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1.
Xxiv Isprs Congress Imaging Today, Foreseeing Tomorrow, Commission Iv ; 43-B4:79-84, 2022.
Article in English | Web of Science | ID: covidwho-2072065

ABSTRACT

At the beginning of the COVID-19 pandemic, most scholars focused on how international transportation (such as airlines) spread the virus to different countries. At this point, scholars have begun to pay more attentions on how COVID-19 locally transmission via ground transportation systems. Because many people use these ground services to commute in urban areas, a high passenger volume may lead to a domestic large outbreak. Without detailed disease spreading path, healthcare professionals are still not sure where and how to apply these anti-epidemic measures. Therefore, this study chose the Taipei metro system as our study area to investigate the relationship between metro station passenger volume and COVID-19 transmission. By using the electric metro ticket data, we know the movement of metro passengers in Taipei, and this OD movement dataset was used to estimate the spreading path of the COVID-19. In order to simulate possible Covid-19 spreading cases in the real world, two different methods (the agent-based model (a micro-level simulation) and the effective distance method (a macro-level estimator)) were applied. Then, we compared the COVID -19 arrival order for each station. In our result, the average infectious order of stations of agent based model and shortest path effective distance is similar. Among all stations, Taipei Main Station is the first infectious station, and the top 15 infectious stations are similar according to result of the two method. Our result may help the authority choose proper methods to simulate the epidemic local transmission and then allocate resources effectively in the future.

2.
Journal of Food and Drug Analysis ; 30(2):252-270, 2022.
Article in English | Web of Science | ID: covidwho-1918368

ABSTRACT

On analyzing the results of cell-based assays, we have previously shown that perilla (Perilla frutescens) leaf extract (PLE), a food supplement and orally deliverable traditional Chinese medicine approved by the Taiwan Food and Drug Administration, effectively inhibits SARS-CoV-2 by directly targeting virions. PLE was also found to modulate virus-induced cytokine expression levels. In this study, we explored the anti-SARS-CoV-2 activity of PLE in a hamster model by examining viral loads and virus-induced immunopathology in lung tissues. Experimental animals were intranasally challenged with different SARS-CoV-2 doses. Jugular blood samples and lung tissue specimens were obtained in the acute disease stage (3-4 post-infection days). As expected, SARS-CoV-2 induced lung inflammation and hemorrhagic effusions in the alveoli and perivascular areas;additionally, it increased the expression of several immune markers of lung injury - including lung Ki67-positive cells, Iba-1-positive macrophages, and myeloperoxidase-positive neutrophils. Virus-induced lung alterations were significantly attenuated by orally administered PLE. In addition, pretreatment of hamsters with PLE significantly reduced viral loads and immune marker expression. A purified active fraction of PLE was found to confer higher antiviral protection. Notably, PLE prevented SARS-CoV-2-induced increase in serum markers of liver and kidney function as well as the decrease in serum high-density lipoprotein and total cholesterol levels in a dose-dependent fashion. Differently from lung pathology, monitoring of serum biomarkers in Syrian hamsters may allow a more humane assessment of the novel drugs with potential anti-SARS-CoV-2 activity. Our results expand prior research by confirming that PLE may exert an in vivo therapeutic activity against SARS-CoV-2 by attenuating viral loads and lung tissue inflammation, which may pave the way for future clinical applications.

3.
16th Annual IEEE International Systems Conference, SysCon 2022 ; 2022.
Article in English | Scopus | ID: covidwho-1874341

ABSTRACT

The COVID-19 pandemic has had a major impact on the usage of various utilities. To assess the impact, this research explores the (baseline) estimation of hourly utility usage if the pandemic did not happen. Using usage data from Harris SmartWorks, various machine learning algorithms are implemented to show that they are effective in modelling hourly usage patterns, calendar effects, as well as 'lingering' effects of the exogenous factors and produce accurate results. © 2022 IEEE.

