A Mask Detection Algorithm Based on Improved Yolov5s

Aiming at the severe form of new coronavirus epidemic prevention and control, a target detection algorithm is proposed to detect whether masks are worn in public places. The Ghostnet and SElayer modules with fewer design parameters replace the BottleneckCSP part in the original Yolov5s network, which reduces the computational complexity of the model and improves the detection accuracy. The bounding box regression loss function DIOU is optimized, the DGIOU loss function is used for bounding box regression, and the center coordinate distance between the two bounding boxes is considered to achieve a better convergence effect. In the feature pyramid, the depthwise separable convolution DW is used to replace the ordinary convolution, which further reduces the amount of parameters and reduces the loss of feature information caused by multiple convolutions. The experimental results show that compared with the yolov5s algorithm, the proposed method improves the mAP by 4.6% and the detection rate by 10.7 frame/s in the mask wearing detection. Compared with other mainstream algorithms, the improved yolov5s algorithm has better generalization ability and practicability. © 2022 ACM.

Mutual Fund Liquidity Transformation and Reverse Flight to Liquidity

We identify fixed-income mutual funds as an important contributor to the unusually high selling pressure in liquid asset markets during the COVID-19 crisis. We show that mutual funds experienced pronounced investor outflows amplified by their liquidity transformation. In meeting redemptions, funds followed a pecking order by first selling their liquid assets, including Treasuries and high-quality corporate bonds, which generated the most concentrated selling pressure in these markets. Overall, the estimated price impact of mutual funds was sizable at a third of the increase in Treasury yields and a quarter of the increase in corporate bond yields during the COVID-19 crisis. © 2022 The Author(s). Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved.

Bridging the urban-rural gap: A qualitative examination of perceived access, barriers, risks and opportunities of children's digital learning during the COVID-19 pandemic

The COVID-19 pandemic has tremendously reshaped the landscape of education worldwide, shifting digital learning from a substitute to a possible necessity in a time of uncertainty. This study explored the digital learning experience for children in China during and after the lockdown periods from February 2020 to January 2022, with a particular focus on the urban-rural divide. Forty-eight semi-structured interviews were conducted with fifth- and sixth-grade students, parents and teachers to obtain multiple perspectives regarding children's digital learning in YY County in southwestern China. This study revealed that the urban-rural digital divide is not rooted in differences in minimal access to digital devices per se but rather in meaningful access to make full use of those devices for extended learning purposes. The major barriers that give rise to the digital divide include teachers' technology challenges, internet addiction among children and a lack of parental supervision of children's digital use. However, digital learning also offers an opportunity to address educational inequality. This study calls for empowering rural teachers and parents to better support children's digital needs and boost their digital learning experience. Well-designed virtual interventions, school- and community-based programmes and policy interventions are potential solutions to address the needs of rural teachers, parents and children.

Reliability and Lifetime of a Novel 222-nm KrCl Excilamp

Recent studies in the epidermis have shown that Far-UVC (200-230nm) is a promising candidate against Novel Coronavirus (SARS-Cov-2) with little DNA damage. Due to the consideration that conventional Far-UVC KrCl excilamps may emit 200-230 nm radiation (typically 222-nm peak wavelength) but with some harmful UV radiation beyond 230 to 280 nm, a novel design of Far-UVC KrCl excilamps with the filter and reflector is introduced to reduce the harmful UV radiation from 10.9% to 2.5% at the cost of 30%similar to 40% reduction in the total irradiance. In our study, the radiant characteristics and service life of the novel Far-UVC KrCl excilamps of 40 similar to 75 Watt (electrical power) with 222-nm peak wavelength were investigated. The service life was assessed under aging at the ambient temperatures (T-a) of 25 degrees C and 85 degrees C for 500 hours, respectively. The results showed that both the ambient temperature and the root mean square of current (I-rms) into the excilamps have a substantial effect on the lifetime of the KrCl excilamps. Furthermore, although no significant change of the off-nominal emission ratio existed during the lifetime test, it was observed that the high ambient temperature has a negative effect on the filtering of the harmful radiation.

