ABSTRACT
Several endemic corona viruses (eCoVs) have been reported to be the most common etiologic agents for the seasonal common cold and also cause pneumonia. These eCoVs share extensive sequence homology with SARS-CoV-2, and immune responses to eCoVs can cross-react with SARS-CoV-2 antigens. Based on such cross-reactivity of antigens among eCoVs, the IgG antibodies against the spike protein (SP) of severe acute respiratory syndrome coronavirus (SARS-CoV) were isolated from pig serum using magnetic beads immobilized with SARS-CoV SP and a protein-A column. The selectivity of the isolated antibodies was tested using different types of antigens, such as SARS-CoV-2 nucleoprotein (NP), influenza A virus (Beijing type), influenza B virus (Tokio and Florida types), human hepatitis B virus surface antigen (HBsAg), and bovine serum albumin (BSA). From the selectivity test, the anti-SP antibodies isolated from pig serum had sufficient selectivity to other kinds of viral antigens, and the apparent binding constant of the isolated antibodies was approximately 1.5 × 10-8 M from the surface plasmon resonance (SPR) measurements. Finally, the isolated anti-SP antibodies were applied to the immunoassay of SP using competitive immunoassay configuration. The feasibility of the detection as well as the quantitative analysis of the SARS-CoV viral culture fluid was determined using four viral culture samples, namely, SARS-CoV, SARS-CoV-2, MERS-CoV, and CoV-229E.
ABSTRACT
Social distancing to reduce the spread of coronavirus disease 2019 (COVID-19) made a huge increase in the global OTT market, and OTT service providers get millions of new subscribers. Recently OTT service providers are extending their service to video broadcasting. As a one type of video broadcasting, this paper covers multimedia streaming with multiple sources. Multimedia streaming with multiple sources has multiple sources, and receivers can select one specific source to watch the video from the source. Sources include cameras capturing different angles of same event or location, cameras in geographical locations, etc. For delivering video to rapidly increasing number of users, multimedia streaming with multiple sources system needs efficient and scalable delivery method. Tree-based Peer-to-peer (P2P) networking has been investigated as the delivery solution of multimedia streaming with multiple sources, and set-top boxes or mobile apps of OTT service can be used as peers connecting the subscriber of OTT service. However, the scalability of the tree-based P2P networking is limited by the out-degree of a tree that branches linearly with the number of users. Hence, this study proposes clustering peers based on the location proximity of the peers to enhance the scalability of the P2P multimedia streaming with multiple sources. By clustering peers, one or more peers can be grouped into a virtual peer with an aggregated uplink/downlink capacity. This paper describes P2P multimedia streaming with multiple sources and algorithms for the proposed clustering method. Two applications which are one-view multiparty video conferencing and multi-view video streaming are introduced, and considerations for applying the proposed method to the applications are also discussed. The experimental results show that location-proximity-based clustering is effective in achieving a scalable P2P multimedia streaming with multiple sources by reducing the out-degree of a tree for the introduced applications. The proposed clustering leads improvement in the maximum achievable video bit rate, the average viewing video bit rate, and perceived delay.