On multi-exit routings and AS relationships

International audienc

Latency-Based Anycast Geolocation: Algorithms, Software, and Datasets

International audienceUse of IP-layer anycast has increased in the last few years beyond the DNS realm. Yet, existing measurement techniques to identify and enumerate anycast replicas exploit specifics of the DNS protocol, which limits their applicability to this particular service. With this paper, we not only propose and thoroughly validate a protocol-agnostic technique for anycast replicas discovery and geolocation, but also provide the community with open source software and datasets to replicate our experimental results, as well as facilitating the development of new techniques such as ours. In particular, our proposed method achieves thorough enumer-ation and city-level geolocalization of anycast instances from a set of known vantage points. The algorithm features an iterative workflow, pipelining enumeration (an optimization problem using latency as input) and geolocalization (a classification problem using side channel information such as city population) of anycast replicas. Results of a thorough validation campaign show our algorithm to be robust to measurement noise, and very lightweight as it requires only a handful of latency measurements

High sensitivity detection of nanoparticles permeation through polymer membranes: A physico-chemical and nuclear imaging measurement approach

Diffusion cells are devices made of donor and acceptor compartments (DC and AC), separated by a membrane. They are widely used in pharmaceutical, cosmetic, toxicology, and protective equipment tests (e.g., gloves) to measure the kinetics of permeants (molecules and nanoparticles) across biological membranes as the skin. However, rarely is the concentration of permeants in the AC measured in continuous or in real-time, and this limitation leads to significant discrepancies in the calculations of kinetic parameters that define the permeation mechanisms. In this study, a diffusion cell compatible with positron emission tomography was used to measure the permeation kinetics of nanoparticles across glove membranes. The technology allows for the measurement of nanoparticle concentration in real-time in the two compartments (DC and AC) and at a detection sensitivity several orders of magnitude higher compared with conventional spectroscopies, thus allowing a much more precise extraction of kinetic parameters. Ultra-small (<10 nm) gold nanoparticles were used as a model nanoparticle contaminant. They were radiolabeled, and their diffusion kinetics was measured in continuous through latex and nitrile polymer membranes. Permeation profiles were recorded at sub-nanomolar sensitivity and in real-time, thus allowing the high precision extraction of kinetic permeation parameters. The technology, methodology, and data extraction process developed in this work could be applied to measure in real-time the kinetics of diffusion of a whole range of potentially toxic molecules and nanoparticles across polymer membranes, including glove membranes

Contemporary Photographic Practices on the British Fairground

The fairground is a somewhat magical and uncharted realm of illusion, deception, thrill and adventure. It offers a glimpse of the improbable and impossible, and a taste or touch of the unattainable. This article looks at the crossover of photography and the British fairground following the gradual take-up of photography in the post-war period. It briefly covers early traditions concomitant with the specialised practice of photography, then it identifies photographic practices on the fairground through distinct communities of engagement including professional and amateur photographers attracted to the spectacle of the fair, ethnographic explorers, dedicated enthusiasts, showpeople and the general public of “punters”. In each case photographs from these communities are presented as well as a selection of photographs depicting these communities of photographers in action. The article concludes with the current situation of camera phone technology, social media and digitally manipulated photographic art as a new aesthetic of the fairground

Non -Places. : Introduction to an Anthropology of Supermodernity.

New York122 p, 21 cm

Les lacertiliens (Reptilia, Squamata) de l'Eocene superieur et de l'Oligocene ouest europeens

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Tradition et conservatisme. Essai de lecture d'un terroir. Pays Alladian Basse (Côte-d'Ivoire)

Auge Marc. Tradition et conservatisme. Essai de lecture d'un terroir. Pays Alladian Basse (Côte-d'Ivoire). In: Études rurales, n°37-39, 1970. pp. 281-298