The Mechanisms of Luteolin in Treating COVID-19 Based on Bioinformatics Analysis and Molecular Docking

Luteolin is a natural flavonoid that has a variety of pharmacological activities, such as anti-inflammatory, anti-allergic, anti-bacterial, anti-viral, apoptosis inhibition, cell autophagy regulation, and anti-tumor activity. It is one of the main ingredients of an expert-recommended herbal formula for the prevention and treatment of coronavirus disease 2019 (COVID-19). This suggests that luteolin has strong pharmacological effects on the prevention and treatment of COVID-19. The aims of this study were to identify the molecular targets of luteolin and to infer the possible mechanisms by which it exerts its pharmacological effects. The GSE159787 data set was obtained from the Gene Expression Omnibus online database, and differentially expressed genes were analyzed. There were 22 upregulated differentially expressed genes enriched in the COVID-19 signaling pathway, suggesting that the upregulation of these genes may be closely related to the occurrence of COVID-19. Molecular docking results showed that luteolin had strong binding efficiency to 20 of these 22 key genes. Six of these genes (CFB, EIF2AK2, OAS1, MAPK11, OAS3, and STAT1) showed strong binding activity. Luteolin can regulate the COVID-19 signaling pathway by combining with these targets, which may have a therapeutic effect on COVID-19. © Wolters Kluwer Health, Inc. All rights reserved.

Reliability and Lifetime of a Novel 222-nm KrCl Excilamp

Recent studies in the epidermis have shown that Far-UVC (200-230nm) is a promising candidate against Novel Coronavirus (SARS-Cov-2) with little DNA damage. Due to the consideration that conventional Far-UVC KrCl excilamps may emit 200-230 nm radiation (typically 222-nm peak wavelength) but with some harmful UV radiation beyond 230 to 280 nm, a novel design of Far-UVC KrCl excilamps with the filter and reflector is introduced to reduce the harmful UV radiation from 10.9% to 2.5% at the cost of 30%~40% reduction in the total irradiance. In our study, the radiant characteristics and service life of the novel Far-UVC KrCl excilamps of 40~75 Watt (electrical power) with 222-nm peak wavelength were investigated. The service life was assessed under aging at the ambient temperatures (Ta) of 25 and 85 for 500 hours, respectively. The results showed that both the ambient temperature and the root mean square of current (Irms) into the excilamps have a substantial effect on the lifetime of the KrCl excilamps. Furthermore, although no significant change of the off-nominal emission ratio existed during the lifetime test, it was observed that the high ambient temperature has a negative effect on the filtering of the harmful radiation. © 2023 IEEE.

Efficient, Breathable and Biodegradable Filter Media for Face Masks

The global outbreak of COVID-19 results in the surge of disposable sanitary supplies, especially personal protective face masks. However, the charge dissipation of the electret meltblown nonwovens, which predominate in the commercial face mask filters, confines the durability and safety of commercial face masks. Furthermore, most of the face masks are made from nondegradable materials (such as PP) or part of their degradation products are toxic and contaminative to the environment. Herein, a type of face mask with biodegradable and highly effective PLA bi-layer complex fibrous membrane as filter core is reported. The prepared PLA complex membrane possesses a high-filtration efficiency of 99.1% for PM0.3 while providing a favorable pressure drop of 93.2 Pa. With the PLA complex membrane as the filter core, our face mask exhibits comparable or even higher wearability to commercial face masks, which further manifests our designed PLA complex membrane a promising filter media for face masks. © 2023, The Author(s), under exclusive licence to the Korean Fiber Society.

