Underground forums provide useful insights into cybercrime, where researchers analyse underlying economies, key actors, their discussions and interactions, as well as different types of cybercrime. ...This interdisciplinary topic of study incorporates expertise from diverse areas, including computer science, criminology, economics, psychol-ogy, and other social sciences. Historically, there were sig-nificant challenges around access to data, but there are now research datasets of millions of messages scraped from underground forums. The problems now stem from the size of these datasets and the technical nature of methods and tools available for data sampling and analysis at scale, which make data exploration difficult for non-technical users. Postcoghas been developed to solve this problem. We first provide a survey of prior work into underground forums; this was used to understand the requirements and functionalities valued by researchers, and to inform the design of a data exploration tool. We then describe Postcog,a web application developed to support users from both technical and non-technical backgrounds in forum analyses, such as search, information extraction and cross-forum comparison. The prototype's usability is then evaluated through two user studies with expert users of the Crimebbdataset. Postcogis made available for academic research upon signing an agreement with the Cambridge Cybercrime Centre.
Turning Up the Dial Vu, Anh V.; Hughes, Jack; Pete, Ildiko ...
Proceedings of the ACM Internet Measurement Conference,
10/2020
Conference Proceeding
Odprti dostop
Trust and reputation play a core role in underground cybercrime markets, where participants are anonymous and there is little legal recourse for dispute arbitration. These underground markets exist ...in tension between two opposing forces: the drive to hide incriminating information, and the trust and stability benefits that greater openness yields. Revealing information about transactions to mitigate scams also provides valuable data about the market. We analyse the first dataset, of which we are aware, about the transactions created and completed on a well-known and high-traffic underground marketplace, Hack Forums, along with the associated threads and posts made by its users over two recent years, from June 2018 to June 2020. We use statistical modelling approaches to analyse the economic and social characteristics of the market over three eras, especially its performance as an infrastructure for trust. In the Set-up era, we observe the growth of users making only one transaction, as well as 'power-users' who make many transactions. In the Stable era, we observe a wide range of activities (including large-scale transfers of intermediate currencies such as Amazon Giftcards) which declines slowly from an initial peak. Finally, we analyse the effects of the Covid-19 pandemic, concluding that while we see a significant increase in transactins across all categories, this reflects a stimulus of the market, rather than a transformation. New users overcome the 'cold start' problem by engaging in low-level currency exchanges to prove their trustworthiness. We observe currency exchange accounts for most contracts, and Bitcoin and PayPal are the preferred payment methods by trading values and number of contracts involved. The market is becoming more centralised over time around influential users and threads, with significant changes observed during the Set-up and Covid-19 eras.
SUMMARY
Understanding mechanisms that regulate nitric oxide (•NO) function in the vascular compartment is critical in the context of transfusion‐based therapeutics. The role of hemoglobin (Hb), ...either cell‐free or encapsulated within the erythrocyte, has received much attention owing largely to the rapid rate of reactions between •NO and either oxy‐ or deoxyheme. In this review, we discuss the different mechanisms proposed by which •NO reactions with Hb are controlled under physiological conditions and which involve both preventing •NO‐scavenging by Hb and erythrocyte (and Hb)‐dependent stimulation of NO‐signaling. How these mechanisms may be utilized therapeutically in the design and application of Hb‐based oxygen carrier therapeutics is also discussed.
Medicaid claims data were analyzed to investigate the prevalence and cost of rheumatoid arthritis (RA) in the Medi-Cal program. It was estimated that approximately 24,000 Medi-Cal recipients receive ...treatment for RA each year. The sample of Medi-Cal RAs studied averaged more than $2500 annually in total direct health care expenditures. The total cost of RA to Medi-Cal is projected to be $19.26 million (+/- $0.90 million) annually. Inclusion of possible gastrointestinal side effects of drug therapy increases the total cost to $20.49 million (+/- $0.91 million). While only 6.5% of the sample of RAs were hospitalized and 4.9% received nursing home care annually, these services are estimated to account for nearly 70% of RA-related expenditures. Less than 7% of Medi-Cal RAs receive disease modifying antirheumatic drugs (DMARDs). More than 75% of Medi-Cal RAs received aspirin or NSAIDs. These relieve pain and inflammation, but have not been demonstrated to halt the process of joint destruction.
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