In plane reorientation induced single laser pulse magnetization reversal in rare-earth based multilayer

Single Pulse All Optical Helicity Independent Switching (AO-HIS) represents the ability to reverse the magnetic moment of a nanostructure using a femtosecond single laser pulse. It is an ultrafast method to manipulate magnetization without the use of any applied field. Since the first switching experiments carried on GdFeCo ferrimagnetic systems, single pulse AO-HIS has been restricted for a while to Gd-based alloys or Gd/FM bilayers where FM is a ferromagnetic layer. Only recently has AO-HIS been extended to a few other materials: MnRuGa ferrimagnetic Heusler alloys and Tb/Co multilayers with a very specific range of thickness and composition. Here, we demonstrate that single pulse AO-HIS observed in Tb/Co results from a different mechanism than the one for Gd based samples and that it can be obtained for a large range of rare earth-transition metal (RE-TM) multilayers, making this phenomenon much more general. Surprisingly, in this large family of (RE-TM) multilayer systems, the threshold fluence for switching is observed to be independent of the pulse duration, up to at least 12 ps. Moreover, at high laser intensities, concentric ring domain structures are induced, unveiling multiple fluence thresholds. These striking switching features, which are in contrast to those of AO-HIS in GdFeCo alloys, concomitant with the demonstration of an in-plane reorientation of the magnetization, point towards an intrinsic precessional reversal mechanism. Our results allow expanding the variety of materials with tunable magnetic properties that can be integrated in complex heterostructures and provide a pathway to engineer materials for future applications based on all-optical control of magnetic order

Paleografía humana durante el Tardiglaciar y Holoceno inicial en el ámbito mediterráneo del Ne ibérico

En el NE mediterráneo de la Península Ibérica, el perído comprendido entre el Tardiglaciar y el Holoceno muestra una dinámica demográfica y cultural en la que se alternan momentos de abundancia de registro y diversidad de evidencias con fases de escasez y casos aislados. Los tecno-complejos microlaminares, que se inician durante el GI-1, rompen con el vacío del Pleniglaciar y parecen perdurar en el tiempo de forma discontinua hasta los inicios del Holoceno. Este hecho genera un escenario de convergencia cronológica con las escasas evidencias sauveterrienses y el Mesolítico de muescas y denticulados. Ambos aparecen en el registro coincidiendo con el tránsito Pleistoceno-Holoceno. La perduración de los conjuntos atribuídos al Paleolítico superior final rompe con la homgeneidad cronológica del proceso observada en los territorios cercanos, mostrando las peculiaridades de la ocupación en un territorio concreto dentro de la evolución cultural de la Cuenca del Ebro y el Levante mediterráne

Internal delensing of cosmic microwave background polarization B-Modes with the POLARBEAR experiment

International audienceUsing only cosmic microwave background polarization data from the polarbear experiment, we measure B-mode polarization delensing on subdegree scales at more than 5σ significance. We achieve a 14% B-mode power variance reduction, the highest to date for internal delensing, and improve this result to 22% by applying for the first time an iterative maximum a posteriori delensing method. Our analysis demonstrates the capability of internal delensing as a means of improving constraints on inflationary models, paving the way for the optimal analysis of next-generation primordial B-mode experiments

How is the economic crisis socially assessed?

Based on the Social Representation Theory, the purpose of this article is to explore how lay-people consider both the economic crisis and risk, and to link these social representations to behavior. The article offers an original approach with the articulation of two studies about the social construction of risk and crises. It also contributes to the development of research methods for studying the connections between representations and practical implications. Based on this, the impact of the social representation of the crisis on the perceived ability to act is approached. The first study focuses on free-association tasks, with two distinct target terms: ‘risk’ and ‘crisis’. The structural approach, with a prototypical analysis, allowed the identification of two different representations: (1) for risk, ‘danger’ is the central element; (2) for crisis, ‘economy’ and ‘money’ constitute the main components of the representation. The second study investigates the links between the two previously detected structures and their relations with the perceived ability to act in a financial crisis context. Some aspects of social knowledge were found to have an impact on perceived ability to act

Critérios de construção e relato da análise prototípica para representações sociais

A análise prototípica é uma convenção de apresentação bastante difundida para caracterizar a estrutura de uma representação social a partir de dados de evocações livres. O presente texto visa a sistematizar e indicar algumas dessas informações que deveriam estar presentes na descrição de resultados da análise prototípica, discutindo brevemente os prós e contras de algumas opções de realização da análise. Para tanto, é feita uma breve introdução da análise e posteriormente passa-se a considerações técnicas, finalizando com um exemplo de relato

Personal model-assisted identification of NAD(+) and glutathione metabolism as intervention target in NAFLD

To elucidate the molecular mechanisms underlying non-alcoholic fatty liver disease (NAFLD), we recruited 86 subjects with varying degrees of hepatic steatosis (HS). We obtained experimental data on lipoprotein fluxes and used these individual measurements as personalized constraints of a hepatocyte genome-scale metabolic model to investigate metabolic differences in liver, taking into account its interactions with other tissues. Our systems level analysis predicted an altered demand for NAD(+) and glutathione (GSH) in subjects with high HS. Our analysis and metabolomic measurements showed that plasma levels of glycine, serine, and associated metabolites are negatively correlated with HS, suggesting that these GSH metabolism precursors might be limiting. Quantification of the hepatic expression levels of the associated enzymes further pointed to altered de novo GSH synthesis. To assess the effect of GSH and NAD(+) repletion on the development of NAFLD, we added precursors for GSH and NAD(+) biosynthesis to the Western diet and demonstrated that supplementation prevents HS in mice. In a proof-of-concept human study, we found improved liver function and decreased HS after supplementation with serine (a precursor to glycine) and hereby propose a strategy for NAFLD treatment.Peer reviewe

Covid-19 as a breakdown in the texture of social practices

A lot of things need to be repaired and a lot of relationships are in need of a knowledgeable mending. Can we start to talk/write about them? This invitation - sent by one of the authors to the others - led us, as feminist women in academia, to join together in an experimental writing about the effects of COVID-19 on daily social practices and on potential (and innovative) ways for repairing work in different fields of social organization. By diffractively intertwining our embodied experiences of becoming together-with Others, we foreground a multiplicity of repair (care) practices COVID-19 is making visible. Echoing one another, we take a stand and say that we need to prevent the future from becoming the past. We are not going back to the past; our society has already changed and there is a need to cope with innovation and repairing practices that do not reproduce the past.Funding Agencies|European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programmeEuropean Research Council (ERC) [715950]</p