4.
Journal of Electronic Commerce Research ; 23(2):115-137, 2022.
Article in English | Scopus | ID: covidwho-1843208

ABSTRACT

Social commerce has been seeing exponential growth due to the COVID-19 pandemic, which brought a wave of cross-border commerce as consumers purchase more items online. Business uses social media to reach new markets by accessing potential global buyers, expanding their target markets, and increasing brand popularity. Cross-border ecommerce studies showed that perceived risk is a critical factor that reduces individuals’ willingness to purchase unfamiliar foreign products. We introduced an emerging business model, cross-border social commerce (CBSC) and examined the mitigation of perceived risk through trust transfer in a CBSC context. To capture consumers’ purchase intention of cross-border commerce, we conducted an online scenario-based survey. Survey respondents comprising a total of 321 social media users in Indonesia were observed. The results demonstrate that consumers’ trust can be transferred from friends and platforms to brands, and the transfer effect is contingent on the popularity of the brand. Our findings have crucial implications for trust transfer and cross-border social commerce. This study contributes to academia by introducing a new business model and advancing our understanding of how to enhance trust and mitigate risk. Practitioners can gain insight into trust building in CBSC context. © 2022. Journal of Electronic Commerce Research. All Rights Reserved.

5.
PubMed; 2020.
Preprint in English | PubMed | ID: ppcovidwho-333553

ABSTRACT

BACKGROUND: The absence of systematic surveillance for SARS-CoV-2 has curtailed accurate appraisal of transmission intensity. Our objective was to perform case detection of an entire rural community to quantify SARS-CoV-2 transmission using PCR and antibody testing. METHODS: We conducted a cross-sectional survey of the prevalence and cumulative incidence of SARS-CoV-2 infection in the rural town of Bolinas, California (population 1,620), four weeks following shelter-in-place orders. Residents and county essential workers were tested between April 20th-24th, 2020. Prevalence by PCR and seroprevalence combining data from two forms of antibody testing were performed in parallel (Abbott ARCHITECT IgG to nucleocapsid protein and in-house IgG ELISA to the receptor binding domain). RESULTS: Of 1,891 participants, 1,312 were confirmed Bolinas residents (>80% community ascertainment). Zero participants were PCR positive. Assuming 80% sensitivity, it would have been unlikely to observe these results (p<0.05) if there were >3 active infections in the community. Based on antibody results, estimated prevalence of prior infection was 0.16% (95% CrI: 0.02%, 0.46%). Seroprevalence estimates using only one of the two tests would have been higher, with greater uncertainty. The positive predictive value (PPV) of a positive result on both tests was 99.11% (95% CrI: 95.75%, 99.94%), compared to PPV 44.19%-63.32% (95% CrI range 3.25%-98.64%) if only one test was utilized. CONCLUSIONS: Four weeks following shelter-in-place, active and prior SARS-CoV-2 infection in a rural Northern California community was extremely rare. In this low prevalence setting, use of two antibody tests increased the PPV and precision of seroprevalence estimates.

6.
PubMed; 2020.
Preprint in English | PubMed | ID: ppcovidwho-333508

ABSTRACT

BACKGROUND: Serological tests are crucial tools for assessments of SARS-CoV-2 exposure, infection and potential immunity. Their appropriate use and interpretation require accurate assay performance data. METHOD: We conducted an evaluation of 10 lateral flow assays (LFAs) and two ELISAs to detect anti-SARS-CoV-2 antibodies. The specimen set comprised 128 plasma or serum samples from 79 symptomatic SARS-CoV-2 RT-PCR-positive individuals;108 pre-COVID-19 negative controls;and 52 recent samples from individuals who underwent respiratory viral testing but were not diagnosed with Coronavirus Disease 2019 (COVID-19). Samples were blinded and LFA results were interpreted by two independent readers, using a standardized intensity scoring system. RESULTS: Among specimens from SARS-CoV-2 RT-PCR-positive individuals, the percent seropositive increased with time interval, peaking at 81.8-100.0% in samples taken >20 days after symptom onset. Test specificity ranged from 84.3-100.0% in pre-COVID-19 specimens. Specificity was higher when weak LFA bands were considered negative, but this decreased sensitivity. IgM detection was more variable than IgG, and detection was highest when IgM and IgG results were combined. Agreement between ELISAs and LFAs ranged from 75.7-94.8%. No consistent cross-reactivity was observed. CONCLUSION: Our evaluation showed heterogeneous assay performance. Reader training is key to reliable LFA performance, and can be tailored for survey goals. Informed use of serology will require evaluations covering the full spectrum of SARS-CoV-2 infections, from asymptomatic and mild infection to severe disease, and later convalescence. Well-designed studies to elucidate the mechanisms and serological correlates of protective immunity will be crucial to guide rational clinical and public health policies.

