Growth characteristics of skeletal muscle tissue in Oreochromis niloticus larvae fed on a lysine supplemented diet

The effect of lysine amino acid supplementation on the growth characteristics and morphological pattern of skeletal muscle tissue in Nile tilapia Oreochromis niloticus larvae was evaluated. There were four treatments (T) with increasing levels of lysine supplement (T1 = 0.0%: T2 =1.1%; T3 = 1.7%; T4 = 4.0%) and one treatment with a commercial diet (T5). In all treatments, morphological and histochemical muscle tissue analyses were similar. Two distinct layers were identified: a superficial red layer, more developed in the lateral line region, formed by fibres with intense to moderate NADH-TR reaction and strong acid-stable mATPase activity, and a deep white one, most of the Muscle mass, formed by fibres with weak NADH-TR reaction and strong alkali-stable mATPase activity. There was an intermediate layer between these two layers with fibres exhibiting either weak acid-stable or acid-labile mATPase activity. Body mass increase was significantly higher in T5 than in the lysine treatments (T1-T4). There was no difference in number and diameters of muscle fibres between lysine treatments. In T5, muscle fibre diameter and number were higher. The frequency of red fibres with diameters <= 8 mu m was higher in the lysine treatments, and with diameters between 16 and 24 mu m, was higher in T5. Most white fibre diameters in T5 were significantly larger than 24 mu m and in T1-T4 were between 8 and 16 mu m. Cell proliferation was higher in the lysine treatments and muscle growth in T5 was mainly by fibre hypertrophy. (c) 2005 the Fisheries Society of the British

Muscle growth in Nile tilapia (Oreochromis niloticus): histochemical, ultrastructural and morphometric study

Muscle growth in Nile tilapia (Oreochromis niloticus) was studied focusing on histochemical, ultrastructural, and morphometric characteristics of muscle fibers. Based on body length (cm), we studied four groups: G1 = 1.36+/-0.09, G2 = 3.38+/-0.44, G3 = 8.90+/-1.47, and G4 = 28.30+/-3.29 (mean+/-S.D.). All groups showed intense reaction to NADH-TR in subdermal fibers and weak or no reaction in deep layer fibers. In G3 and G4, an intermediate layer was also observed with fibers presenting weak reaction; in G4, groups of fibers with intense reaction were observed in the subdermal region. The myosin ATPase (m-ATPase) activities were acid-stable and alkali-labile in subdermal fibers; most deep layer fibers were alkali-stable and acid-labile. Intermediate fibers were acid-labile and alkali-stable. Two fiber populations were observed near deep muscle layer: one large presenting weak acid- and alkali-stable and the other small alkali-stable.During growth, muscle fiber hypertrophy was more evident in intermediate and white fibers for G3 and G4. However, in these groups, the presence of fiber diameters less than or equal to21 mum suggested that there is still substantial fiber recruitment, confirmed by ultrastructural study, but hypertrophy is the main mechanism contributing to increase in muscular mass. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

Xylanolytic complex from Aspergillus giganteus: production and characterization

An Aspergillus giganteus strain was isolated as an excellent producer of xylanase associated with low levels of cellulase. Optimal xylanase production was obtained in liquid VOGEL medium containing xylan as carbon source, pH 6.5 to 7.0, at 25degreesC and. under shaking at 120 rpm during 84h. Among the several carbon sources tested, higher xylanase production was verified in xylan, xylose, sugar-cane bagasse, wheat bran and corn cob cultures, respectively. Optimal conditions for activity determination were 50degreesC and pH 6.0. The xylanolytic complex of A. giganteus showed low thermal stability with T-50 of 2 h, 13 min and I min when it was incubated at 40, 50 and 60degreesC, respectively, and high stability from pH 4.5 to 10.5, with the best interval between 7.0 to 7.5. This broad range of stability in alkali pH indicates a potential applicability in some industrial processes, which require such condition. Xylanolytic activity of A. giganteus was totally inhibited by Hg+2, Cu+2 and SDS at 10 mm. The analysis of the products from the oat spelts xylan hydrolysis through thin-layer chromatography indicated endoxylanase activity, lack of debranching enzymes and P-xylosidase activity in assay conditions.

