55 research outputs found
Rereading the National Library
History and Memory of the national library. The concept of public and national library. Integration between physical and digital library. Reading and citizenship. Transparency. Accessibility. A new conception of the National Library Foundation, based upon an unitarian structure of time, wich holds past present and future, wich gathers a retropective, perspective and prospective approach. Lesson and Life of the national library foundation.História e memória na Biblioteca Nacional. O conceito de biblioteca pública e nacional. Integração entre biblioteca física e digital. Leitura e cidadania. Transparência. Acessibilidade. Uma nova concepção da Fundação Biblioteca Nacional, apoiada na estrutura unitária do tempo, a uma só vez, passado, presente e futuro. Aglutina retrospectivas, perspectivas e prospectivas, no empenho de releitura da lição e da vida da Biblioteca Nacional
MIMICRY OF FISH LARVAE LIVE FOOD WITH PARTICLES OBTAINED BY IONIC GELATION AND COATED WITH PROTEINS THROUGH ELECTROSTATIC INTERACTION
In an attempt to mimic the proximate composition found in Artemia’s nauplii, a type of food commonly used in intensive rearing of fish larvae, inert diets were produced by ionic gelation using either low methoxyl amidated pectin or sodium alginate and subsequently coated with whey proteins by electrostatic interaction. The particles were morphologically characterized by optical microscopy and scanning electron microscopy, showing spherical shape when moist or rehydrated. The resulting particles were characterized according to their proximate composition, average size, and rehydration behavior after freeze drying. The coated pectin and alginate particles, had sizes averaging 256.7 µm ± 17.1 and 241.9 µm ± 7.5, respectively, with no statistical difference. In relation to the contents of lipid, protein, dry-matter, and ash, the resulting particles were similar to the live food. However, an in vivo evaluation with fish larvae becomes necessary to confirm their suitability and functionality
TOXICIDADE AGUDA E HISTOPATOLOGIA DO FÍGADO DE LARVAS DE TRAIRÃO (Hoplias lacerdae) EXPOSTAS À SOLUÇÃO AQUOSA DE FORMALDEÍDO A 10%
O objetivo deste trabalho foi estimar a concentração
letal 50% (CL (I) 50-96h) da solução aquosa de
formaldeído a 10% para larvas de trairão (Hoplias
lacerdae) e avaliar os aspectos histopatológicos no
fígado das larvas expostas a concentrações
subagudas. Para tanto, realizou-se experimento com
seis concentrações crescentes (0,0; 0,5; 1,0; 1,5;
2,0 e 2,5 mL) de formaldeído. Após 96 horas de
exposição foram coletadas as larvas sobreviventes
de cada tratamento. As larvas foram fixadas em
solução de bouin e incluídas em parafina plástica
para a obtenção dos cortes histológicos de 5 µm e
coloração em hematoxilina/eosina. A CL (I) 50-96h para
larvas de trairão foi de 2,021 mL/L e a mortalidade
de 5%, 10%, 10% e 20% para os tratamentos com
0,5, 1,0, 1,5 e 2,0 mL/L, respectivamente, após 96
horas de exposição e de 100% para o tratamento
com 2,5 mL/L após 24 h. Nos tratamentos com 1,0;
1,5 e 2,0 mL/L verificou-se desarranjo cordonal dos
hepatócitos, fusão celular e congestão nos
sinusóides. A solução aquosa de formaldeído a 10%
pode ser utilizada para terapêutica ou profilaxia em
larvas de trairão, em concentrações de 0,5; 1,0 e
1,5 mL/L, devido a baixa mortalidade dos peixes,
porém é necessário alguns cuidados com sua
utilização devido sua moderada toxicidade aguda
The aquaponic principle—It is all about coupling
The aquaponic principle is the coupling of animal aquaculture (e.g. fish) with plant production (e.g. vegetables) for saving resources. At present, various definitions of aquaponics exist, some bearing the risk of misinterpretation by dismissing the original meaning or being contradictory. In addition, there is no standard terminology for the aspects of coupling between the aquaponic subsystems. In this study, we addressed both issues. (1) We developed new or revised definitions that are summarised by: Aquaponic farming comprises aquaponics (which couples tank‐based animal aquaculture with hydroponics) and trans‐aquaponics, which extends aquaponics to tankless aquaculture as well as non‐hydroponics plant cultivation methods. Within our conceptual system, the