Structure and Evolution of Low-Mass Stars: An Overview and Some Open Problems

A review is presented of some of the ingredients, assumptions and techniques that are used in the computation of the structure and evolution of low-mass stars. Emphasis is placed on several ingredients which are still subject to considerable uncertainty. An overview of the evolution of low-mass stars is also presented, from the cloud collapse phase all the way to the white dwarf cooling curve.Comment: 52 pages, 6 figures. Invited review, to appear in "XIth Special Courses at the National Observatory of Rio de Janeiro" (AIP Conf. Proc.), ed. J. Alcaniz, R. de la Reza, F. Roig, & D. F. Lope

Altmetrics : complexities, challenges and new forms of measurement and understanding of scientific communication in the social web

Objetivo. Tem como objetivo debater alguns aspectos da altmetria, área comumente associada a métricas como a bibliometria, cientometria e webometria, mas com importantes diferenças, com intuito de contribuir com o seu entendimento, institucionalização e consolidação. Método. O artigo é uma abordagem teórica sobre a temática altmetria, sendo elaborado a partir de um conjunto de textos selecionados em bases de dados internacionais. A bibliografia selecionada subsidiou análises críticas e reflexivas sobre o tema. Resultados. O texto trouxe reflexões sobre a altmetria e sua fundamenteção teórica, buscando-se discutir a definição da área sua relação com outros estudos métricos da informação e as complexidades e desafios inerentes à produção e uso de indicadores altmétricos. Conclusões. A área possui grande potencial, mas carece de mais reflexão, análises aprofundadas e discussão sobre seus fundamentos. Existem incertezas relacionadas à institucionalização da área e controvérsias sobre as possibilidades dos indicadores para medir o “impacto” da produção acadêmica.Objective. It aims to discuss some aspects of altmetria, an area commonly associated with metrics such as bibliometrics, scientometrics and webometrics, but with important differences in order to contribute to its own understanding, institutionalization and consolidation. Method. The article is a theoretical approach on the subject altmetria, being elaborated from a set of texts selected in international databases. The selected bibliography subsidized critical and reflexive analyzes on the subject. Results. The text brought reflections on the altmetria and its theoretical foundation, seeking to discuss the definition of the area, its relation with other metric studies of information and the complexities and challenges related to the production and use of altmetric indicators. Conclusions. The area has great potential, but it needs more reflection, in-depth analysis and discussion about its theoretical foundations. There are uncertainties related to the institutionalization of the area and controversies about the possibilities of the indicators to measure the "impact" of academic production

Data science teaching and learning models : focus on the information science area

The Data Science field has become a focus of interest for teaching and research in the Information Science area in the last decade. However, due to the specificity of the area, there are still significant challenges when it comes to building curricula for undergraduate and graduate disciplines. What is observed is that students in the area have learning difficulties when taught by traditional approaches from the hard sciences. One of the most important international scientific journals in Information Science, the Journal of the American Society for Information Science and Technology (JASIST), opened a call for articles for a special issue of the journal with a focus on discussing the specificities of Data Science in its relations with Information Science. The call made available an extensive specialized bibliography on the subject. Nine works stand out in this research, directly indicative or referenced from the works indicated that are focused on the issue of teaching Data Science for the area. The analysis of the results points to a specific initiative to form a Data Science curriculum for the Information Science area, the School Data Science Curriculum Committee (iDSCC) initiative, and seven other curriculum models that could be adapted.The Data Science field has become a focus of interest for teaching and research in the Information Science area in the last decade. However, due to the specificity of the area, there are still significant challenges when it comes to building curricula for undergraduate and graduate disciplines. What is observed is that students in the area have learning difficulties when taught by traditional approaches from the hard sciences. One of the most important international scientific journals in Information Science, the Journal of the American Society for Information Science and Technology (JASIST), opened a call for articles for a special issue of the journal with a focus on discussing the specificities of Data Science in its relations with Information Science. The call made available an extensive specialized bibliography on the subject. Nine works stand out in this research, directly indicative or referenced from the works indicated that are focused on the issue of teaching Data Science for the area. The analysis of the results points to a specific initiative to form a Data Science curriculum for the Information Science area, the School Data Science Curriculum Committee (iDSCC) initiative, and seven other curriculum models that could be adapted

