159 research outputs found
DA EVOLUÇÃO URBANA À GEOGRAFIA HISTÓRICA DO RIO DE JANEIRO
Entrevista de Mauricio Abreu concedida a Laurent Vida
REENCONTRANDO A ANTIGA CIDADE DE SÃO SEBASTIÃO
Este artigo discute o processo de instalação da cidade real de São Sebastião do Rio de Janeiro em seusítio definitivo, no século XVI. A partir da análise minuciosa da documentação ainda existente, o trabalho não apenas reconstitui a morfologia original da urbe como identifica as regras e os atores que orientaram sua implantação. São também apresentados quatro mapas conjecturais da cidade quinhentista, que objetivam suprir a enorme carência de documentação cartográfica sobre os primeiros tempos cariocas e constituem representações verdadeiramente inéditas do Rio de Janeiro primitivo.This article discusses the foundation and early growth of the royal city of São Sebastião do Rio de Janeiro. Based on a detailed analysis of the historical sources still available, the original urban morphology is reconstituted and the rules and actors that presided its implementation are discussed. The work offers four conjectural maps of Rio de Janeiro in the sixteenth century, which constitute original cartographical contributions to the historical geography of the city
A avaliação da pós-graduação no Brasil: alguns pontos para sua compreensão e discussão
No Brasil, os programas de pós-graduação stricto sensu são avaliados anualmente pela Capes. Trata-se de processo complexo, necessário e importante, que vem sendo aprimorado a cada ano. A atividade de avaliação possui a grande vantagem de ser realizada pela própria comunidade acadêmica, figurada na Capes por representantes de área, comissões de área e representantes de grande área. Atenção especial é dada pelas diferentes comissões à avaliação qualitativa e quantitativa da produção científica. O sistema tem sido falho, entretanto, ao não associar claramente a atividade de avaliação com a política de fomento acadêmico, disso resultando incongruências graves que precisam ser rapidamente sanadas. Este texto objetiva esclarecer a estrutura do processo de avaliação da Capes, indicando, ponto a ponto, como ele funciona.
A APROPRIAÇÃO DO TERRITÓRIO NO BRASIL COLONIAL
O peso da história ainda se faz sentir bastante no Brasil. Às vésperas de entrarmos no século XXI, somos volta e meia lembrados que muitos problemas do país têm origens distantes no tempo e acompanham-nos desde os primórdios da colonização. Também não são poucas as ocasiões em que nos deparamos com linguagens barrocas e com termos antigos e estranhos, incompreensíveis até mesmo para o cidadão esclarecido, mas que ainda continuam a ser utilizados, notadamente nos meios jurídicos. E é com espanto ainda maior que descobrimos que muitos desses “anacronismos” são ainda bastante atuais e continuam a fazer sentir o seu peso na estrutura social do país
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Pervasive gaps in Amazonian ecological research
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
Large-scale and multipolar anisotropies of cosmic rays detected at the Pierre Auger Observatory with energies above 4 EeV
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