The design and implementation of the all-in-one machine for killing and sorting in the small and medium-sized logistics center

To stop the COVID-19 spread, artificial intelligence and new technologies are also actively participating in the battle. For fighting against the virus, disinfection is one of the effective ways to block the spread of the virus. According to the preliminary market research, only in the large distribution centers is the operator-controlled machine disinfection, at present most of the small and medium-sized express logistics stations are through human resources to carry out disinfection, and sorting of express packages, so the dependence on human costs, medical resources can be imagined. To this end, we designed ultrasonic atomization disinfection, sorting, and whole load notification integrated machine based on deep learning [1] and Internet of Things [2] technology to cope with the trend of normalization and recurrence of the epidemic. After testing logistics with different labels, the experimental results show that the system can effectively distinguish different labels and carry out a series of operations such as disinfection, sorting, and notification of full load, which can be put into production and contribute to epidemic prevention work. © 2023 IEEE.

Changes of knowledge attitude and practice in different stages of the COVID-19 epidemic among college students in Shanghai

Objective To investigate and compare the changes and associated factors of knowledge attitude and practice of college students in Shanghai between the early 2020 and the end of 2021 stages of the COVID-19 epidemic and analyze the influencing factors so as to provide reference for epidemic prevention and health education of college students. Methods A retrospective cross-sectional survey was conducted among 913 college students in 12 colleges and universities in Shanghai in 2021 from November to December with a self-designed questionnaire by multi-stage stratified cluster sampling so as to investigate the changes of college students, health literacy related to COVID-19 and the changes of knowledge attitude and practice between the early 2020 and the end of 2021 stages of the COVID-19 epidemic. Results In the early stage of the epidemic the average score of understanding of epidemic prevention and control policies was 2.93±0.94 information judgment was 3.10±0.89 satisfaction degree was 4.11± 1.09 cooperation degree was 4.31±0.96 communication intention was 3.91±1.15. By the end of 2021 the understanding of prevention and control policies was 2.95±0.98 Information judgment was 3.77±0.94 satisfaction degree was 4.22±1.10 cooperation degree was 4.36±0.99 communication intention was 3.97±1.20 there were significant changes at different stages P<0.01. The results of binary Logistic regression showed that majors of social sciences OR = 0.62 majors of natural sciences OR = 0.62 self-rated good health OR = 0.62 and self-rated relatively good health OR = 0.28 were negatively correlated with college students, cognition and attitude changes to the COVID-19 epidemic P<0.05 while the choice of "relatively consistent" OR = 3.31 in "change in health behavior according to reasonable health information" was positively correlated with knowledge and attitude changes P<0.05. Shanghai college students, health literacy about epidemic prevention was generally high. 79.4% of them had a "relatively high" score >80 and 82.6% of the students rated themselves "very well" and "relatively well" knew epidemic prevention. Conclusion Relatively high level of health literacy on epidemic prevention is observed among college students in Shanghai. There had been significant changes in their knowledge attitude and practice of the epidemic since the early stage. It is necessary to carry out more accurate and effective health education and dissemination according to different characteristics so as to build the prevention and control barrier of epidemic among college students. © 2022 by the Author(s).

Progress of the Panama Meeting of the Convention on International Trade in Endangered Species of Wild Fauna and Flora

