The Hierarchy of Excitation Lifetimes in Two-Dimensional Fermi Gases

Momentum-conserving quasiparticle collisions in two-dimensional Fermi gases give rise to a large family of exceptionally long-lived excitation modes. The lifetimes of these modes exceed by a factor $(T_F/T)^2\gg 1$ the conventional Landau Fermi-liquid lifetimes $\tau\sim T_F/T^2$. The long-lived modes have a distinct angular structure, taking the form of $\cos m\theta$ and $\sin m\theta$ with odd $m$ values for a circular Fermi surface, with relaxation rate dependence on $m$ of the form $m^4\log m$, valid at not-too-large $m$. In contrast, the even-$m$ harmonics feature conventional lifetimes with a weak $m$ dependence. The long-time dynamics, governed by the long-lived modes, takes the form of angular (super)diffusion over the Fermi surface. Altogether, this leads to unusual long-time memory effects, defining an intriguing transport regime that lies between the conventional ballistic and hydrodynamic regimes.Comment: 29 pgs, 6 fg

Topological phase transitions and quantum Hall effect in the graphene family

Monolayer staggered materials of the graphene family present intrinsic spin-orbit coupling and can be driven through several topological phase transitions using external circularly polarized lasers and static electric or magnetic fields. We show how topological features arising from photoinduced phase transitions and the magnetic-field-induced quantum Hall effect coexist in these materials and simultaneously impact their Hall conductivity through their corresponding charge Chern numbers. We also show that the spectral response of the longitudinal conductivity contains signatures of the various phase-transition boundaries, that the transverse conductivity encodes information about the topology of the band structure, and that both present resonant peaks which can be unequivocally associated with one of the four inequivalent Dirac cones present in these materials. This complex optoelectronic response can be probed with straightforward Faraday rotation experiments, allowing the study of the crossroads between quantum Hall physics, spintronics, and valleytronics

Scientific advice on the suitability of data for the assessment of DNA integration into the fish genome of a genetically modified DNA plasmid-based veterinary vaccine

Pancreas disease caused by salmonid alphavirus in farmed Atlantic salmon (Salmo salar) leads to high mortality rates post infection and histopathological lesions in several organs. As protection against pancreas disease, Novartis developed a prophylactic DNA plasmid-based vaccine to be administered to salmon as naked plasmid in a single intramuscular injection. In order to assess the legal status of the fish vaccinated with this new vaccine with regard to the legislation on genetically modified organisms, the European Commission suggested that the company carry out a scientific study on the integration/non-integration of the plasmid DNA into the fish genome. Subsequently, the European Commission requested EFSA to give scientific advice on the study design and the conclusions drawn by the company. PCR based analysis of genomic DNA from muscle samples, taken from at or around the injection site 436 days post vaccination, led the company to conclude that integration of plasmid DNA into the fish genome is extremely unlikely. After an assessment of the study, EFSA considers that the study presented by Novartis Animal Health on the integration/non-integration of DNA plasmid-based vaccine into the salmon genomic DNA provides insufficient information on the potential integration of plasmid DNA fragments into the fish genome due to a limited coverage of the plasmid DNA by the detection method provided, the limited number of samples analysed and an insufficient limit of detection and method validation. Therefore, EFSA is of the opinion that the results from the integration/non-integration study submitted by Novartis Animal Health are not sufficient to support the conclusion of non-integration of plasmid DNA into the fish genome drawn by the company

Vive la différence? Women and trade unions in Britain

Dans tous les domaines, et particulièrement dans celui de l’engagement syndical, les femmes sont à la fois semblables à, et différentes des hommes. Dans une analyse en termes de lutte des classes, les femmes comme les hommes sont opprimés par le capital sous différentes formes et espèrent s’unir contre cette oppression. Cependant, selon une analyse en termes de rapport patriarcal, les femmes sont opprimées par les hommes quelle que soit leur place dans la structure sociale. Cette différence fondamentale ouvre des perspectives intéressantes et sous-tend le débat engagé ici sur les femmes et la politique du genre au sein des syndicats britanniques. Cet article vise à étudier les tensions et les paradoxes concernant le rôle des femmes dans les syndicats et à montrer comment les pratiques discriminatoires à l’encontre des femmes sur le lieu de travail et dans le mouvement syndical ont influencé le syndicalisme britannique depuis la révolution industrielle.In all respects, and especially in the field being discussed in this issue on British trade unions, women are both similar to, and different from men. In a class analysis working women and men are each oppressed by capital in its various forms, with the expectation that they will both collectivise against this oppression. However in a patriarchal analysis women are oppressed by men wherever they sit in the class structure. This fundamental difference leads in interesting directions, and informs the discussion in this article about women and gender politics in British trade unions. This article aims to explore the tensions and paradoxes about the role of women in trade unions, discuss how exclusionary practices against women in the workplace and in trade unions have shaped their trade unionism over the 200 years since industrialisation in Britain

Application of Absorbing Markov Chains to the Assessment of Education Attainment Rates within Air Force Materiel Command Civilian Personnel

Increasing the education levels of an organization is a common response when attempting to improve organizational performance; however, organizational performance improvements are seldom found when the current and future workforce education levels are unknown. In this research, absorbing Markov chains are used to probabilistically forecast the educational composition of the Air Force Materiel Command civilian workforce to enable organizational performance improvements. Through the purposeful decoupling of effects resulting from recent workforce arrivals and education level progressions, this research attempts to determine the implications that stationarity assumptions have throughout the model development process of an absorbing Markov chain. The results of the analysis indicate that the four combinations of stationarity assumptions perform similarly at representing the historical data and that the forecasted educational attainment rates of the Air Force Materiel Command civilian workforce are expected to increase significantly