In-Depth Technical and Legal Analysis of Tracking on Health Related Websites with ERNIE Extension

Searching the Web to find doctors and make appointments online is a common practice nowadays. However, simply visiting a doctors website might disclose health related information. As the GDPR only allows processing of health data with explicit user consent, health related websites must ask consent before any data processing, in particular when they embed third party trackers.Admittedly, it is very hard for owners of such websites to both detect the complex tracking practices that exist today and to ensure legal compliance. In this paper, we present ERNIE, a browser extension we designed to visualise six state-of-the-art tracking techniques based on cookies. Using ERNIE, we analysed 385 health related websites that users would visit when searching for doctors in Germany, Austria, France, Belgium, and Ireland. More specifically, we explored the tracking behavior before any interaction with the consent pop-up and after rejection of cookies on websites of doctors, hospitals, and health related online phone-books. We found that at least one form of tracking occurs on 62% of the websites before interacting with the consent pop-up, and 15% of websites include tracking after rejection. Finally, we performed a detailed technical and legal analysis of three health related websites that demonstrate impactful legal violations. This paper shows that while, from a legal point of view, health related websites are more privacy-sensitive than other kinds of websites, they are exposed to the same technical difficulties to implement a legally compliant website. We believe ERNIE, the browser extension we developed, to be an invaluable tool for policy-makers and regulators to improve detection and visualization of the complex tracking techniques used on these websites

Hyper-parameter optimization tools comparison for Multiple Object Tracking applications

International audienceCommonly, when developing an algorithm it is necessary to define a certain number of variables that control its behavior. Optimal parameters result in better performance that could translate into profits for companies, stand out among similar applications or better ranking on algorithm competitions. However, it is not a simple task to find the combination of parameters that provides the best results. Manual tuning could be a stressful and difficult task even for expert users. In this paper we present, evaluate and compare several tools in the literature for hyper-parameter optimization. We focus on 4 tools that have been selected due to their number of citations, code availability and impact on literature: MCMC, SMAC, TPE and Spearmint. We analyze these tools in the context of Multi Object Tracking (MOT) that have not been well studied in the literature. MOT itself has been well-studied topic with multiple parameters to be tuned. We evaluate these tools using public benchmarks such as PETS09 or ETH and using the publicly available source code provided by the authors. We analyze the impact of these tools in terms of stability, performance, and usabil-ity, among others. Our results show how the use of these tools change the performance of the application and how this would affect the results of real ranked competitions. Our goal is (1) to encourage the reader to use these tools and (2) to provide a guide that helps to choose the most pertinent tool

PSGL-1–mediated activation of EphB4 increases the proangiogenic potential of endothelial progenitor cells

Endothelial progenitor cell (EPC) transplantation has beneficial effects for therapeutic neovascularization; however, only a small proportion of injected cells home to the lesion and incorporate into the neocapillaries. Consequently, this type of cell therapy requires substantial improvement to be of clinical value. Erythropoietin-producing human hepatocellular carcinoma (Eph) receptors and their ephrin ligands are key regulators of vascular development. We postulated that activation of the EphB4/ephrin-B2 system may enhance EPC proangiogenic potential. In this report, we demonstrate in a nude mouse model of hind limb ischemia that EphB4 activation with an ephrin-B2–Fc chimeric protein increases the angiogenic potential of human EPCs. This effect was abolished by EphB4 siRNA, confirming that it is mediated by EphB4. EphB4 activation enhanced P selectin glycoprotein ligand-1 (PSGL-1) expression and EPC adhesion. Inhibition of PSGL-1 by siRNA reversed the proangiogenic and adhesive effects of EphB4 activation. Moreover, neutralizing antibodies to E selectin and P selectin blocked ephrin-B2–Fc–stimulated EPC adhesion properties. Thus, activation of EphB4 enhances EPC proangiogenic capacity through induction of PSGL-1 expression and adhesion to E selectin and P selectin. Therefore, activation of EphB4 is an innovative and potentially valuable therapeutic strategy for improving the recruitment of EPCs to sites of neovascularization and thereby the efficiency of cell-based proangiogenic therapy