Eta Carinae: Binarity Confirmed

We report the recovery of a spectroscopic event in eta Carinae in 1997/98 after a prediction by Damineli (1996). A true periodicity with P = 2020+-5 days (0.2% uncertainty) is obtained. The line intensities and the radial-velocity curve display a phase-locked behavior implying that the energy and dynamics of the event repeat from cycle to cycle. This rules out S Doradus oscillation or multiple shell ejection by an unstable star as the explanation of the spectroscopic events. A colliding-wind binary scenario is supported by our spectroscopic data and by X-ray observations. Although deviations from a simple case exist around periastron, intensive monitoring during the next event (mid 2003) will be crucial to the understanding of the system.Comment: 13 pages, accepted by ApJ Letters (January 2000

Mídias sociais em tempos de bibliotecas 2.0: um estudo em Bibliotecas das instituições federais de ensino brasileiras trazendo perspectivas futuras para a preservação digital

This study aims to discuss the main challenges regarding the social participation on the Web by the Brazilian Federal Education Institutions’(IFES) Libraries and the changes related to the these institutions’ activities, especially interactions with their audience. The Research conducted a quantitative approach survey on the use of the main existing social media by these libraries. The survey sought to identify the level of involvement and participation of these libraries in social media. It is understood that this investigation is necessary as a foundation to the urgent need to raise awareness these Brazilian institutions as the valuable potential of interaction with their users through these media, despite the study demonstrated an incipient use. Based on the conducted survey, the study presents a reflection of the importance that it should devote to digital preservation, not only of their collections, but also the relevant records of the social media content. The results show that most brazilian public universities use Web 2.0 tools with social focus, and the greater adoption of Facebook (43%) and Twitter (29%), but only 5% of them use these medias to disseminate the collections. Thus, it was concluded that the use of social media by these libraries still have a lot to develop and consequently the digital preservation actions need to consider the inclusion of content generated by these media that increasingly have become a valuable communication channel

Critérios de avaliação para sistemas de bibliotecas digitais: uma proposta de novas dimensões analíticas

The article presents an overview of the main criteria used by the technical literature in the area of Information Science for analysis and comparison of digital libraries information systems. Points out the features of these criteria, seeking to detail their analytical dimensions, potential and limitations. From this review, the paper proposes a set of analytical dimensions inspired by the Information Architecture theory to organize and complement these systems comparison criteria. It suggests some new analytic dimensions derived from the new social web interaction paradigms and concludes by proposing an integrated set of criteria organized by dimensions that should be taken into account when comparing and analyzing information of digital library systems.O artigo apresenta uma revisão dos principais critérios utilizados pela literatura técnica na área da Ciência da Informação para análise e comparação de sistemas de informação voltados para a criação de bibliotecas digitais. Aponta as características desses critérios, procurando detalhar suas dimensões analíticas, potenciais e limitações. A partir dessa revisão, o artigo propõe um conjunto de dimensões analíticas inspiradas na teoria da Arquitetura da Informação para organizar e complementar esses critérios de comparação de sistemas. Sugere também algumas novas dimensões analíticas oriundas dos novos paradigmas de interação da websocial e conclui propondo um conjunto integrado de critérios organizados por dimensões que deveriam ser levados em consideração quando da comparação e análise de sistemas de informação de bibliotecas digitais

Redes sociais de coautoria: um estudo da dinâmica de desenvolvimento das interações a partir de múltiplos indicadores na área da Ciências da Comunicação

A análise dinâmica de redes sociais é uma área ainda pouco explorada no campo da Ciências da Informação, trazendo a perspectiva de ampliar os estudos estruturais de rede para incorporar aspectos evolutivos e temporais de como a rede se desenvolvem. O artigo trabalha com um estudo de caso na área da Ciências da Comunicação através dos dados coletados do portal Univerciencia.org, aplicando um conjunto de 10 indicadores que serão analisados ao longo de um período de 15 anos num conjunto de 9.864 artigos de revistas produzidos por 9.587 pesquisadores. O artigo mostra como a rede se desenvolve de forma fragmentada e dependente da ação de grupos locais ainda desarticulados entre si

Dark Matter and Galaxy Formation

The four lectures that I gave in the XIII Ciclo de Cursos Especiais at the National Observatory of Brazil in Rio in October 2008 were (1) a brief history of dark matter and structure formation in a LambdaCDM universe; (2) challenges to LambdaCDM on small scales: satellites, cusps, and disks; (3) data on galaxy evolution and clustering compared with simulations; and (4) semi-analytic models. These lectures, themselves summaries of much work by many people, are summarized here briefly.Comment: 37 pages, 20 figures, Lectures at XIII Special Courses at Observatorio Nacional, Rio de Janeiro, Brazil, October 2008. To appear in the Proceeding