181 research outputs found

    Tensor gauge fields in arbitrary representations of GL(D,R): II. Quadratic actions

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    Quadratic, second-order, non-local actions for tensor gauge fields transforming in arbitrary irreducible representations of the general linear group in D-dimensional Minkowski space are explicitly written in a compact form by making use of Levi-Civita tensors. The field equations derived from these actions ensure the propagation of the correct massless physical degrees of freedom and are shown to be equivalent to non-Lagrangian local field equations proposed previously. Moreover, these actions allow a frame-like reformulation a la MacDowell-Mansouri, without any trace constraint in the tangent indices.Comment: LaTeX, 53 pages, no figure. Accepted for publication in Communications in Mathematical Physics. Local Fierz-Pauli programme achieved by completing the analysis of Labastid

    Serologic Survey of Hantavirus Infection, Brazilian Amazon

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    Federal University of MaranhĂŁo. SĂŁo LuĂ­s, MA, Brazil.Federal University of MaranhĂŁo. SĂŁo LuĂ­s, MA, Brazil.Federal University of MaranhĂŁo. SĂŁo LuĂ­s, MA, Brazil.Federal University of MaranhĂŁo. SĂŁo LuĂ­s, MA, Brazil.Federal University of MaranhĂŁo. SĂŁo LuĂ­s, MA, Brazil.Federal University of MaranhĂŁo. SĂŁo LuĂ­s, MA, Brazil.State Department of Health. SĂŁo LuĂ­s, MA, Brazil.MinistĂ©rio da SaĂșde. Secretaria de VigilĂąncia em SaĂșde. Instituto Evandro Chagas. BelĂ©m, PA, Brasil.MinistĂ©rio da SaĂșde. Secretaria de VigilĂąncia em SaĂșde. Instituto Evandro Chagas. BelĂ©m, PA, Brasil

    Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

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    We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

    AVASUS’ Contributions to Promoting Lifelong Learning in Health: Toward Achieving the SDGs and Strengthening Global Health Security

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    The Virtual Learning Environment of the Brazilian Health System (AVASUS) was developed by the Laboratory for Technological Innovation in Health (LAIS) and the Secretariat of Distance Education (SEDIS) at the Federal University of Rio Grande do Norte (UFRN) in partnership with Brazil’s Ministry of Health (MoH). AVASUS provides open educational resources in the health field and has emerged as the third largest platform for massive health education globally, with more than one million students. Among the various learning pathways AVASUS offers, some specifically focus on meeting the educational needs to address public health emergencies and overlooked health contexts. The main argument in this study is that technology-mediated lifelong learning in health is an effective strategy for achieving the Sustainable Development Goals (SDGs) of the 2030 Agenda. This chapter analyzes the pathways related to COVID-19, syphilis, and prison health, focusing on the contributions towards achieving SDGs 3, 4, 5, 10, 11, 16, and 17 and fulfilling the Global Health Security Agenda. Our analysis revealed two key findings. Lifelong learning in health (i) prompts decision-making on public health policies and (ii) contributes towards implementing the SDGs. Ultimately, AVASUS should be recognized as a tool to improve health services and support policy-making

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
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