term aquaponics corresponds to the definitions of FAO and EU. (2) A system analysis approach was utilised to explore different aquaponic setups aiming to better describe the way aquaponic subsystems are connected. We introduced the new terms ‘coupling type’ and ‘coupling degree’, where the former qualitatively characterises the water‐mediated connections of aquaponic subsystems. A system with on‐demand nutrient water supply for the independent operating plant cultivation is an ‘on‐demand coupled system’ and we propose to deprecate the counterintuitive term ‘decoupled system’ for this coupling type. The coupling degree comprises a set of parameters to quantitatively determine the coupling's efficiency of internal streams, for example, water and nutrients. This new framework forms a basis for improved communication, provides a uniform metric for comparing aquaponic facilities, and offers criteria for facility optimisation. In future system descriptions, it will simplify evaluation of the coupling's contribution to sustainability of aquaponics.Belmont ForumEuropean Commission via the CITYFOOD projectPeer Reviewe
Slightly saline water increases the larviculture efficiency of freshwater Neotropical fish
O objetivo deste trabalho foi avaliar o efeito de água levemente salinizada sobre a larvicultura intensiva do tambaqui, matrinxã, apaiari e piau, durante os dias iniciais de alimentação. As larvas foram mantidas em água artificialmente salinizada, em concentrações de 0 (água doce) a 14 g L‑1 de NaCl (intervalo de 2,0 g L‑1 ), e foram alimentadas com duas porções diárias de náuplios de Artemia, de acordo com protocolo para cada espécie, em delineamento inteiramente casualizado, com três repetições. Larvas de tambaqui, matrinxã e apaiari podem ser cultivadas em até 2 g L‑1 de concentração salina, sem prejuízos ao crescimento e à sobrevivência. Larvas de piau foram mais tolerantes e suportaram até 4 g L‑1 de concentração salina. Acima disto, a mortalidade dos peixes aumentou e chegou a 100% à concentração de 6 g L‑1 (matrinxã e apaiari) e de 10 g L‑1 (tambaqui). A salinização da água a 2 g L‑1 proporcionou maior taxa de sobrevivência a larvas de matrinxã e maior crescimento a larvas de tambaqui, apaiari e piau. Estas duas últimas espécies apresentaram melhor crescimento com a maior quantidade de náuplios. Água salinizada a 2 g L‑1 é benéfica para as espécies estudadas, pois otimiza o potencial de crescimento das larvas e o uso de náuplios de Artemia como alimento vivo.The objective of this work was to evaluate the effect of slightly saline water in an intensive larviculture of tambaqui, matrinxã, apaiari, and piau, during the initial days of active feeding. Larvae were reared in artificial saline water, at concentrations from 0 (freshwater) to 14 g L‑1 NaCl (at a 2.0 g L‑1), and fed with two portions of Artemia nauplii, following a specific protocol for each species, in a completely randomized design, with 3 replicates. Tambaqui, matrinxã and apaiari larvae can be reared at saline concentrations till 2 g L‑1 without impairing growth and survival. Piau larvae were more tolerant and endured saline water until 4 g L‑1. At saline concentrations above that, fish mortality increased and reached 100% at 6 g L‑1, for matrinxã and apaiari, and at 10 g L‑1, for tambaqui. Saline water at 2 g L‑1 provided a higher survival for matrinxã, and higher growth for tambaqui, apaiari and piau. These last two species showed a better growth performance with the highest quantity of nauplii. Slightly saline water at 2 g L‑1 is beneficial to these studied species, as it optimizes larval growth potential and the use of Artemia nauplii as live food
Predicted 2100 climate scenarios affects growth and skeletal development of tambaqui (Colossoma macropomum) larvae