Background: The 19th meeting of the Conference of the Parties (CoP 19) to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) took place in Panama from the 14th to the 25th of November 2022. The meeting was attended by 2,500 delegates representing more than 160 Parties and observers to the Convention. The COVID-19 pandemic impacted all CITES Parties and significantly disrupted the implementation of CITES. The CoP shared the actions and the experiences of the Parties, the Secretariat, the Committee members and observers in the face of the COVID-19 pandemic. Progress: Delegates reviewed 52 proposed amendments to the Appendices and discussed 91 agenda items. There was the highest proportion of proposals for new Appendix II species but the lowest number of revising annotation proposals the CoP 19 has considered in nearly 25 years. The CoP updated the regulation of international trade in over 600 species of animals and plants. In the adopted proposals, international trade in 50 species of freshwater turtles, 158 species of glass frogs, 100 species of sharks and rays, 150 species of trees and dozens of species of roseroots will be regulated as the newly revised lists are enforced. The CoP adopted the financing and the cost of the programme of work for the triennium 2023‒2025, with an overall budget being 6.1% higher compared to the triennium 2020‒2022. The Conference further refined compliance and enforcement requirements for elephants, big cats, totoaba and other wildlife species threatened with extinction. With the implementations of engagement of indigenous peoples and local communities, livelihoods-related issues have been relatively slow and hampered. Parties vigorously debated proposed amendments to the Rules of Procedure and criteria for the amendments of CITES Appendices, but no substantive amendments were adopted. A pilot version of the World Wildlife Trade Report and the Assessment Report on the Sustainable Use of Wild Species: Policy-Maker Summary were discussed and heard. CITES has added several new topics in the CoP to address new challenges, such as the role of CITES in reducing the risk of future zoonotic diseases associated with the international wildlife trade. The CoP 19 recommends interdisciplinary research to analyze the role of CITES in the conservation and sustainable use of forests. The Parties resolved to work on building gender equality into the international trade in wildlife, recognizing that women are often guardians of wildlife and biodiversity but, just as often, are not recognized or benefit from this trade. Prospects: Regardless of the challenges posed by the COVID-19 pandemic, China's CITES authorities made thorough preparations for the CoP, conducting research two years in advance and drafting a proposal a report which was submitted to the CoP 19, organized pre-session and in-session consultations with scientific authorities, collected information from all parties, and actively led the discussions in working groups, presenting a positive view of China in prioritizing ecological civilization and fulfilling its responsibilities as a major country. CITES will celebrate its 50th anniversary in 2023. The record 365 decisions in CoP 19 demonstrate that CITES Parties continue to take action to address the unprecedented pressures on species due to overexploitation and illegal trade. © 2023, Chinese Academy of Sciences. All rights reserved.

Progress of the Panama Meeting of the Convention on International Trade in Endangered Species of Wild Fauna and Flora

Background: The 19th meeting of the Conference of the Parties (CoP 19) to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) took place in Panama from the 14th to the 25th of November 2022. The meeting was attended by 2,500 delegates representing more than 160 Parties and observers to the Convention. The COVID-19 pandemic impacted all CITES Parties and significantly disrupted the implementation of CITES. The CoP shared the actions and the experiences of the Parties, the Secretariat, the Committee members and observers in the face of the COVID-19 pandemic. Progress: Delegates reviewed 52 proposed amendments to the Appendices and discussed 91 agenda items. There was the highest proportion of proposals for new Appendix II species but the lowest number of revising annotation proposals the CoP 19 has considered in nearly 25 years. The CoP updated the regulation of international trade in over 600 species of animals and plants. In the adopted proposals, international trade in 50 species of freshwater turtles, 158 species of glass frogs, 100 species of sharks and rays, 150 species of trees and dozens of species of roseroots will be regulated as the newly revised lists are enforced. The CoP adopted the financing and the cost of the programme of work for the triennium 2023‒2025, with an overall budget being 6.1% higher compared to the triennium 2020‒2022. The Conference further refined compliance and enforcement requirements for elephants, big cats, totoaba and other wildlife species threatened with extinction. With the implementations of engagement of indigenous peoples and local communities, livelihoods-related issues have been relatively slow and hampered. Parties vigorously debated proposed amendments to the Rules of Procedure and criteria for the amendments of CITES Appendices, but no substantive amendments were adopted. A pilot version of the World Wildlife Trade Report and the Assessment Report on the Sustainable Use of Wild Species: Policy-Maker Summary were discussed and heard. CITES has added several new topics in the CoP to address new challenges, such as the role of CITES in reducing the risk of future zoonotic diseases associated with the international wildlife trade. The CoP 19 recommends interdisciplinary research to analyze the role of CITES in the conservation and sustainable use of forests. The Parties resolved to work on building gender equality into the international trade in wildlife, recognizing that women are often guardians of wildlife and biodiversity but, just as often, are not recognized or benefit from this trade. Prospects: Regardless of the challenges posed by the COVID-19 pandemic, China's CITES authorities made thorough preparations for the CoP, conducting research two years in advance and drafting a proposal a report which was submitted to the CoP 19, organized pre-session and in-session consultations with scientific authorities, collected information from all parties, and actively led the discussions in working groups, presenting a positive view of China in prioritizing ecological civilization and fulfilling its responsibilities as a major country. CITES will celebrate its 50th anniversary in 2023. The record 365 decisions in CoP 19 demonstrate that CITES Parties continue to take action to address the unprecedented pressures on species due to overexploitation and illegal trade. © 2023, Chinese Academy of Sciences. All rights reserved.