7.
Anesthesia and Analgesia ; 132(5S_SUPPL):374-374, 2021.
Article in English | Web of Science | ID: covidwho-1696184
8.
MEDLINE;
Preprint in English | MEDLINE | ID: ppcovidwho-326681

ABSTRACT

As novel SARS-CoV-2 variants continue to emerge, it is critical that their potential to cause severe disease and evade vaccine-induced immunity is rapidly assessed in humans and studied in animal models. In early January 2021, a novel variant of concern (VOC) designated B.1.429 comprising 2 lineages, B.1.427 and B.1.429, was originally detected in California (CA) and shown to enhance infectivity in vitro and decrease antibody neutralization by plasma from convalescent patients and vaccine recipients. Here we examine the virulence, transmissibility, and susceptibility to pre-existing immunity for B 1.427 and B 1.429 in the Syrian hamster model. We find that both strains exhibit enhanced virulence as measured by increased body weight loss compared to hamsters infected with ancestral B.1 (614G), with B.1.429 causing the most body weight loss among all 3 lineages. Faster dissemination from airways to parenchyma and more severe lung pathology at both early and late stages were also observed with B.1.429 infections relative to B.1. (614G) and B.1.427 infections. In addition, subgenomic viral RNA (sgRNA) levels were highest in oral swabs of hamsters infected with B.1.429, however sgRNA levels in lungs were similar in all three strains. This demonstrates that B.1.429 replicates to higher levels than ancestral B.1 (614G) or B.1.427 in the upper respiratory tract (URT) but not in the lungs. In multi-virus in-vivo competition experiments, we found that epsilon (B.1.427/B.1.429) and gamma (P.1) dramatically outcompete alpha (B.1.1.7), beta (B.1.351) and zeta (P.2) in the lungs. In the URT gamma, and epsilon dominate, but the highly infectious alpha variant also maintains a moderate size niche. We did not observe significant differences in airborne transmission efficiency among the B.1.427, B.1.429 and ancestral B.1 (614G) variants in hamsters. These results demonstrate enhanced virulence and high relative fitness of the epsilon (B.1.427/B.1.429) variant in Syrian hamsters compared to an ancestral B.1 (614G) strain. Author Summary: In the last 12 months new variants of SARS-CoV-2 have arisen in the UK, South Africa, Brazil, India, and California. New SARS-CoV-2 variants will continue to emerge for the foreseeable future in the human population and the potential for these new variants to produce severe disease and evade vaccines needs to be understood. In this study, we used the hamster model to determine the epsilon (B.1.427/429) SARS-CoV-2 strains that emerged in California in late 2020 cause more severe disease and infected hamsters have higher viral loads in the upper respiratory tract compared to the prior B.1 (614G) strain. These findings are consistent with human clinical data and help explain the emergence and rapid spread of this strain in early 2021.

9.
PubMed; 2020.
Preprint in English | PubMed | ID: ppcovidwho-296875

ABSTRACT

We report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seropositivity was 0.26% in 387 hospitalized patients admitted for non-respiratory indications and 0.1% in 1,000 blood donors. We additionally describe the longitudinal dynamics of immunoglobulin-G, immunoglobulin-M, and in vitro neutralizing antibody titers in COVID-19 patients. Neutralizing antibodies rise in tandem with immunoglobulin levels following symptom onset, exhibiting median time to seroconversion within one day of each other, and there is >93% positive percent agreement between detection of immunoglobulin-G and neutralizing titers.

10.
New Normal and New Rules in International Trade, Economics and Marketing ; : 1-424, 2021.
Article in English | Scopus | ID: covidwho-1574125

ABSTRACT

The coronavirus epidemic, which swept the whole world at the beginning of 2020 and turned into a widespread pandemic, has caused an important economic and social crisis. Governments and policy makers have tried to keep business life afloat with financial incentives and supports, government aids to combat the epidemic. The habits of doing business with remote working, flexible working, social media and internet use and online systems have been heavily used. After the Great Depression, the COVID epidemic caused serious contraction on the global economy. Therefore, it is important to examine the effects of this crisis by experts. With this book, the effects of the COVID crisis on different fields have been examined in detail by experts from different disciplines. We hope that this book will make significant contributions to researchers and scientists. © Peter Lang GmbH Internationaler Verlag der Wissenschaften Berlin 2021. All rights reserved.

