in Hong Kong, China. Explicitly, by reconstructing the COVID-19 transmission from historical data, specific scenarios with joint effects of digital contact tracing and other concurrent measures (i.e., controlling arrival population and community nonpharmacological interventions) are applied to forecast the future development of the pandemic. Built on a modified SEIR epidemic model with a 30% vaccination coverage, the results suggest that scenarios with digital contact tracing and quick isolation intervention can reduce the infectious population by 92.11% compared to those without contact tracing. By further restricting the inbound population with a 10,000 daily quota and applying moderate-to-strong community nonpharmacological interventions (NPIs), the average daily confirmed cases in the forecast period of 60 days can be well controlled at around 9 per day (95% CI: 7-12). Two main policy recommendations are drawn from the study. First, digital contact tracing would be an effective countermeasure for reducing local virus spread, especially when it is applied along with a moderate level of vaccination coverage. Second, implementing a daily quota on inbound travelers and restrictive community NPIs would further keep the local infection under control. This study offers scientific evidence and prospective guidance for developing and instituting plans to lift mandatory border control policies in preparing for the global economic recovery.


Subject(s)
COVID-19 , Quarantine , COVID-19 Vaccines , China , Contact Tracing , Hong Kong , Humans , Models, Theoretical , Policy , Prospective Studies , SARS-CoV-2
15.
Int J Environ Res Public Health ; 18(13)2021 06 26.
Article in English | MEDLINE | ID: covidwho-1288864

ABSTRACT

The impact of Coronavirus Disease 2019 (COVID-19) on cause-specific mortality has been investigated on a global scale. However, less is known about the excess all-cause mortality and air pollution-human activity responses. This study estimated the weekly excess all-cause mortality during COVID-19 and evaluated the impacts of air pollution and human activities on mortality variations during the 10th to 52nd weeks of 2020 among sixteen countries. A SARIMA model was adopted to estimate the mortality benchmark based on short-term mortality during 2015-2019 and calculate excess mortality. A quasi-likelihood Poisson-based GAM model was further applied for air pollution/human activity response evaluation, namely ground-level NO2 and PM2.5 and the visit frequencies of parks and workplaces. The findings showed that, compared with COVID-19 mortality (i.e., cause-specific mortality), excess all-cause mortality changed from -26.52% to 373.60% during the 10th to 52nd weeks across the sixteen countries examined, revealing higher excess all-cause mortality than COVID-19 mortality in most countries. For the impact of air pollution and human activities, the average country-level relative risk showed that one unit increase in weekly NO2, PM2.5, park visits and workplace visits was associated with approximately 1.54% increase and 0.19%, 0.23%, and 0.23% decrease in excess all-cause mortality, respectively. Moreover, compared with the impact on COVID-19 mortality, the relative risks of weekly NO2 and PM2.5 were lower, and the relative risks of weekly park and workplace visits were higher for excess all-cause mortality. These results suggest that the estimation based on excess all-cause mortality reduced the potential impact of air pollution and enhanced the influence of human activities compared with the estimation based on COVID-19 mortality.


Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Epidemics , Air Pollutants/analysis , Air Pollutants/toxicity , Air Pollution/adverse effects , Air Pollution/analysis , Environmental Exposure/analysis , Human Activities , Humans , Mortality , Particulate Matter/analysis , Particulate Matter/toxicity , SARS-CoV-2
16.
ISPRS International Journal of Geo-Information ; 10(6):401, 2021.
Article in English | MDPI | ID: covidwho-1264467

ABSTRACT

The novel coronavirus disease 2019 (COVID-19) has caused significantly changes in worldwide environmental and socioeconomics, especially in the early stage. Previous research has found that air pollution is potentially affected by these unprecedented changes and it affects COVID-19 infections. This study aims to explore the non-linear association between yearly and daily global air pollution and the confirmed cases of COVID-19. The concentrations of tropospheric air pollution (CO, NO2, O3, and SO2) and the daily confirmed cases between 23 January 2020 and 31 May 2020 were collected at the global scale. The yearly discrepancies of air pollutions and daily air pollution are associated with total and daily confirmed cases, respectively, based on the generalized additive model. We observed that there are significant spatially and temporally non-stationary variations between air pollution and confirmed cases of COVID-19. For the yearly assessment, the number of confirmed cases is associated with the positive fluctuation of CO, O3, and SO2 discrepancies, while the increasing NO2 discrepancies leads to the significant peak of confirmed cases variation. For the daily assessment, among the selected countries, positive linear or non-linear relationships are found between CO and SO2 concentrations and the daily confirmed cases, whereas NO2 concentrations are negatively correlated with the daily confirmed cases;variations in the ascending/declining associations are identified from the relationship of the O3-confirmed cases. The findings indicate that the non-linear relationships between global air pollution and the confirmed cases of COVID-19 are varied, which implicates the needs as well as the incorporation of our findings in the risk monitoring of public health on local, regional, and global scales.

