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排序方式: 共有101条查询结果,搜索用时 858 毫秒
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Alana Batista dos Santos Mara Lúcia Albuquerque Pereira Herymá Giovane de Oliveira Silva Gleidson Giordano Pinto de Carvalho Taiala Cristina de Jesus Pereira Leandro Sampaio Oliveira Ribeiro José Augusto Gomes Azevêdo Maria das Graças Conceição Parada Costa Silva Larisse Borges Sousa Leandro Borges Sousa Daiane de Oliveira Alencar 《Tropical animal health and production》2016,48(3):509-515
3.
In fish larvae the costs of rapid growth may be accommodated by a decrease in the rate of protein turnover or by a reduction in the costs of protein synthesis. Protein growth, synthesis and degradation were measured in yolk-sac larvae of Clarias gariepinus and the costs of protein synthesis and protein growth were estimated. Growth rates were over 100% protein weight day-1. Protein synthesis retention efficiency (retained protein per unit of synthesis) was estimated to be 69.6%, a value comparable to that of larger fish. The larvae used 43% of their oxygen consumption for protein synthesis. Nevertheless, protein synthesis costs were close to theoretical minima. Therefore, the high growth rates of catfish yolk-sac larvae seem to be possible through minimisation of the costs of protein synthesis. These low costs are associated with high rates of protein synthesis (138%protein weight day-1), and elevated RNA concentrations (107 µg RNA mg-1protein), which together suggest very high RNA efficiencies (12.9 g protein synthesized g-1RNA day-1). 相似文献
4.
F. T. Conceição D. S. Sardinha A. D. G. Souza G. R. B. Navarro 《Water, air, and soil pollution》2010,205(1-4):79-91
The chemical dynamics at Meio Stream Basin, São Paulo State, Brazil were evaluated using major elements as natural tracers. The surface water samples from Meio Stream were collected near the mouth of Meio Stream at the confluence with the Mogi-Guaçu River on February 25, 2005, April 20, 2005, and July 8, 2005. Rainwater samples were collected (using a “bulk” collector) for 1 year at one sampling point located about 4 km from downtown Leme city and other possible sources of contamination. The analyses were performed by pH, temperature, dissolved oxygen, electrical conductivity, total solids, sulfate, nitrate, phosphate, alkalinity, chloride, sodium, calcium, potassium, and magnesium. This basin has serious environmental problems in terms of rainwater and surface water quality, which result in the negative annual flux of cations and anions at Meio Stream Basin, with the exception of chlorine. The Meio Stream, downstream from Leme city, receives several elements/compounds through anthropogenic activities, mainly related to the discharge of domestic effluents. Anthropogenic inputs (mining, fossil fuel burning, and agricultural activities) are responsible for the higher concentrations of cations and anions in the rainwater from this basin. 相似文献
5.
Siani AC Tappin MR Ramos MF Mazzei JL Ramos MC De Aquino Neto FR Frighetto N 《Journal of agricultural and food chemistry》2002,50(12):3518-3521
A new chemotype of the aromatic Verbenaceae species Lippia alba Mill. N. E. Br. from southeastern Brazil has recently been shown to have a high content of linalool in the leaf essential oil. Vegetative propagation of this chemotype was conducted at six different locations in Brazil, and the variation of the content and the optical purity of linalool in the oils were verified. Yields (0.6-0.9%, hydrodistillation), chemical composition, linalool content, and optical purity of the oils from all the plants were compared, using GC-FID, GC-MS, chiral chromatography, and retention index calculation. No plant exceeded the matrix in linalool content (46.5 to 90.7%), and the chemical profile of the oils was the same for all the samples. Purification of linalool to a content close to 100% was effected by vacuum distillation of the crude oil. Chiral analysis showed exclusively the presence of S-linalool in all the crude oils and in the distilled samples. 相似文献
6.
Conceição FR Dellagostin OA Paolichi F Leturia AC Gil Turnes C 《Veterinary journal (London, England : 1997)》2004,167(1):53-58
The molecular profile of 30 Moraxella bovis strains, recovered from outbreaks of infectious bovine keratoconjunctivitis in Argentina, Brazil and Uruguay between 1974 and 2001, was determined through randomly applied polymorphic DNA (RAPD) analysis. Molecular profiles of nine strains recovered after 1990 varied from those recovered before 1990. The profiles of 13 strains (48%) differed from those of three vaccinal strains extensively used since 1984 in Argentina and Uruguay. Eight Argentinean strains, one from Brazil and two from Uruguay had identical RAPD profiles. Strains belonging to different serogroups had identical RAPD profiles, demonstrating that this technique was not able to discriminate among strains with low cross-reactivity indices. RAPD may be helpful in the primary characterization of M. bovis strains, but it does not replace serological characterization. 相似文献
7.
