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We used a lodging platform's big data to investigate the factors that were associated with consumers' reviews during the pandemic. A univariate analysis and fixed effects model analysis were conducted on an unbalanced panel dataset of 84,915 listings in Los Angeles and 16,143 listings in San Francisco over 21 months. Results showed that review ratings were higher for more COVID-19 cases, super host, and instantly bookable; however, negative associations were found with price, number of reviews, and host listing numbers. The profound implications brought by COVID-19 required online booking platforms to seek ways to improve customer satisfaction to survive. The key was to understand the new needs and requirements for travelers during COVID-19. [ABSTRACT FROM AUTHOR]

The pandemic caused by SARS-CoV-2 has a huge impact on the global economy. SARS-CoV-2 could possibly and potentially be transmitted to humans through cold-chain foods and packaging (namely good-to-human), although it mainly depends on a human-to-human route. It is imperative to develop countermeasures to cope with the spread of viruses and fulfil effective surveillance of cold-chain foods and packaging. This review outlined SARS-CoV-2-related cold-chain food incidents and current methods for detecting SARS-CoV-2. Then the needs, challenges and practicable countermeasures for SARS-CoV-2 detection, specifically for cold-chain foods and packaging, were underlined. In fact, currently established detection methods for SARS-CoV-2 are mostly used for humans; thus, these may not be ideally applied to cold-chain foods directly. Therefore, it creates a need to develop novel methods and low-cost, automatic, mini-sized devices specifically for cold-chain foods and packaging. The review intended to draw people's attention to the possible spread of SARS-CoV-2 with cold-chain foods and proposed perspectives for futuristic cold-chain foods monitoring during the pandemic. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic compelled the global and abrupt conversion of conventional face-to-face instruction to the online format in many educational institutions. Urgent and careful planning is needed to mitigate negative effects of pandemic on engineering education that has been traditionally content-centered, hands-on and design-oriented. To enhance engineering online education during the pandemic, we conducted an observational study at California State University, Long Beach (one of the largest and most diverse four-year university in the U.S.). A total of 110 faculty members and 627 students from six engineering departments participated in surveys and answered quantitative and qualitative questions to highlight the challenges they experienced during the online instruction in Spring 2020. Our results identified various issues that negatively influenced the online engineering education including logistical/technical problems, learning/teaching challenges, privacy and security concerns and lack of sufficient hands-on training. For example, more than half of the students indicated lack of engagement in class, difficulty in maintaining their focus and Zoom fatigue after attending multiple online sessions. A correlation analysis showed that while semi-online asynchronous exams were associated with an increase in the perceived cheating by the instructors, a fully online or open-book/open-note exams had an association with a decrease in instructor's perception of cheating. To address various identified challenges, we recommended strategies for educational stakeholders (students, faculty and administration) to fill the tools and technology gap and improve online engineering education. These recommendations are practical approaches for many similar institutions around the world and would help improve the learning outcomes of online educations in various engineering subfields. As the pandemic continues, sharing the results of this study with other educators can help with more effective planning and choice of best practices to enhance the efficacy of online engineering education during COVID-19 and post-pandemic. [ABSTRACT FROM AUTHOR]

The pandemic of coronavirus disease 2019 (COVID-19) resulted from novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a worldwide concern. It is imperative to develop rapid, sensitive, and specific biosensing methods. Herein, we developed a CRISPR-Cas12a powered visual biosensor with a smartphone readout for ultrasensitive and selective detection of SARS-CoV-2. Simply, the SARS-CoV-2 derived nucleic acids triggered CRISPR-Cas12a based indiscriminate degradation of a single-stranded DNA that was supposed to link two gold nanoparticles, inducing the dis-aggregation of gold nanoparticles and thus generating observable color changes. This change can be readily distinguished by naked eyes as well as a smartphone with a Color Picker App. The proposed biosensor was successfully applied to detect SARS-CoV-2 gene in synthetic vectors, transcribed RNA and SARS-CoV-2 pseudoviruses. It rendered "single copy resolution" as evidenced by the 1 copy/μL limit of detection of pseudoviruses with no cross-reactivity. When the developed biosensor was challenged with SARS-CoV-2 clinical bio-samples, it provided 100% agreement (both positive and negative) with qPCR results. The sample-to-result time was roughly 90 min. Our work provides a novel and robust technology for ultrasensitive detection of SARS-CoV-2 that could be used clinically. • A smartphone-read CRISPR-Cas12a powered visual biosensor was developed. • This biosensor was capable of detecting SARS-CoV-2 gene in synthetic vectors, transcribed RNA and SARS-CoV-2 pseudoviruses. • The limit of detection for SARS-CoV-2 pseudoviruses was 1 copy/μL with no cross-reactivity. • The biosensor showed 100% positive and 100% negative agreement with qPCR results for clinical samples detection. [ABSTRACT FROM AUTHOR]