Application of crude xylanase from Bacillus licheniformis 77-2 to the bleaching of eucalyptus Kraft pulp

Alkalophilic Bacillus licheniformis 77-2 produced an extracellular alkali-tolerant xylanase with negligible cellulase activity in medium containing corn straw. The effectiveness of crude xylanase on treatment of eucalyptus Kraft pulp was evaluated. A biobleaching experiment was carried out to compare the chlorine saving with pulp treated and untreated by the enzyme. Two-stage bleaching was employed, using a ClO2 chlorination and NaOH extraction (DE sequence). With the enzymatic treatment, in order to obtain the same value of Kappa number and brightness, respectively 28.5 and 30% less ClO2 was required in comparison to the enzymatically untreated samples.

Triple helix conformation of botryosphaeran, a (1 -> 3;1 -> 6)-beta-D-glucan produced by Botryosphaeria rhodina MAMB-05

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The late precambrian K-alkaline magmatism in the Ribeira Fold Belt: a case study of the Piracaia Pluton, State of São Paulo, SE Brazil, and its potential mineralization (Cu, Zn, Gd)

The Pluriserial Ribeira Magmatic System-590 of the Late Precambrian Ribeira Fold Belt comprises seven groups of high-K rocks of crustal or mantle origin with ages ranging between 620 and 570 Ma. One of these groups is represented by transalkaline suites akin to appinitic lamprophyres. The suites assemble one or more of following lithologies: (+/- quartz) gabbros and monzogabbros, (+/- quartz) diorites and monzodiorites, (+/- quartz) monzonites and syenites in addition to rare granites. All these rocks occur together in the Piracaia pluton, State of São Paulo. The mineralogy of the Piracaia suite comprises variable amounts of plagioclase (An 60-10), alkali-feldspars (orthoclase, microcline, albite), ortho- (Fe-hypersthene) and clinopyroxenes (augite), amphiboles (hornblende and rare late Fe-hastingsite), abundant biotite, quartz, opaques, sphene, allanite and zircon. Several magmatic pulses constructed the pluton. The Piracaia magma bulk trend evolved initially along the silica-undersaturation plane with simultaneous fractionation of accessory, mafic and felsic minerals. These are segregated in feldspar-rich cumulates. In the late stage, the evolutionary trend followed two distinct paths: one along the or-ab thermal barrier with the crystallization of syenites; the second one along the thermal valley in the or-ab-qz subsystem, producing quartz-syenites and granites. The source of the Piracaia magma was a 'vein-plus-wall-rock-system '. Together the pulses reflect increasing and decreasing participation of peridotites and mica pyroxenites, respectively, in the magmatogenic process. The magmatic pulses were stored in magma chambers, several drained by deep faults or fractures, which were successively reactivated and recharged. Each new pulse underwent mixing with earlier residual magma, followed by fractionation. During ascent through the hot and thickened post-collisional crust, the magma pulses underwent minor compositional changes by crustal contamination. The concentration of valuable elements (Cu, Zn, Gd) in the Piracaia pluton occurred during two phases of the magmatic evolution. Cu and Zn were enriched in cumulates and Gd was concentrated in residual quartz-syenitic veins. Due to their homogeneous dark colour and texture, the monzodiorites are exploited both for polished dimension stones and supports for sensitive scientific instruments. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Synchrotron structural characterization of electrochemically synthesized hexacyanoferrates containing K(+): A revisited analysis of electrochemical redox

The presumably soluble KFe(+3)[Fe(2+)(CN)(6)] structure of electrochemically synthesized hexacyanoferrate materials (Prussian Blue) containing K(+) ions was determined for the first time in this study. Prior to drawing conclusions from a structural analysis, the main goal was to make a precise analysis of the inferred soluble structure, that is, KFe(+3) [Fe(2+)(CN)(6)], which is frequently referred to in the literature as the final stable electrochemically synthesized structure. Indeed, a successful X-ray powder diffraction experiment using X-ray synchrotron radiation was made of a powder placed in a 0.5 mm diameter borosilicate glass capillary, which was obtained by removing sixty 90 nm thin films from the substrates on which they were prepared. However, the conclusions were highly unexpected, because the structure showed that the [Fe(CN)61 group was absent from similar to 25% of the structure, invalidating the previously presumed soluble KFe(+3)[Fe(2+)(CN)(6)] structure. This information led to the conclusion that the real structure of Prussian Blue electrochemically synthesized after the stabilization process is Fe(4)[Fe(CN)(6)](3)center dot mH(2)O containing a certain fraction of inserted K(+) ions. In fact, based on an electrogravimetric analysis (Gimenez-Romero et al., J. Phys. Chem. B 2006, 110, 2715 and 19352) complemented by the Fourier maps. it is possible to affirm that the K(+) was part of the water crystalline substructure. Therefore, the interplay mechanism was reexamined considering more precisely the role played by the water crystalline substructure and the K+ alkali metal ion. As a final conclusion, it is proposed that the most precise way to represent the structure of electrochemically synthesized and stabilized hexacyanoferrate materials is Fe(4)(3+) Fe(2+)(CN)(6)](3)center dot[K(h)(+)center dot OH(h)(-)center dot mH(2)O]. The importance of this result is that the widespread use of the terms soluble and insoluble in the electrochemical literature could be reconsidered. Indeed, only one type of structure is insoluble, and that is Fe(4)[Fe(CN)(6)](3)center dot mH(2)O hence, the use of the terms soluble and insoluble is inappropriate from a structural point of view. The result of the presence of the [Fe(CN)61 vacancy a, roup is that the water Substructure cannot be ignored in the ionic interplay mechanism which controls the intercalation and redox process, as was previously confirmed by electrogravimetric analyses (Gimenez-Romero et al., J. Phys. Chem. B 2006, 110, 2715 Garcia-Jareno et al., Electrochim. Acta 1998, 44, 395: Kulesza, Inorg. Chem. 1990, 29, 2395).

