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Blockchain protocols require nodes to verify all received transactions before forwarding them. However, massive spam transactions cause the participants in blockchain systems to consume many resources in verifying and propagating transactions. This paper proposes a reputation-based mechanism to increase the efficiency of processing transactions by considering the reputations of the sending nodes. Reputations are in turn adjusted based on the quality of transaction processing. Our proposed reputation-based mechanism offers three main contributions. First, we modify the verification strategy so that nodes set a probability of verifying a received transaction considering the likelihood of it being spam: transactions from a node with a low reputation have a high probability of being verified. Second, we optimize the transaction forwarding protocol to reduce propagation delay by prioritizing forwarding transactions to reputable receivers. Third, we design a data request protocol that provides alternative data exchange methods for nodes with different reputations. A series of simulations demonstrate the performance of our reputation-based mechanism. [ABSTRACT FROM AUTHOR]

Objectives Access to cross-jurisdictional data can be beneficial to researchers but challenges exist in accessing data from different legal jurisdictions and policy environments. Two national networks in Australia and Canada will share their respective approaches to supporting the discovery of, and coordinating applications and approvals for, cross-jurisdictional data access. Approach Collaboration between these two networks in the last year have allowed members to gain a better understanding of the approaches that have been put in place to support the coordination of cross-jurisdictional data applications. Through regular inter-network discussion and joint workshops, we have gained insight into the similarities, differences and challenges faced by each and identified common goals for continued shared learnings. Results Similarities and differences exist between the approach and processes each network has implemented to coordinate applications for cross-jurisdictional data. In both countries, a single point of contact model has been key in coordinating data requests centrally. Whereas in one country, virtual access to linked data is provided centrally, different legal and policy environments across jurisdictions in another country are barriers to accessing data in one location. Each network has developed processes and tools to meet researcher needs while respecting local requirements and are turning to innovative strategies. For example, one network is developing infrastructure to support analysis of data in a distributed way, and both groups are creating centralized tools to streamline the data discovery and access processes to improve researcher experience. Conclusion The coordination of applications for cross-jurisdictional data access by two national networks has streamlined researcher access, but challenges exist to fully meet researcher needs for cross-jurisdictional analyses. The continued cross-network collaboration will allow for shared learning opportunities and development of innovative solutions to tackle challenges related to cross-jurisdictional data access.

The Coronavirus pandemic has surprised the world and social media was extremely used to express frustrations and development of the cases found. Social media tools, such as Twitter, show a comparable impact with the number of tweets related to COVID -19 indicating remarkable development in a limited ability to focus time. The purpose of this paper is to investigate the impact of Coronavirus on the United States of America (USA) and New Zealand (NZ), and how that is reflected in a sentiment analysis through the examination of American and New Zealand tweets. We have gathered tweets from a March 2020 -- August 2020 and used sentiment extraction on the tweets. The major finding of this sentiment extraction is the fact that the overall average sentiment over the 5-month period stayed in a negative range in the USA and NZ. This paper aims to analyze these trends, identify patterns, and determine whether these trends were caused by the COVID-19 pandemic or outside sources. One trend that was analyzed was the spike of COVID-19 results in relation to the number of protests occurring in the USA. [ABSTRACT FROM AUTHOR]

The article focuses on the negative feasibility assessment for establishing a Biological Exposure Index (BEI) for 1-bromopropane, a chemical used in various industries, due to inadequate scientific data. Topics discussed include the call for additional data, the potential health risks associated with 1-bromopropane exposure, and the need for field or experimental studies to establish a BEI and improve risk management.