Dynamics of localized spins coupled to the conduction electrons with charge/spin currents

The effects of the charge/spin currents of conduction electrons on the dynamics of the localized spins are studied in terms of the perturbation in the exchange coupling $J_{K}$ between them. The equations of motion for the localized spins are derived exactly up to $O(J_{K}^2)$, and the equations for the two-spin system is solved numerically. It is found that the dynamics depends sensitively upon the relative magnitude of the charge and spin currents, i.e., it shows steady state, periodic motion, and even chaotic behavior. Extension to the multi-spin system and its implications including possible ``spin current detector'' are also discussed.Comment: 5 pages, 4 figures, REVTe

Ideology and the limits of self-interest: System justification motivation and conservative advantages in mass politics

It is commonly assumed that political attitudes are driven by self-interest and that poor people heavily favor policies aimed at redistributing wealth. This assumption fails to explain the popularity of economic conservatism and the degree of support for the capitalist system. Such outcomes are typically explained by the suggestion that most poor people believe they will become rich one day. In a representative sample of low-income Americans, we observed that less than one-fourth were optimistic about their economic prospects. Those respondents who believed that they would become rich one day were no more likely to endorse the legitimacy of the system and no more supportive of conservative ideology or the Republican Party, compared to those who did not believe they would become rich. From a system justification perspective, we propose that people are motivated to defend the social systems on which they depend, and this confers a psychological advantage to conservative ideology. Providing ideological support for the status quo serves epistemic motives to reduce uncertainty, existential motives to reduce threat, and relational motives to share reality with members of mainstream society. We summarize evidence from the United States, Argentina, Lebanon, and other countries bearing on these propositions—including a survey administered shortly before the 2016 U.S. Presidential election—and discuss political implications of system justification motivation.Fil: Jost, John T.. University of New York; Estados UnidosFil: Langer, Melanie. University of New York; Estados UnidosFil: Badaan, Vivienne. University of New York; Estados UnidosFil: Azevedo, Flávio. Universitat Zu Köln; AlemaniaFil: Etchezahar, Edgardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro Interdisciplinario de Investigaciones en Psicología Matemática y Experimental Dr. Horacio J. A. Rimoldi; ArgentinaFil: Ungaretti, Joaquín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro Interdisciplinario de Investigaciones en Psicología Matemática y Experimental Dr. Horacio J. A. Rimoldi; ArgentinaFil: Hennes, Erin P.. Purdue University; Estados Unido

Are lip prints hereditary? A systematic review

Hereditary lip prints have been studied by several researchers. However, the literature shows no consensus among the scientific community regarding this topic. Therefore, the aim of this study was to conduct a systematic review to gather evidence to clarify whether the surface structure of lip prints is hereditary and, consequently, if a familial relationship between individuals can be established through the analysis of lip prints. The systematic review was performed following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. A bibliographic survey was conducted in PubMed, Scopus, and Web of Science databases, restricted to articles published between 2010 and 2020. Studies were selected according to eligibility criteria, and then the study data were collected. The risk of bias of each study was assessed and applied as additional inclusion or exclusion criteria. The results of the articles eligible for analysis were synthesized by a descriptive approach. In the seven included studies, methodological variations, including the definition of similarity, that contribute to the heterogeneity of results were identified. The data gathered allowed to conclude that there is no strong scientific evidence to support the hypothesis of the existence of heredity in the surface structure of lip prints, since it was not proven that similarities between parents and children occur systematically in all families.Open access funding provided by FCT|FCCN (b-on). The co-author Caldas IM was financed by the R&D Unit Centre for Functional Ecology-Science for People and the Planet (CFE), with reference UIDB/04004/2020, financed by FCT/MCTES through national funds (PIDDAC)

“Es mejor ser pobre aquí”: procesos de toma de decisiones sobre migración y consideraciones políticas y de estilo de vida entre brasileños calificados en Portugal

This article looks at the migration of qualified Brazilians to Portugal, with reference to the impact of political developments in Brazil on migration decision-making processes and their lifestyle aspirations in the host society. Original fieldwork consists of twenty in-depth interviews conducted with qualified Brazilians in the Lisbon area during 2019. These interviews illustrate how political and economic instability in Brazil contributed to establishing a strong migration imperative. In this scenario, Portugal is chosen as a destination due to its perceived social stability and emergence as a fashionable destination for skilled workers, with the promise of a “cosmopolitan” life. In conclusion, we emphasise the need to consider how political conditions in a sending society and lifestyle considerations interact in the migration decision-making of skilled migrants. This approach confronts assumptions that serve to disguise the precariousness of many Brazilian migrants in Portugal due to their relatively high skill levels and raising long-term concerns regarding the sustainability of lifestyle-oriented migration.info:eu-repo/semantics/publishedVersio

South-South education relations

While scholarly interest in South–South cooperation (SSC) has substantially grown over the past decade, South–South education relations have received only scant attention in the Anglophone academic literatures on SSC, international development and international and comparative education. This chapter adopts an historical and global approach to this topic in an effort to contribute to closing this research gap. The chapter unfolds as follows: the first section introduces the concepts of ‘the South’ and ‘South–South cooperation’, counter-posed with practices of ‘triangular collaboration’ and ‘best practice transfer’. On this basis, the second section conducts a critical review of existing South–South education cooperation literatures. Framed by these discussions, two case studies of contemporary South–South education relations are presented: the ¡Yo, Sí Puedo! (Sure, I Can!) global literacy campaign promoted by the governments of the Republic of Cuba and the Bolivarian Republic of Venezuela; and the education cooperation agenda of the so-called BRICS. The conclusion resumes the question of whether South–South education cooperation simply represents ‘best practice transfer’ or Third World solidarity for global transformation, while proposals for a future research agenda are developed.info:eu-repo/semantics/acceptedVersio

Charge pumping in magnetic tunnel junctions: Scattering theory

We study theoretically the charge transport pumped by magnetization dynamics through epitaxial FIF and FNIF magnetic tunnel junctions (F: Ferromagnet, I: Insulator, N: Normal metal). We predict a small but measurable DC pumping voltage under ferromagnetic resonance conditions for collinear magnetization configurations, which may change sign as function of barrier parameters. A much larger AC pumping voltage is expected when the magnetizations are at right angles. Quantum size effects are predicted for an FNIF structure as a function of the normal layer thickness.Comment: 4 pages, 3 figures. to be published on Physical Review B Rapid Communicatio