17.
Sci Rep ; 11(1): 11908, 2021 06 07.
Article in English | MEDLINE | ID: covidwho-1260948

ABSTRACT

Urban functional fragmentation plays an important role in assessing Nitrogen Dioxide (NO2) emissions and variations. While the mediated impact of anthropogenic-emission restriction has not been comprehensively discussed, the lockdown response to the novel coronavirus disease 2019 (COVID-19) provides an unprecedented opportunity to meet this goal. This study proposes a new idea to explore the effects of urban functional fragmentation on NO2 variation with anthropogenic-emission restriction in China. First, NO2 variations are quantified by an Autoregressive Integrated Moving Average with external variables-Dynamic Time Warping (SARIMAX-DTW)-based model. Then, urban functional fragmentation indices including industrial/public Edge Density (ED) and Landscape Shape Index (LSI), urban functional Aggregation Index (AI) and Number of Patches (NP) are developed. Finally, the mediated impacts of anthropogenic-emission restriction are assessed by evaluating the fragmentation-NO2 variation association before and during the lockdown during COVID-19. The findings reveal negative effects of industrial ED, public LSI, urban functional AI and NP and positive effects of public ED and industrial LSI on NO2 variation based on the restricted anthropogenic emissions. By comparing the association analysis before and during lockdown, the mediated impact of anthropogenic-emission restriction is revealed to partially increase the effect of industrial ED, industrial LSI, public LSI, urban functional AI and NP and decrease the effect of public ED on NO2 variation. This study provides scientific findings for redesigning the urban environment in related to the urban functional configuration to mitigating the air pollution, ultimately developing sustainable societies.

18.
Journalism ; : 14648849211023153, 2021.
Article in English | Sage | ID: covidwho-1259137

ABSTRACT

Social media has become a channel through which journalists distribute their work, reach audiences and gain visibility. Informed by the frameworks of journalistic branding, the heuristic-systematic model, and hypertextual elements, the present study examines the extent to which the source factor (journalists? branding on social media profiles) and message factors (communication styles and hypertextual elements) influence visibility (i.e. the popularity of the account and the number of favourites and retweets of the posts). We analysed the Twitter profiles of 98 health journalists from seven major media organizations in the US and conducted a manual content analysis of a representative sample of their public tweets (n?=?3982) published during the Covid-19 pandemic. In contrast to expectations, branding contributed little to any indicators of visibility, and profiles with institutional branding had fewer followers. Both affective messages and rational messages received more likes and retweets than messages without these elements. Tweets containing images or news-related hyperlinks received more retweets, whereas the number of @mentions in a tweet was negatively related to visibility. Journalists from traditional media, those who tweeted more often, and those with more followers had higher levels of visibility.

19.
Environmental Research Letters ; 16(5), 2021.
Article in English | ProQuest Central | ID: covidwho-1223300

ABSTRACT

The massive lockdown of global cities during the COVID-19 pandemic is substantially improving the atmospheric environment, which for the first time, urban mobility is virtually reduced to zero, and it is then possible to establish a baseline for air quality. By comparing these values with pre-COVID-19 data, it is possible to infer the likely effect of urban mobility and spatial configuration on the air quality. In the present study, a time-series prediction model is enhanced to estimate the nationwide NO2 concentrations before and during the lockdown measures in the United States, and 54 cities are included in the study. The prediction generates a notable NO2 difference between the observations if the lockdown is not considered, and the changes in urban mobility can explain the difference. It is found that the changes in urban mobility associated with various road textures have a significant impact on NO2 dispersion in different types of climates.

20.
ISPRS International Journal of Geo-Information ; 10(3):123, 2021.
Article in English | Academic Search Complete | ID: covidwho-1161082

ABSTRACT

The novel coronavirus disease (COVID-19) has become a public health problem at a global scale because of its high infection and mortality rate. It has affected most countries in the world, and the number of confirmed cases and death toll is still growing rapidly. Susceptibility studies have been conducted in specific countries, where COVID-19 infection and mortality rates were highly related to demographics and air pollution, especially PM2.5, but there are few studies on a global scale. This paper is an exploratory study of the relationship between confirmed COVID-19 cases and death toll per million population, population density, and PM2.5 concentration on a worldwide basis. A multivariate linear regression based on Moran eigenvector spatial filtering model and Geographically weighted regression model were undertaken to analyze the relationship between population density, PM2.5 concentration, and COVID-19 infection and mortality rate, and a geostatistical method with bivariate local spatial association analysis was adopted to explore their spatial correlations. The results show that there is a statistically significant positive relationship between COVID-19 confirmed cases and death toll per million population, population density, and PM2.5 concentration, but the relationship displays obvious spatial heterogeneity. While some adjacent countries are likely to have similar characteristics, it suggests that the countries with close contacts/sharing borders and similar spatial pattern of population density and PM2.5 concentration tend to have similar patterns of COVID-19 risk. The analysis provides an interpretation of the statistical and spatial association of COVID-19 with population density and PM2.5 concentration, which has implications for the control and abatement of COVID-19 in terms of both infection and mortality. [ABSTRACT FROM AUTHOR] Copyright of ISPRS International Journal of Geo-Information is the property of MDPI Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

SELECTION OF CITATIONS
SEARCH DETAIL