Virtual Supply Chain Network Platform Design and Development for Crisis Response

The COVID-19 pandemic exposed the vulnerability of the Canadian economy on many fronts. When the demand for lifesaving equipment increased globally, the supply chain networks were broken by the direct involvement of other countries. The rising competition and interruptions caused Canada to face significant difficulties in global markets to secure critical medical equipment and protective materials. Not only hospitals and healthcare workers but also the public and patients had no access to the needed equipment even though companies and organizations in the country have the required capacity and resources. In such emergency times, Canada should produce the essential equipment within the country. We propose a four-step strategic product manufacturing system to ensure crisis response. The first and second steps are creating a manufacturing capability database of Canadian companies and a library of product families, respectively. These two steps should be completed before the crisis. The third step involves emergency need analysis, equipment design and forecasting. Finally, the fourth step is developing a virtual supply chain network platform through which the procurement, production, and transportation activities will be scheduled based on the capability database, product families library, and requirements analysis in the most efficient and economical way possible. The research utilizes various tools such as forecasting, optimization, simulation, multi-criteria decision making, and engineering design tools. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

A grid management system for COVID-19 antigen detection based on image recognition

Objective: To develop a SARS-CoV-2 antigen detection management system for Chinese residents under community grid management, which is supported by "health information technology" and "neural network image recognition", so as to give full play to the advantages of "grid management". This system is applied to the normalized prevention and control of COVID-19 epidemic. Method(s): The model of image recognition algorithm was built based on deep learning and convolution neural network (CNN) artificial intelligence algorithm. The improved Canny edge detection algorithm was used to monitor and locate the image edge, and then the image segmentation and judgment value calculation were completed according to projection method. The system construction was completed combing with the grid number design. Result(s): The proposed method had been tested and showed the accuracy of the algorithm. With a certain robustness, the algorithm error was proved to be small. Based on the image recognition algorithm model, the development of SARS-CoV-2 antigen detection management system covering user login, paper-strip test image upload, paper-strip test management, grid management, grid warning and regional traffic management was completed. Conclusion(s): Antigen detection is an important supplementary means of COVID-19 epidemic prevention and control in the new stage. The SARS-CoV-2 antigen detection management system for Chinese residents under community grid managemen based on image recognition enables mobile communication devices to recognize the image of SARS-CoV-2 antigen detection results, which is helpful to form a grid management mode for the epidemic and improve the management framework of epidemic monitoring, detection, early warning and prevention and control.Copyright © 2023 The Authors

An empirical study on factors affecting purchase intention of cross-border e-commerce consumer in post-pandemic era

The outbreak of COVID-19 promoted the further development of the Cross-border E-commerce (CBEC) industry worldwide. Due to lockdown and home quarantine policies, many countries across the globe followed the complete closure of shopping malls, transport networks, schools, universities, etc. This study aims to investigate factors that influence purchase intention of consumers in CBEC in post-pandemic era. Stimulus-Organism-Response (SOR) model, along with Howard-Sheth Model of consumer behavior and Technology Acceptance Model (TAM) has been employed to develop a structural model for the research. An empirical study including 322 copies of questionnaire were collected and were analyzed by SPSSAU. It has been found that input stimuli such as significant stimuli, symbol stimuli, social stimuli affect personal perception, while personal perception such as perceived risk, perceived usefulness and perceived ease of use affect purchase intention negatively or positively. Based on the study, suggestions were put forward for CBEC platform for further development. © 2022 International Consortium for Electronic Business. All rights reserved.

