Ethics, politics and migration: Public debates on the free movement of Romanians and Bulgarians in the UK, 2006–2013

Public debates on immigration have become the subject of much concern, particularly in the UK. This article applies an ethical lens to assess changes in public debates over intra-EU migration in six UK national newspapers during 2006 and 2013. It finds an almost complete dominance of communitarian justifications, mainly based on welfare chauvinism, but a notable increase in security-related arguments and a decrease in economic nationalist ideas. Alternative cosmopolitan arguments about immigration go from rare to virtually absent. The discussion links these shifts to a failure of the UK centre-left to overcome historic difficulties in presenting a coherent narrative on immigration policy

Particles-vortex interactions and flow visualization in He4

Recent experiments have demonstrated a remarkable progress in implementing and use of the Particle Image Velocimetry (PIV) and particle tracking techniques for the study of turbulence in He4. However, an interpretation of the experimental data in the superfluid phase requires understanding how the motion of tracer particles is affected by the two components, the viscous normal fluid and the inviscid superfluid. Of a particular importance is the problem of particle interactions with quantized vortex lines which may not only strongly affect the particle motion, but, under certain conditions, may even trap particles on quantized vortex cores. The article reviews recent theoretical, numerical, and experimental results in this rapidly developing area of research, putting critically together recent results, and solving apparent inconsistencies. Also discussed is a closely related technique of detection of quantized vortices negative ion bubbles in He4.Comment: To appear in the J Low Temperature Physic

Taxonomy and physiology of rhizobia

Rhizobia are common Gram-negative soil-inhabiting bacteria distinguished by the feature that they contain genes required for nodulation (e.g. nod, rhi) and ni¬trogen fixation (e.g. nif, fix). These genes enable them to form a symbiotic asso¬ciation with legumes. Currently there are 15 genera of root nodule bacteria (Ta¬ble 7.1) containing more than 120 described species