11.
New Normal and New Rules in International Trade, Economics and Marketing ; : 231-252, 2021.
Article in English | Scopus | ID: covidwho-1573411

ABSTRACT

This chapter aims to study female consumers' perceptions of buying cosmetic products during the COVID- 19 pandemic in terms of specific discount strategies. Different types of discount patterns have a positive relationship with perceived price attractiveness and purchase intention. The results show that the most effective way to motivate Chinese customers to purchase cosmetics during the epidemic is the price discount. Therefore, this study will help the cosmetic industry better understand consumers' perception and shopping behaviors towards cosmetics, especially when all people are in lockdown and must wear masks on many occasions and in public areas. Simultaneously, it can be a reference for cosmetic companies to study and better grasp consumer consumption behavior changes during a crisis. © Peter Lang GmbH Internationaler Verlag der Wissenschaften Berlin 2021. All rights reserved.

12.
New England Journal of Medicine ; 385(18):1728-1728, 2021.
Article in English | Web of Science | ID: covidwho-1507481
13.
Oxford Bulletin of Economics and Statistics ; : 21, 2021.
Article in English | Web of Science | ID: covidwho-1494819

ABSTRACT

We develop a daily composite index of financial stress for the United Kingdom over 50 years, the UKFSI. The index includes market stress indicators based on their incremental information to capture financial crises. During the COVID-19 crisis, financial stress peaks but remains less severe than during the Global Financial Crisis. The UKFSI is used in a threshold vector autoregression to differentiate the economic dynamics between tranquil and stressful periods. We highlight the importance of nonlinearities that amplify shocks. But we find no evidence of financial shocks contributing to the COVID-19 crisis, possibly reflecting effective policy interventions.

14.
Journal of Pacific Rim Psychology ; 15, 2021.
Article in English | Scopus | ID: covidwho-1354717

ABSTRACT

Many COVID-19 conspiracy theories implicate China and its agents, whether implicitly or explicitly, as conspirators with potentially malicious intent behind the current pandemic. We set out to explore whether Chinese people believe in pandemic-related conspiracy theories, and if so, how do their secure (in-group identification) and defensive (collective narcissism) in-group positivity predict their conspiracy beliefs. We hypothesized that national identification would negatively predict the tendency to attribute responsibility to an in-group, thus predicting less risk-rejection conspiracy theory beliefs (e.g., COVID-19 is a hoax). In contrast, national collective narcissism would positively predict the tendency to attribute responsibility for the pandemic to an out-group, which in turn would validate conspiracy theories that acknowledge the risk of the pandemic (e.g., COVID-19 is a bioweapon). To test these predictions, we collected data in China (n = 1,200) in April 2020. Supporting our predictions, national identification was negatively associated with risk-rejection conspiracy beliefs via in-group attribution, whereas national collective narcissism was positively associated with risk-acceptance conspiracy beliefs via out-group attribution. © The Author(s) 2021.

15.
Journal of Rehabilitation ; 87(1):80-87, 2021.
Article in English | Scopus | ID: covidwho-1308662

ABSTRACT

Background: Relative to the general population, people with disabilities and chronic illnesses are in greater danger of contracting COVID-19 and for experiencing severe complications. Although it is established that people with multiple sclerosis (PwMS) are at increased risk for infection and complications due to immunocompromise, use of immunosuppressive therapies, and MS-related comorbidities, there has been relatively little longitudinal research on the psychosocial response of PwMS to the COVID-19 pandemic. Methods: We used an online survey to collect data before and during the pandemic. Using self-report measures, we investigated changes in psychological well-being, perceived stress, resilience, anxiety, and depression in response to the pandemic. Results: One hundred thirty-three respondents participated in the study. Participants had significantly increased negative feelings and depression when perceiving higher stress (e.g., irritability, lack of joy) and resilience (e.g., spiritual belief). Conclusions: The pandemic has affected mental health and psychosocial adjustment for PwMS. We found specific pandemic impacts on stress perception, resilience, and mental health. It is valuable to understand the different impacts of the pandemic on PwMS living in the community regarding transactional interpretations of stress, ways to keep resilient, and emotional responses. © 2021 National Rehabilitation Association. All rights reserved.

