Collaboration networks from a large CV database: dynamics, topology and bonus impact

Understanding the dynamics of research production and collaboration may reveal better strategies for scientific careers, academic institutions and funding agencies. Here we propose the use of a large and multidisciplinar database of scientific curricula in Brazil, namely, the Lattes Platform, to study patterns of scientific production and collaboration. In this database, detailed information about publications and researchers are made available by themselves so that coauthorship is unambiguous and individuals can be evaluated by scientific productivity, geographical location and field of expertise. Our results show that the collaboration network is growing exponentially for the last three decades, with a distribution of number of collaborators per researcher that approaches a power-law as the network gets older. Moreover, both the distributions of number of collaborators and production per researcher obey power-law behaviors, regardless of the geographical location or field, suggesting that the same universal mechanism might be responsible for network growth and productivity.We also show that the collaboration network under investigation displays a typical assortative mixing behavior, where teeming researchers (i.e., with high degree) tend to collaborate with others alike. Finally, our analysis reveals that the distinctive collaboration profile of researchers awarded with governmental scholarships suggests a strong bonus impact on their productivity.Comment: 8 pages, 8 figure

The Highly Miniaturised Radiation Monitor

We present the design and preliminary calibration results of a novel highly miniaturised particle radiation monitor (HMRM) for spacecraft use. The HMRM device comprises a telescopic configuration of active pixel sensors enclosed in a titanium shield, with an estimated total mass of 52 g and volume of 15 cm$^3$. The monitor is intended to provide real-time dosimetry and identification of energetic charged particles in fluxes of up to 10$^8$ cm$^{-2}$ s$^{-1}$ (omnidirectional). Achieving this capability with such a small instrument could open new prospects for radiation detection in space.Comment: 17 pages, 15 figure

Caracterização molecular de fitoplasmas associados ao couro-de-sapo da mandioca (Manihot esculenta Crantz).

A doença conhecida como couro-de-sapo da mandioca (Cassava Frog Skin Disease - CFSD) foi relatada pela primeira vez na Colômbia em 1971. No Brasil, essa doença foi constatada no Amazonas, Pará, Bahia e recentemente Rio de Janeiro. A etiologia do couro-de-sapo sempre foi atribuída a um vírus da família Reoviridae (dsRNA) CFSD, porém Alvarez et al. (2009) identificaram na Colômbia um fitoplasma pertencente ao grupo III relacionado a essa doença. Sob condições favoráveis a CFSD promove a redução do rendimento de raízes tuberosas podendo atingir até 100% e no teor de amido acima de 50% (Alvarez et al., 2009). Os seus sintomas característicos depreciam o valor comercial da mandioca por deixar as raízes com aspecto enrugado, com depressões na casca em forma de 'sulcos' ou 'lábios' que quando coalescem formam um padrão do tipo 'favo de mel', além do engrossamento da película (casca), que passa a apresentar um aspecto corticoso e de difícil desprendimento e entrecasca com tonalidade opaca. Medidas de controle que visem o entendimento do comportamento, distribuição e etiologia do couro-de-sapo são necessárias, porém incipientes no Brasil. Neste contexto, o presente trabalho teve o objetivo de identificar e caracterizar o fitoplasma associado ao couro-de-sapo em plantas sintomáticas