Understanding consumers' motivations to view travel live streaming: Scale development and validation

Since the outbreak of COVID-19, travel live streaming has been increasingly implemented by online travel agents as an effective approach for economic recovery. However, little is known about users' motivations for participating in this activity. This study aims to understand Chinese customers' motivations by developing a measurement scale based on in-depth interviews and surveys. Eight motivators were extracted: socializing & belonging, media engagement, remuneration, product examination, relaxation & escape, entertainment & novelty, self-development, and immersion experience. This study deepens the understanding of China's live-streaming business and the preferences of tourists, inspiring future product design and marketing. © 2022 Elsevier Ltd

Ten measures to fight against the 2019-nCoV pneumonia in West China Hospital.

After the occurrence of public health emergencies, as the most direct front position, how to carry out medical treatment orderly, effectively, rapidly and safely in a short time has become the focus and difficulty of epidemic control. After the outbreak of 2019 novel coronavirus pneumonia (2019-nCoV), West China Hospital of Sichuan University, as a large-scale general hospital under the supervision of the CPC central committee, put people's life safety and health first, and attach great importance to the prevention and control of the epidemic. This paper introduces the ten measures taken by West China Hospital of Sichuan University to fight against the 2019-nCoV pneumonia, in order to provide reference for other hospitals. Copyright © 2020 West China University of Medical Science. All rights reserved.

Quantitative assessment of the effects of resource optimization and ICU admission policy on COVID-19 mortalities

It is evident that increasing the intensive-care-unit (ICU) capacity and giving priority to admitting and treating patients will reduce the number of COVID-19 deaths, but the quantitative assessment of these measures has remained inadequate. We develop a comprehensive, non-Markovian state transition model, which is validated through the accurate prediction of the daily death toll for two epicenters: Wuhan, China and Lombardy, Italy. The model enables prediction of COVID-19 deaths in various scenarios. For example, if appropriate treatment priorities had been used, the death toll in Wuhan and Lombardy would have been reduced by about 10% and 7%, respectively. The strategy depends on the epidemic scale and is more effective in countries with a younger population structure. Analyses of data from China, South Korea, Italy, and Spain suggest that countries with less per capita ICU medical resources should implement this strategy in the early stage of the pandemic to reduce mortalities. We emphasize that the results of this paper should be interpreted purely from a scientific and a quantitative-analysis point of view. No ethical implications are intended and meaningful. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

How Cultural Diversity Influences Students' Online Learning Engagement with Online Technologies - A Narrative Analysis

Since the outbreak of the COVID-19 pandemic early in 2020, it had versed the learning mode of offline into online teaching and learning in many parts of the world, while students from different cultural backgrounds may have different perceptions and responses toward online learning. Students' engagement, particularly the emotional dimension is discussed in this study to evaluate different students' perceptions about online learning to represent how culture impact on students' online learning by using Bamberg (1997)'s narrative analysis. 48 interviews were held and 2 interviews of their participants from Macau and Mainland China were particularly picked out to represent how students from different cultural backgrounds are going to position themselves in the discourse of online learning engagement with the involvement of online technologies. Through this study, it was found that students from the high-context cultural learning background (Macau) would hold a more positive attitude with online learning activities compared to students from the low-context learning context, position themselves as relaxed online capabilities. While students from a relatively low-context cultural background (Mainland China) eager to pursue high-efficiency of learning, with a negative attitude towards online learning, position themselves as positive efficiency seekers, underestimate the high-ambiguity and low-efficiency of online learning. Hence, after the rough understanding of students' different perceptions of online learning from different cultural backgrounds, this study further proved the influence of different cultures on learning engagement and provided some implications from different perspectives for pedagogical implementation and instructors to improve online curriculum design. © 2022 ACM.