990 research outputs found
Endocrine disrupting effects on the nesting behaviour of male three-spined stickleback Gasterosteus aculeatus L
The analysis of patterns of temporal variability in the nesting behaviour of male threespined stickleback (Gasterosteus aculeatus) exposed to the synthetic oestrogen, 17β-ethinylestradiol, revealed immediate, but transient, treatment-related effects. Gluing frequency and time spent near nest were significantly reduced in exposed fish at the beginning of the experiment. The expression of these behaviours subsequently recovered and there was no effect of treatment on nest building success. The potential causes and implications of these findings are discussed
Aquaculture diversification in South America: general views and facts and case studies of the Republic of Chile and the Federative Republic of Brazil.
Aquaculture and aquaculture diversification in South America: Facts and figures. Diversification of aquaculture in South America: a few figures and concepts. Aquaculture and aquaculture diversification in the Republic of Chile: Current situation, production models and strategies. The aquaculture diversification process in the Republic of Chile: recent history and current status. Diversification and the role of government and private industry. Technology and expertise, markets, institutional facilities and governance as drivers and/or constraints to aquaculture diversification in the Republic of Chile. The future of aquaculture diversification in the Republic of Chile. Aquaculture and aquaculture diversification in the Federative Republic of Brazil: Current situation and main species farmed. Recent history and current status of aquaculture diversification: Main drivers, constraints and species. The role of government, private industry and international organizations in aquaculture diversification. Technology and expertise, markets and institutional facilities as drivers and constraints. The future of aquaculture diversification: Main concerns, opportunities, restrictions, main species to consider.bitstream/item/164749/1/CNPASA-2017-fao.pd
Os avanços da aqüicultura.
A produção global da aqüicultura tem apresentado elevados níveis de crescimento nas últimas duas décadas, e no Brasil, esta expansão está expressa no aumento do consumo per capita de pescados, de 6 para 8kg/ano. Este aumento na produção tem gerado excedentes exportáveis que tornaram a balança comercial brasileira superavitária desde 2001 (MDIC/SECEX)
G55.0+0.3: A Highly Evolved Supernova Remnant
Multi-frequency analysis has revealed the presence of a new supernova
remnant, G55.0+0.3, in the Galactic plane. A kinematic distance of 14 kpc has
been measured from HI spectral line data. The faint, clumpy half-shell is
non-thermal and has a physical radius of 70 pc. Using an evolutionary model,
the age of the remnant is estimated to be on the order of one million years,
which exceeds conventional limits by a factor of five. The remnant may be
associated with the nearby pulsar J1932+2020, which has a spin-down age of 1.1
million years. This work implies that the radiative lifetimes of remnants could
be much longer than previously suggested.Comment: 27 pages, 7 figures in 9 files (figures 1 and 2 require 2 files
each), Accepted for publication in The Astrophysical Journal (Jan. 20, 1998
volume
Automatic Detection of Expanding HI Shells Using Artificial Neural Networks
The identification of expanding HI shells is difficult because of their
variable morphological characteristics. The detection of HI bubbles on a global
scale therefore never has been attempted. In this paper, an automatic detector
for expanding HI shells is presented. The detection is based on the more stable
dynamical characteristics of expanding shells and is performed in two stages.
The first one is the recognition of the dynamical signature of an expanding
bubble in the velocity spectra, based on the classification of an artificial
neural network. The pixels associated with these recognized spectra are
identified on each velocity channel. The second stage consists in looking for
concentrations of those pixels that were firstly pointed out, and to decide if
they are potential detections by morphological and 21-cm emission variation
considerations. Two test bubbles are correctly detected and a potentially new
case of shell that is visually very convincing is discovered. About 0.6% of the
surveyed pixels are identified as part of a bubble. These may be false
detections, but still constitute regions of space with high probability of
finding an expanding shell. The subsequent search field is thus significantly
reduced. We intend to conduct in the near future a large scale HI shells
detection over the Perseus Arm using our detector.Comment: 39 pages, 11 figures, accepted by PAS
Radio polarimetric imaging of the interstellar medium: magnetic field and diffuse ionized gas structure near the W3/W4/W5/HB3 complex
We have used polarimetric imaging to study the magneto-ionic medium of the
Galaxy, obtaining 1420 MHz images with an angular resolution of 1' over more
than 40 square-degrees of sky around the W3/W4/W5/HB3 HII region/SNR complex in
the Perseus Arm. Features detected in polarization angle are imposed on the
linearly polarized Galactic synchrotron background emission by Faraday rotation
arising in foreground ionized gas having an emission measure as low as 1
cm^{-6} pc. Several new remarkable phenomena have been identified, including:
mottled polarization arising from random fluctuations in a magneto-ionic screen
that we identify with a medium in the Perseus Arm, probably in the vicinity of
the HII regions themselves; depolarization arising from very high rotation
measures (several times 10^3 rad m^{-2}) and rotation measure gradients due to
the dense, turbulent environs of the HII regions; highly ordered features
spanning up to several degrees; and an extended influence of the HII regions
beyond the boundaries defined by earlier observations. In particular, the
effects of an extended, low-density ionized halo around the HII region W4 are
evident, probably an example of the extended HII envelopes postulated as the
origin of weak recombination-line emission detected from the Galactic ridge.
Our polarization observations can be understood if the uniform magnetic field
component in this envelope scales with the square-root of electron density and
is 20 microG at the edge of the depolarized region around W4, although this is
probably an over-estimate since the random field component will have a
significant effect.Comment: 18 pages, 8 figures (7 jpeg and 1 postscript), accepted for
publication in the Astrophysical Journa
Sistema de inteligência territorial estratégica para aquicultura.
A criação do Sistema de Inteligência Territorial Estratégica para Aquicultura no Brasil (SITE Aquicultura), adotando ferramentas e conceitos de análise espacial e propondo indicadores socioeconômicos, atende à necessidade premente de monitoramento dessa cadeia produtiva. Além disso, pode fornecer subsídios técnicos para o entendimento da configuração geográfica da atividade aquícola. Sob coordenação da Embrapa Pesca e Aquicultura, conta com diversos parceiros e três diferentes financiadores. Um deles é o Projeto Integrado da Amazônia, série de projetos que a Embrapa lidera dentro do Fundo Amazônia, que conta com recursos internacionais doados por alguns países e operacionalizados pelo Banco Nacional de Desenvolvimento Econômico e Social (BNDES), em cooperação com o Ministério do Meio Ambiente. O objetivo principal do SITE Aquicultura é mapear, validar, analisar e disponibilizar dados e informações geográficas sobre a aquicultura, dispostos em Sistemas de Informações Geográficas (SIGs). Os SIGs podem auxiliar na definição, de forma rápida, acertada e oportuna, da tomada de decisão de agentes públicos e privados das cadeias produtivas relacionadas à aquicultura, bem como identificar possíveis necessidades de realinhamento diante dos novos rumos do mercado e de políticas públicas.bitstream/item/219697/1/SITE-aquicultura-01.pd
Relatório técnico do Seminário Nacional de Prospecção de Demandas da Cadeia Produtiva da Pesca: PROSPESQUE.
Resumo. Abstract. Objetivos. Metodologia. Portfólios de projetos e escala de impactos. Apresentação dos portfólios de projetos e encerramento.bitstream/item/122526/1/CNPASA-2012.pd
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