16.
PubMed; 2021.
Preprint in English | PubMed | ID: ppcovidwho-9281

ABSTRACT

Rapidly-emerging variants jeopardize antibody-based countermeasures against SARS-CoV-2. While recent cell culture experiments have demonstrated loss of potency of several anti-spike neutralizing antibodies against SARS-CoV-2 variant strains1-3, the in vivo significance of these results remains uncertain. Here, using a panel of monoclonal antibodies (mAbs) corresponding to many in advanced clinical development by Vir Biotechnology, AbbVie, AstraZeneca, Regeneron, and Lilly we report the impact on protection in animals against authentic SARS-CoV-2 variants including WA1/2020 strains, a B.1.1.7 isolate, and chimeric strains with South African (B.1.351) or Brazilian (B.1.1.28) spike genes. Although some individual mAbs showed reduced or abrogated neutralizing activity against B.1.351 and B.1.1.28 viruses with E484K spike protein mutations in cell culture, low prophylactic doses of mAb combinations protected against infection in K18-hACE2 transgenic mice, 129S2 immunocompetent mice, and hamsters without emergence of resistance. Two exceptions were mAb LY-CoV555 monotherapy which lost all protective activity in vivo, and AbbVie 2B04/47D11, which showed partial loss of activity. When administered after infection as therapy, higher doses of mAb cocktails protected in vivo against viruses displaying a B.1.351 spike gene. Thus, many, but not all, of the antibody products with Emergency Use Authorization should retain substantial efficacy against the prevailing SARS-CoV-2 variant strains.

17.
2021 Data Compression Conference, DCC 2021 ; 2021-March:360, 2021.
Article in English | Scopus | ID: covidwho-1247031

ABSTRACT

COVID-19 has made video communication one of the most important modes of information exchange. While extensive research has been conducted on the optimization of the video streaming pipeline, in particular the development of novel video codecs, further improvement in the video quality and latency is required, especially under poor network conditions. This paper proposes an alternative to the conventional codec through the implementation of a keypoint-centric encoder relying on the transmission of keypoint information from within a video feed, as shown in Figure 1. The decoder uses the streamed keypoints to generate a reconstruction preserving the semantic features in the input feed. Focusing on video calling applications, we detect and transmit the body pose and face mesh information through the network, which are displayed at the receiver in the form of animated puppets. Using efficient pose and face mesh detection in conjunction with skeleton-based animation, we demonstrate a prototype requiring lower than 35 kbps bandwidth, an order of magnitude reduction over typical video calling systems. The added computational latency due to the mesh extraction and animation is below 120ms on a standard laptop, showcasing the potential of this framework for real-time applications. The code for this work is available at http://github.com/shubhamchandak94/digital-puppetry/and the full version is available on arXiv [1]. © 2021 IEEE.

18.
PubMed; 2021.
Preprint in English | PubMed | ID: ppcovidwho-8845

ABSTRACT

Rapidly-emerging variants jeopardize antibody-based countermeasures against SARS-CoV-2. While recent cell culture experiments have demonstrated loss of potency of several anti-spike neutralizing antibodies against SARS-CoV-2 variant strains1-3, the in vivo significance of these results remains uncertain. Here, using a panel of monoclonal antibodies (mAbs) corresponding to many in advanced clinical development by Vir Biotechnology, AbbVie, AstraZeneca, Regeneron, and Lilly we report the impact on protection in animals against authentic SARS-CoV-2 variants including WA1/2020 strains, a B.1.1.7 isolate, and chimeric strains with South African (B.1.351) or Brazilian (B.1.1.28) spike genes. Although some individual mAbs showed reduced or abrogated neutralizing activity against B.1.351 and B.1.1.28 viruses with E484K spike protein mutations in cell culture, low prophylactic doses of mAb combinations protected against infection in K18-hACE2 transgenic mice, 129S2 immunocompetent mice, and hamsters without emergence of resistance. Two exceptions were mAb LY-CoV555 monotherapy which lost all protective activity in vivo, and AbbVie 2B04/47D11, which showed partial loss of activity. When administered after infection as therapy, higher doses of mAb cocktails protected in vivo against viruses displaying a B.1.351 spike gene. Thus, many, but not all, of the antibody products with Emergency Use Authorization should retain substantial efficacy against the prevailing SARS-CoV-2 variant strains.