Relações lineares múltiplas entre deslocamentos químicos em RMN 13C de haletos alifáticos

Os deslocamentos químicos de RMN 13C de carbonos a , b , g e d de 17 conjuntos de haletos (F, Cl Br e I) alifáticos, inclusive compostos mono, bi e tricíclicos, podem ser reproduzidos por uma equação linear de duas constantes e duas variáveis do tipo : d R-X = A*d R-X1 + B*d R-X2 onde A e B são constantes obtidas por regressão multilinear a partir de deslocamentos químicos de 13C; d R-X, o deslocamento químico de 13C do composto com halogênio (R-X); d R-X1 e d R-X2 deslocamentos químicos de outros haletos. Para brometos (R-X) alifáticos a melhor correlação foi obtida com os dados de fluoretos (R-X1) e iodetos (R-X2) com R2 de 0,9989 e desvio médio absoluto (DM) de 0,39ppm. Para cloretos (R-X) a melhor correlação foi com dados de brometos (R-X1) e iodetos (R-X2) com R2 de 0,9960 e DM de 0,76ppm. Para fluoretos (R-X) a melhor correlação foi com brometos (R-X1) e iodetos (R-X2) com R2 de 0,9977 e DM de 1,10ppm e para iodetos (R-X) foi com fluoretos (R-X1) e brometos (R-X2) com R2 de 0,9972 e desvio médio absoluto de 0,60 ppm.

Carbon dioxide efflux in a rhodic hapludox as affected by tillage systems in southern Brazil

Os solos agrícolas podem atuar como dreno ou fonte de C atmosférico, dependendo do sistema de manejo adotado. Este estudo foi desenvolvido em experimento de longa duração (22 anos), durante o período de 30 dias do outono, com o objetivo de avaliar o impacto de sistemas de preparo de solo (preparo convencional-PC e plantio direto-PD) nas emissões de C-CO2 de um Latossolo Vermelho distrófico, em Cruz Alta, RS. As emissões de C-CO2 do solo foram avaliadas com câmaras dinâmica (Flux Chamber 6400-09, Licor) e estática (com captação em solução alcalina), imediatamente após a colheita da soja. A temperatura e a umidade do solo foram registradas, concomitantemente com as emissões de C-CO2, por meio de sensor de temperatura e TDR manual, respectivamente, integrantes do Licor-6400. Estimou-se que, em 30 dias, uma quantidade equivalente a menos de 30 % do C aportado pelos resíduos de soja foi emitida na forma de C-CO2. As emissões de C-CO2 no solo em PD foram similares às emissões do solo em PC, independentemente do tipo de câmara utilizada. Diferenças entre sistemas de preparo quanto à emissão de C-CO2, avaliadas com a câmara dinâmica, foram verificadas somente a curto prazo (leituras diárias), com o PD apresentando maiores emissões do que o PC no início do período experimental e menores no final. A câmara dinâmica foi mais eficiente do que a estática em captar as alterações das emissões de C-CO2 em função da variação da temperatura e a porosidade preenchida por água (PPA) no solo em PD, as quais explicaram 83 e 62 % das emissões de C-CO2, respectivamente. O fator Q10, que avalia a sensibilidade da emissão de C-CO2 à temperatura do solo, foi estimado em 3,93, indicando alta sensibilidade da atividade microbiana à temperatura do solo durante o outono. As emissões de C-CO2 registradas no solo em PD com a câmara estática foram correlacionadas às da câmara dinâmica, porém com valores subestimados em relação àquela notadamente nos maiores valores de fluxo. em condições de baixa temperatura e PPA, o preparo de solo induziu limitado incremento de emissão de C-CO2.