Climate changes driven by greenhouse gas emissions have been occurring in an accelerated degree, affecting environmental dynamics and living beings. Among all affected biomes, the Amazon is particularly subjected to adverse impacts, such as temperature rises and water acidification. This study aimed to evaluate the impacts of predicted climate change on initial growth and development of an important Amazonian food fish, the tambaqui. We analyzed growth performance, and monitored the initial osteogenic process and the emergence of skeletal anomalies, when larvae were exposed to three climate change scenarios: mild (B1, increase of 1.8°C, 200 ppm of CO2); moderate (A1B, 2.8°C, 400 ppm of CO2); and drastic (A2, 3.4°C, 850 ppm of CO2), in addition to a control room that simulated the current climatic conditions of a pristine tropical forest. The exposure to climate change scenarios (B1, A1B, and A2) resulted in low survival, especially for the animals exposed to A2, (24.7 ± 1.0%). Zootechnical performance under the B1 and A1B scenarios was higher when compared to current and A2, except for condition factor, which was higher in current (2.64 ± 0.09) and A1B (2.41 ± 0.14) scenarios. However, skeletal analysis revealed higher incidences of abnormalities in larvae exposed to A1B (34.82%) and A2 (39.91%) scenarios when compared to current (15.38%). Furthermore, the bone-staining process revealed that after 16 days posthatch (7.8 ± 0.01 mm total length), skeletal structures were still cartilaginous, showing no mineralization in all scenarios. We concluded that tambaqui larvae are well-adapted to high temperatures and may survive mild climate change. However, facing more severe climate conditions, its initial development may be compromised, resulting in high mortality rates and increased incidence of skeletal anomalies, giving evidence that global climate change will hamper tambaqui larvae growth and skeletal ontogeny. © 2018 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd
Histologia hepática e produção em tanques‑rede de tilápia‑do‑nilo masculinizada hormonalmente ou não masculinizada
The aim of this work was to evaluate the performance and the liver structure health of Nile tilapia hormonally masculinized or nonmasculinized, reared in cages with two protein levels. Two groups of Nile tilapia of Thai lineage (total 2,400), with 127 g initial average weight, were distributed in a completely randomized design with four treatments, in a 2x2 factorial arrangement, corresponding to the groups of hormonally masculinized or nonmasculinized fish, and to diet protein level of 28 or 32% of crude protein, with three replicates. After 115 days feeding, there was no interaction between the factors for final weight, weight gain, feed conversion rate, final length and survival. There was no difference between hormonally masculinized and nonmasculinized fish for final weight, weight gain, and survival, which shows the possibility of their production in cages, without the need of hormonal masculinization. Crude protein at 32% in the diet enables a better performance for both groups. Histological changes in the liver – such as increased cell volume, disruption of the cord‑like arrangements, and increase of vesicles in the hepatocytes – are found in hormonally masculinized fish, and are more pronounced in fish fed 32% crude protein in the diet.O objetivo deste trabalho foi avaliar o desempenho e a sanidade da estrutura hepática de tilápia‑do‑nilo, masculinizada hormonalmente ou não masculinizada, criada em tanques‑rede com dois níveis proteicos. Tilápias‑do‑nilo da linhagem Tailandesa (total de 2.400), com peso médio inicial de 127 g, foram distribuídas em delineamento inteiramente casualizado, com quatro tratamentos, em arranjo fatorial 2×2, correspondente aos grupos de tilápias masculinizadas hormonalmente ou não masculinizadas e ao teor proteico na dieta de 28 ou 32% de proteína bruta, com três repetições. Após 115 dias de alimentação, não houve interação entre os fatores quanto a peso final, ganho de peso, conversão alimentar, comprimento final e sobrevivência. Não houve diferença entre os peixes masculinizados hormonalmente e os não masculinizados, quanto a peso final, ganho de peso e sobrevivência, o que mostra a possibilidade de sua produção em tanques‑rede, sem a necessidade de masculinização hormonal. A proteína bruta a 32% na dieta possibita melhor desempenho para ambos os grupos. Alterações histológicas no fígado – como o incremento do volume das células, o desarranjo da disposição cordonal e o aumento de vesículas nos hepatócitos – são encontradas nos peixes masculinizados hormonalmente e são mais acentuadas nos peixes alimentados com 32% de proteína bruta na dieta
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