19.
20th International Conference on Electronic Business, ICEB 2020 ; 2020-December:496-500, 2020.
Article in English | Scopus | ID: covidwho-1232897

ABSTRACT

Crowdfunding is an emerging industry in the past decades, which proliferates and has attracted an enormous population from the public to be involved in various funding projects in multiple fields such as business entrepreneurship, healthcare, and fintech. Meanwhile, charitable crowdfunding platforms such as GoFundMe, Indiegogo, and Kickstarter have allowed internet users to provide help and donation to the fundraisers directly. As the year 2020 is surrounded by the COVID-19 global pandemic spreading out the world, the topic of coronavirus relief has surged. Thus, it is worthy of evaluating the crowdfunding campaign's effectiveness during the coronavirus context by making a connection between fundraising activities and coronavirus relief. This paper aims to investigate the effects of various factors affecting a donation-based crowdfunding campaign for coronavirus relief of food donation in the United States and determine the significant factors affecting the campaign's success rate. To achieve this research purpose, secondary data were extensively collected from the crowdfunding platform GoFundMe for regression analysis. The sample data was derived from crowdfunding campaigns launched from March 1st, 2020, to May 31st, 2020. During this period, the United States was severely affected by the COVID-19 pandemic with an exponentially surged number of confirmed cases. This paper derives the independent variables that have been examined from previous studies and further applies in the coronavirus context to identify whether these factors are significant influencers to the success of crowdfunding campaigns for coronavirus relief of food donation. The factors being examined include target funding amount, the existence of spelling mistakes, the presence of pictures, video, social network sites, project updates, comments between fundraisers and backers, and links to external websites. That the significant factors contributing to a successful funding project are similar, as identified in previous reward-based and equity crowdfunding studies. On the other hand, several independent variables' effectiveness varied between the normal scenario and the coronavirus context, as such variables demonstrate a much compelling role to attract donors for the coronavirus relief activations. The analysis is valuable and worthy of different viewpoints. First, understanding the donor's motivation and the success features of funding projects is valuable for fundraisers to have a strategic mindset for decision-making criteria when initiating funding projects to attract more donors and the amount of money. Second, because of the lack of literature focusing on examining the success features for donation-based crowdfunding campaigns, this study fills the gap and further focus on the crowdfunding activations in the context of coronavirus food relief in the US. Therefore, this study provides significant insight to understand the dynamics of the donation-based crowdfunding campaign and provides a recommendation to develop coronavirus relief more efficiently. © 2020 International Consortium for Electronic Business. All rights reserved.

20.
Australian Prescriber ; 44(1):19-25, 2021.
Article in English | Web of Science | ID: covidwho-1102965

ABSTRACT

The novel coronavirus SARS-CoV-2, the cause of the COVID-19 pandemic, is a highly infectious human respiratory pathogen to which the global population had no prior immunity. The virus will likely continue to cause significant morbidity until there is a broadly effective vaccine. As of mid-December 2020, more than 200 COVID-19 vaccine candidates are in development and 11 have entered phase Ill clinical trials globally. All generate immunity to the viral spike glycoprotein. Three vaccine candidates have agreements for procurement and use in Australia if efficacy and safety requirements are met - one protein-based vaccine, one vaccine using a simian-derived adenovirus vector and one messenger RNA vaccine. The latter two vaccines have published interim analyses and efficacy results of their phase Ill trials. The messenger RNA vaccine is being rolled out in the UK, USA and Canada. Significant uncertainties remain. How well will some of those at highest risk of severe disease (such as older people aged >75 years and those with immunocompromising conditions) be protected by a vaccine, and for how long? Also, to what extent will vaccination protect against infection? This will determine the degree of indirect 'herd' protection needed through broad vaccine coverage of younger age groups.

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