Bubble kinematics in a sheared foam

We characterize the kinematics of bubbles in a sheared two-dimensional foam using statistical measures. We consider the distributions of both bubble velocities and displacements. The results are discussed in the context of the expected behavior for a thermal system and simulations of the bubble model. There is general agreement between the experiments and the simulation, but notable differences in the velocity distributions point to interesting elements of the sheared foam not captured by prevalent models

Elastic turbulence in shear banding wormlike micelles

We study the dynamics of the Taylor-Couette flow of shear banding wormlike micelles. We focus on the high shear rate branch of the flow curve and show that for sufficiently high Weissenberg numbers, this branch becomes unstable. This instability is strongly sub-critical and is associated with a shear stress jump. We find that this increase of the flow resistance is related to the nucleation of turbulence. The flow pattern shows similarities with the elastic turbulence, so far only observed for polymer solutions. The unstable character of this branch led us to propose a scenario that could account for the recent observations of Taylor-like vortices during the shear banding flow of wormlike micelles

Thermal Comptonization in Mildly Relativistic Pair Plasmas

We use a Monte Carlo simulation to calculate the spectra of mildly relativistic thermal plasmas in pair balance. We use the exact integral expression for the electron-positron thermal annihilation spectrum, and provide accurate expressions for the Gaunt factors of electron-ion, electron-electron, and electron-positron thermal bremsstrahlung in the transrelativistic temperature regime. The particles are assumed to be uniformly distributed throughout a sphere, and the pair opacity is self-consistently calculated from the energy and angular distribution of scattered photons. The resultant photon spectra are compared with the nonrelativistic diffusion treatment of Sunyaev and Titarchuk, the bridging formulas of Zdziarski, and the relativistic corrections proposed by Titarchuk. We calculate allowed pair-balanced states of thermal plasmas with no pair escape which include bremsstrahlung and internal soft photons. The results are presented in the spectral index/compactness plane, and can be directly compared with observations of spectra from AGNs and Galactic black hole candidates. By comparing with X-ray spectral indices of Seyfert AGNs and compactnesses inferred from X-ray variability data, we find that the allowed solutions for pair equilibrium plasma imply that the temperatures of Seyfert galaxies are $\lesssim 300$ keV. This prediction can be tested with more sensitive gamma-ray observations of Seyfert galaxies. We find that if the X-ray variability time scale gives an accurate measure of the compactness, pair-dominated solutions are inconsistent with the data.Comment: 32 pages with 9 figures, compressed and uuencoded postscrip

The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods

A recent workshop entitled The Family Name as Socio-Cultural Feature and Genetic Metaphor: From Concepts to Methods was held in Paris in December 2010, sponsored by the French National Centre for Scientific Research (CNRS) and by the journal Human Biology. This workshop was intended to foster a debate on questions related to the family names and to compare different multidisciplinary approaches involving geneticists, historians, geographers, sociologists and social anthropologists. This collective paper presents a collection of selected communications

Fingerprinting Soft Materials: A Framework for Characterizing Nonlinear Viscoelasticity

We introduce a comprehensive scheme to physically quantify both viscous and elastic rheological nonlinearities simultaneously, using an imposed large amplitude oscillatory shear (LAOS) strain. The new framework naturally lends a physical interpretation to commonly reported Fourier coefficients of the nonlinear stress response. Additionally, we address the ambiguities inherent in the standard definitions of viscoelastic moduli when extended into the nonlinear regime, and define new measures which reveal behavior that is obscured by conventional techniques.Comment: 10 pages, 3 figures, full-page double-space preprint forma

What is the nature and extent of evidence on methodologies for monitoring and evaluating marine spatial management measures in UK and similar coastal waters? A systematic map protocol

Background Anthropogenic degradation of marine ecosystems is widely accepted as a major social-ecological problem. The growing urgency to better manage marine ecosystems has led to the increasing application of ‘spatial management measures’ including marine protected areas, sectoral (e.g. fishery) closures, and marine spatial planning. However, the designation of varied spatial management regimes is just the first step; achievement of objectives relies upon effective implementation, monitoring, evaluation and adaptation. Despite spatial management being a core component of the marine management portfolio, to our knowledge, there is no systematic overview of the evidence on methodologies available, and employed, to monitor and evaluate their effectiveness across social, economic and ecological outcomes. Methods This systematic map will examine existing evidence describing methodologies for monitoring the effects, and evaluating the effectiveness, of marine spatial management across ecological, social and economic outcomes. Our aim is to provide a resource for decision-makers, primarily in the UK but also internationally, that supports effective marine management, and to describe the current evidence base. Identification and evaluation of relevant studies will therefore be restricted to coastal countries identified by our Stakeholder Group as being relevant to the UK, and searches will be restricted to the period 2009 to 2019 to align with the current UK policy context. Searches for relevant grey and academic literature, published in English, will be conducted in four bibliographic search engines, Google Scholar, 38 organisational websites and one specialist data repository. Eligibility screening will be conducted first at title and abstract level, and then at full text. Coding and meta-data extraction from eligible studies will include: bibliographic information, general information about the spatial management measure studied, and methodological information on the monitoring and evaluation undertaken. Consistency checking amongst reviewers will be undertaken during screening, coding and data extraction phases. The outcome of the systematic map will be a database that displays the meta-data of identified relevant studies. Findings will be presented in a descriptive report detailing the evaluation approaches and analytical methodologies employed, and data collection methods applied and/or data required by relevant studies to inform evaluations on the effectiveness of marine spatial management measures

Impact of performance in a mandatory postgraduate surgical examination on selection into specialty training

Acknowledgements The authors acknowledge I. Targett from the Royal College of Surgeons of England for his help with data collection, and both L. Smith and G. Ayre from the Intercollegiate Committee for Basic Surgical Examinations for their support during this project. This study was funded by the Royal Colleges of Surgeons of England, Ireland and Edinburgh, and the Royal College of Physicians and Surgeons of Glasgow.Peer reviewedPublisher PD