Hui Yu

The recent paradigm of mobile crowd sensing (MCS) enables a broad range of mobile applications. A critical challenge for the paradigm is to incentivize phone users to be workers providing sensing services. While some theoretical incentive mechanisms for general-purpose crowdsourcing have been proposed, it is still an open issue as to how to incorporate the theoretical framework into the practical MCS system. In this paper, we propose an incentive mechanism based on a quality-driven auction (QDA). The mechanism is specifically for the MCS system, where the worker is paid off based on the quality of sensed data instead of working time, as adopted in the literature. We theoretically prove that the mechanism is truthful, individual rational, platform profitable, and social-welfare optimal. Moreover, we incorporate our incentive mechanism into a Wi-Fi fingerprint-based indoor localization system to incentivize the MCS-based fingerprint collection. We present a probabilistic model to evaluate the reliability of the submitted data, which resolves the issue that the ground truth for the data reliability is unavailable. We realize and deploy an indoor localization system to evaluate our proposed incentive mechanism and present extensive experimental results.

BACKGROUND: Real-world data quantifying the costs of increasing use of biologics in inflammatory bowel disease (IBD) are unknown. AIM: To determine the outpatient IBD drug utilization trends, relative market share, and costs in the USA during a 9-year period. METHODS: Database was analysed for patients with Crohn's disease (CD) and ulcerative colitis (UC) during 2007-2015. National drug codes were used to identify prescription drugs; Healthcare Common Procedure Coding System J-codes were used to capture biologic out-patient infusions. Proportion of drug usage, relative market share and per-member per-year (PMPY) costs were analysed for biologics, immunomodulators, 5-ASAs and corticosteroids. RESULTS: In 415 405 patients (188 842 CD; 195 183 UC; 31 380 indeterminate colitis; 54.67% female), utilization trends show a consistent rise in the market share of biologics during the 9-year study period. The proportion of patients using biologics increased from 21.8% to 43.8% for CD and 5.1%-16.2% for UC. This contrasts a small decrease in immunomodulator and 5-ASA use for CD and relative constancy of other classes including corticosteroids-only use as primary IBD medication from 2007 to 2015. The average biologic-taking patient accounted for $25 275 PMPY in 2007 and $36 051 PMPY in 2015. The average paediatric biologic-taking patient accounted for $23 616 PMPY in 2007 and $41 109 PMPY in 2015. In all patients, the share of costs for biologics increased from 72.9% in 2007 to 85.7% in 2015 (81.7% in 2007 to 94.9% in 2015 in paediatrics). CONCLUSION: The vast majority of costs allocated to out-patient IBD medications in the USA is attributed to increasing use of biologic therapies despite the relative minority of biologic-taking patients.

Extracellular vesicles (EVs), including exosomes, are promising circulating biomarkers for disease diagnosis. Conventional EVs analysis requires multiple instrumentations to obtain their phenotypic features, which limits its wide applications. Here, we present a plasmonic biosensor technology for multifunctional analysis of EVs. The system is based on a functionalized surface plasmon resonance (SPR) biosensor and an advanced plasmonic microscopy to capture and image EVs at single-particle level. SPR images are processed with a home-developed deep learning algorithm to identify EVs and quantify image intensity automatically. By combining immunosensing and single particle analysis, this approach enables both physical and chemical characterization of EVs. As a proof-of-concept, we applied it to analyze EVs secreted from human lung cancer A549 cell lines. Results show the capabilities in the detection of size, concentration and affinity constant. Due to the single particle imaging and multifunctional analysis capability, we anticipate that this technology will find use in clinical and scientific applications.