Passive Observations of a Large DNS Service:2.5 Years in the Life of Google

In 2009 Google launched its Public DNS service, with its characteristic IP address 8.8.8.8. Since then, this service has grown to be the largest and most well-known DNS service in existence. The popularity of public DNS services has been disruptive for Content Delivery Networks (CDNs). CDNs rely on IP information to geo-Iocate clients. This no longer works in the presence of public resolvers, which led to the introduction of the EDNSO Client Subnet extension. ECS allows resolvers to reveal part of a client's IP address to authoritative name servers and helps CDNs pinpoint client origin. A useful side effect of ECS is that it can be used to study the workings of public DNS resolvers. In this paper, we leverage this side effect of ECS to study Google Public DNS. From a dataset of 3.7 billion DNS queries spanning 2.5 years, we extract ECS information and perform a longitudinal analysis of which clients are served from which Point-of-Presence. Our study focuses on two aspects of GPDNS. First, we show that while GPDNS has PoPs in many countries, traffic is frequently routed out of country, even if that was not necessary. Often this reduces performance, and perhaps more importantly, exposes DNS requests to state-level surveillance. Second, we study how GPDNS is used by clients. We show that end-users switch to GPDNS en masse when their ISP's DNS service is unresponsive, and do not switch back. We also find that many e-mail providers configure GPDNS as the resolver for their servers. This raises serious privacy concerns, as DNS queries from mail servers reveal information about hosts they exchange mail with. Because of GPDNS's use of ECS, this sensitive information is not only revealed to Google, but also to any operator of an authoritative name server that receives ECS-enabled queries from GPDNS during the lookup process

Accelerometer Measured Sedentary and Physical Activity Behaviors of Working Patients after Total Knee Arthroplasty, and their Compensation Between Occupational and Leisure Time

Purpose Objective measurements of sedentary and physical activity (PA) behavior are scarce among working-age patients who undergo total knee arthroplasty (TKA). Aim was to assess sedentary and PA behaviors using accelerometers and to identify compensation effects between occupational and leisure time of sedentary and PA behavior. Methods One year post-TKA, 51 patients wore an ActiGraph(GT3x) accelerometer for 7 days. Sedentary time, prolonged sedentary bouts (≥ 30 min) and PA (light-intensity and moderate-to-vigorous PA) were examined. Compliance with the guideline of > 150 min moderate-to-vigorous PA per week was calculated. Compensation effects were analyzed using multilevel models, splitting effects into routine and within-day compensation, stratifying by physical and non-physical jobs. The routine compensation effects are the ones of interest, representing habitual compensation during a week. Results Participants spent 60% of time in sedentary bouts and 17% in prolonged sedentary bouts, with 37% of PA spent in light-intensity and 3% in moderate-to-vigorous activity. About 70% of patients met the PA guideline. Routine compensation effects were found for workers in physical jobs, who compensated for their occupational light-intensity PA with less light-intensity PA during leisure time. Workers in non-physical jobs did not compensate for their occupational prolonged sedentary bouts, as these continued during leisure time. Conclusion This study showed that working TKA patients are highly sedentary 1 year after surgery, but most met the PA guideline. Especially those with non-physical jobs do not compensate for their occupational prolonged sedentary bouts. This stresses the need to stimulate PA among TKA patients not complying with the guidelines and those with non-physical jobs

The USP7-TRIM27 axis mediates non-canonical PRC1.1 function and is a druggable target in leukemia

In an attempt to unravel functionality of the non-canonical PRC1.1 Polycomb complex in human leukemogenesis, we show that USP7 and TRIM27 are integral components of PRC1.1. USP7 interactome analyses show that PRC1.1 is the predominant Polycomb complex co-precipitating with USP7. USP7 inhibition results in PRC1.1 disassembly and loss of chromatin binding, coinciding with reduced H2AK119ub and H3K27ac levels and diminished gene transcription of active PRC1.1-controlled loci, whereas H2AK119ub marks are also lost at PRC1 loci. TRIM27 and USP7 are reciprocally required for incorporation into PRC1.1, and TRIM27 knockdown partially rescues USP7 inhibitor sensitivity. USP7 inhibitors effectively impair proliferation in AML cells in vitro, also independent of the USP7-MDM2-TP53 axis, and MLL-AF9-induced leukemia is delayed in vivo in human leukemia xenografts. We propose a model where USP7 counteracts TRIM27 E3 ligase activity, thereby maintaining PRC1.1 integrity and function. Moreover, USP7 inhibition may be a promising new strategy to treat AML patients

Late-transition-state metal catalyzed polymerizations of olefins in supercritical carbon dioxide

+124hlm.;24c

Broad and load-aware anycast mapping with Verfploeter

IP anycast provides DNS operators and CDNs with automatic failover and reduced latency by breaking the Internet into catchments, each served by a different anycast site. Unfortunately understanding and predicting changes to catchments as anycast sites are added or removed has been challenging. Current tools such as RIPE Atlas or commercial equivalents map from thousands of vantage points (VPs), but their coverage can be inconsistent around the globe. This paper proposes Verfploeter, a new method that maps anycast catchments using active probing. Verfploeter provides around 3.8M passive VPs, 430× the 9k physical VPs in RIPE Atlas, providing coverage of the vast majority of networks around the globe. We then add load information from prior service logs to provide calibrated predictions of anycast changes. Verfploeter has been used to evaluate the new anycast deployment for B-Root, and we also report its use of a nine-site anycast testbed. We show that the greater coverage made possible by Verfploeter's active probing is necessary to see routing differences in regions that have sparse coverage from RIPE Atlas, like South America and China

Integration of Inverse Supercritical Fluid Extraction and Miniaturized Asymmetrical Flow Field-Flow Fractionation for the Rapid Analysis of Nanoparticles in Sunscreens

We report the use of inverse supercritical fluid extraction (SFE) and miniaturized asymmetrical flow field-flow fractionation (mAF4) for the preparation and subsequent analysis of titanium dioxide nanoparticles in model and commercial sunscreens. The approach allows for the fast and reliable fractionation and sizing of TiO2nanoparticles and their quantitation in commercial products. This new method represents a powerful and efficient tool for the verification of nanoparticle content in a wide range of matrixes, as demanded by recently introduced regulatory requirements. Furthermore, the use of carbon dioxide as an environmentally friendly solvent is in line with the increasing need for ecologically compatible analytical techniques

Inverse supercritical fluid extraction as a sample preparation method for the analysis of the nanoparticle content in sunscreen agents

We demonstrate the use of inverse supercritical carbon dioxide (scCO2) extraction as a novel methodof sample preparation for the analysis of complex nanoparticle-containing samples, in our case a modelsunscreen agent with titanium dioxide nanoparticles. The sample was prepared for analysis in a simplifiedprocess using a lab scale supercritical fluid extraction system. The residual material was easily dispersedin an aqueous solution and analyzed by Asymmetrical Flow Field-Flow Fractionation (AF4) hyphenatedwith UV- and Multi-Angle Light Scattering detection. The obtained results allowed an unambiguousdetermination of the presence of nanoparticles within the sample, with almost no background fromthe matrix itself, and showed that the size distribution of the nanoparticles is essentially maintained.These results are especially relevant in view of recently introduced regulatory requirements concerningthe labeling of nanoparticle-containing products. The novel sample preparation method is potentiallyapplicable to commercial sunscreens or other emulsion-based cosmetic products and has importantecological advantages over currently used sample preparation techniques involving organic solvents.JRC.I.4-Nanobioscience