Ana Vasques Paula Maia Mariana Pedro Concei??o Santos V. Ramón Vallejo J. Jacob Keizer 《Annals of Forest Science》2012,69(4):499-507
? Context
Maritime Pine forests cover important mountain areas in Portugal and are known to be a particularly fire-prone forest type. Understory composition plays an important role in maintaining biodiversity and ecosystem services after recurrent wildfires.? Aims
This study aims to improve the knowledge on the germination ecology of understory species of Maritime Pine forests, focusing on the importance of seed provenance, including in relation to germination enhancement by heating.? Methods
The selected species were Cistus ladanifer L., Erica australis L., Erica umbellata L., Pterospartum tridentatum L. (Willk), and Genista triacanthos Brot. Seeds were collected from two or three distant populations. Besides a control treatment, two heating regimes were applied, i.e., 100°C during 5?min and 80°C during 30?min.? Results
Heating treatments significantly enhanced germination in four out of the five species. Differences between provenances were most evident for C. ladanifer and E. australis, especially following the heating treatments. Overall, the seeds from the southern provenances germinated better and, at the same time, were smaller.? Conclusion
The present results confirmed that seed provenance should not be ignored as a key factor in germination ecology, so that further work is needed to untangle the roles of environmental and genetic factors in the observed differences between provenances. 相似文献8.
Uemeson José dos Santos Gustavo Pereira Duda Marise Conceição Marques José Romualdo de Sousa Lima Eduardo Soares de Souza 《Arid Land Research and Management》2019,33(3):255-273
Caatinga is a Brazilian dry ecosystem that occupies around 1 million km2 and is one of the largest tropical dry forests of the world. About 46% of the area that was originally covered has been deforested. Land use can cause pronounced reduction in soil carbon stocks that play a major role in the global carbon cycle. The objective of this study was to improve our understanding of the effect of land use on oxidizable carbon fractions, total carbon stocks and humic substances in different layers of soil in a Brazilian semi-arid region. We analyzed soils from tropical dry forest (TDF), forest succession with Anadenanthera falcata (ANA), with Tabebuia alba (TAB), secondary scrubby regeneration (SCR), and non-irrigated maize (MS). Forests showed larger fractions of more labile carbon, except for TDF. The most recalcitrant fraction of carbon stock, humin fraction stock, with the different land use decreased by 38–53% compared to TDF. Oxidizable carbon fractions, carbon stocks, and humic fraction stocks were able to differentiate the successional land uses and agricultural cover from TDF, mainly in the 0–5?cm layer. Our results show that changes in land use, especially with ANA forest succession, showed a larger labile carbon fraction, indicating easy decomposition and loss. Our results provide an alternative tool for the management of deforested areas in tropical dry caatinga ecosystems. This would contribute to the conservation of dry forest systems and could serve as guideline for sustainable management of agriculturally impacted caatinga areas. 相似文献
9.
Gabriela Noronha de Toledo Pamela Rodrigues Reina Moreira Daniele Santos Rolemberg Andréia Coutinho Facin Julio Edward Hough Monteiro Mareliza Possa de Menezes Maria Eduarda Bastos Andrade Moutinho da Conceição Felipe Augusto Ruiz Sueiro Rosemeri de Oliveira Vasconcelos Paola de Castro Moraes Mirela Tinucci Costa Andrigo Barboza de Nardi 《Topics in companion animal medicine》2018,33(2):35-39
Osteosarcoma is the most commonly reported bone tumor in dogs, typically affecting the axial and appendicular skeleton. Involvement of the paranasal sinuses and the nasal cavity is extremely rare. This report describes a 6-year-old, female, cross-breed dog presented with signs of 90 days duration and diagnosed with a mass located in the right nasal cavity. Radiography, rhinoscopy, and computed tomography findings suggested the presence of an intranasal tumor. Osteosarcoma in the nasal cavity was diagnosed based on histopathological examination and clinical and imaging findings. Survival time was 12 months from diagnosis. 相似文献
10.
Rodrigo Otávio
De Almeida Ozório Carlos Andrade Viriato Manuel Freitas Andrade Timóteo Luís Eugénio Castanheira da Conceição Luisa Maria Pinheiro Valente 《Journal of the World Aquaculture Society》2009,40(1):95-103
Although reported as a slow growing species, to date information regarding nutritional dynamics of blackspot seabream, Pagellus bogaraveo, is limited, especially during ongrowing phase. This study determined the effects of different feeding levels on growth response, body composition, and energy expenditure of blackspot seabream juveniles (initial weight = 64 g). Fish were allocated in nine indoor tanks (15 fish per tank) and fed a basal diet twice daily at increasing levels (2.5, 3.3, and 4.1 g feed/kg0.8/d) for 138 d. Growth response decreased with decreasing feeding levels, but only at 2.5 g feed/kg0.8/d (P < 0.001). Differences in growth rates were positively correlated with body lipid content (r2 = 0.90). Net protein utilization decreased with each increase in feeding level. The energy requirement for zero growth (maintenance) and the estimated energy loss on starvation were calculated as 22.6 and 17.9 kJ/kg0.8/d, respectively. The energy cost for protein and lipid gain was calculated as 3.8 and 1.4 kJ/kJ energy deposited, respectively. This study suggested that blackspot seabream may grow slower than the other close‐related species because of its higher demand of dietary protein energy in favor of lipid deposition. 相似文献