Consumo de nutrientes e desempenho de ovinos alimentados com dietas à base de cana-de-açúcar hidrolisada

O objetivo deste trabalho foi avaliar o consumo de nutrientes e o desempenho de ovinos alimentados com dietas à base de cana-de-açúcar in natura ou hidrolisada. Foram avaliados 18 ovinos, com aproximadamente 22±2,4 kg de peso vivo, distribuídos em delineamento de blocos ao acaso, com 6 repetições, e o peso dos animais foi utilizado como critério para sua distribuição nos blocos. Os animais receberam dietas completas com 50% de volumoso (cana-de-açúcar in natura, tratada com 0,5 e com 0,9% de cal), e 50% de concentrado. As dietas foram formuladas de forma a atender às exigências de manutenção dos animais e os ganhos de 150 g por dia. As variáveis foram: o consumo e a digestibilidade dos nutrientes e o ganho em peso dos animais. A adição do hidróxido de cálcio aumentou a digestibilidade da fibra em detergente neutro. Não foi observada alteração no consumo de nutrientes ou melhora no ganho em peso dos animais alimentados com cana-de-açúcar, tratada com hidróxido de cálcio, a 0,5 e 0,9%, em comparação à cana-de-açúcar in natura. A cana-de-açúcar com adição hidróxido de cálcio pode ser fornecida após 24 horas de armazenamento, sem prejuízo do desempenho dos animais.

Efeito do tratamento das fibras nas propriedades do biocompósito de amido termoplástico/policaprolactona/sisal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desempenho de novilhos recebendo dietas à base de cana-de-açúcar in natura ou hidrolisada

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of calcium pre-rinse and fluoride dentifrice on remineralisation of artificially demineralised enamel and on the composition of the dental biofilm formed in situ

Objective: This in situ blind crossover study investigated the effect of calcium (Ca) rinse prior to the use fluoride (F) dentifrice on remineralisation of artificially demineralised enamel and on the composition of biofilm. Design: During four phases of 14 days, 10 volunteers wore appliances containing two artificially demineralised bovine enamel blocks. Three times a day, they rinsed with 10 mL, of Ca (150 mM) or placebo rinse (1 min). A slurry (1:3, w/v) of F (1030 ppm) or placebo dentifrice was dripped onto the blocks. During I min, the volunteers brushed their teeth with the respective dentifrice. The appliance was replaced into the mouth and the volunteers rinsed with water. The biofilm formed on the blocks was analysed for F and Ca. Enamel alterations were evaluated by the percentage of surface microhardness change (%SMHC), cross-sectional microhardness (% mineral volume) and alkali-soluble F analysis. Data were analysed by ANOVA (p < 0.05). Results: the use of the Ca pre-rinse before the F dentifrice produced a six- and four-fold increase in biofilm F and Ca concentrations, respectively. For enamel, the remineralisation was significantly improved by the Ca pre-rinse when compared to the other treatments. There was a significantly higher concentration of alkali-soluble F in enamel when the F dentifrice was used, but the Ca pre-rinse did not have any significant additive effect. Conclusions: According to our protocol, the Ca pre-rinse significantly increased biofilm F concentration and, regardless the use of F dentifrice, significantly enhanced the remineralisation of artificially demineralised enamel. (c) 2007 Elsevier Ltd. All rights reserved.

Use of a carbon paste electrode modified with spinel-type manganese oxide as a potentiometric sensor for lithium ions in flow injection analysis

A potentiometric sensor constructed from a mixture of 25% (m/m) spinel-type manganese oxide (lambda-MnO2), 50% (m/m) graphite powder and 25% (m/m) mineral oil is used for the determination of lithium ions in a flow injection analysis system. Experimental parameters, such as pH of the carrier solution, flow rate, injection sample volume, and selectivity for Li+ against other alkali and alkaline-earth ions and the response time of this sensor were investigated. The sensor response to lithium ions was linear in the concentration range 8.6 x 10(-5) - 1.0 x 10(-2) mol L-1 with a slope 78.9 +/- 0.3 mV dec(-1) over a wide pH range 7 - 10 (Tris buffer), without interference of other alkali and alkaline-earth metals. For a flow rate of 5.0 mL min(-1) and a injection sample volume of 408.6 muL, the relative standard deviation for repeated injections of a 5.0 x 10(-4) mol L-1 lithium ions was 0.3%.