967 resultados para Musschenbroek (P. v. van). album lui ayant appartenu


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P>In livestock genetic resource conservation, decision making about conservation priorities is based on the simultaneous analysis of several different criteria that may contribute to long-term sustainable breeding conditions, such as genetic and demographic characteristics, environmental conditions, and role of the breed in the local or regional economy. Here we address methods to integrate different data sets and highlight problems related to interdisciplinary comparisons. Data integration is based on the use of geographic coordinates and Geographic Information Systems (GIS). In addition to technical problems related to projection systems, GIS have to face the challenging issue of the non homogeneous scale of their data sets. We give examples of the successful use of GIS for data integration and examine the risk of obtaining biased results when integrating datasets that have been captured at different scales.

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

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The dynamical properties of a classical particle bouncing between two rigid walls, in the presence of a drag force, are studied for the case where one wall is fixed and the other one moves periodically in time. The system is described in terms of a two-dimensional nonlinear map obtained by solution of the relevant differential equations. It is shown that the structure of the KAM curves and the chaotic sea is destroyed as the drag force is introduced. At high energy, the velocity of the particle decreases linearly with increasing iteration number, but with a small superimposed sinusoidal modulation. If the motion passes near enough to a fixed point, the particle approaches it exponentially as the iteration number evolves, with a speed of approach that depends on the strength of the drag force. For a simplified version of the model it is shown that, at low energies corresponding to the region of the chaotic sea in the non-dissipative model, the particle wanders in a chaotic transient that depends on the strength of the drag coefficient. However, the KAM islands survive in the presence of dissipation. It is confirmed that the fixed points and periodic orbits go over smoothly into the orbits of the well-known (non-dissipative) Fermi-Ulam model as the drag force goes to zero.

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The influence of dissipation on the simplified Fermi-Ulam accelerator model (SFUM) is investigated. The model is described in terms of a two-dimensional nonlinear mapping obtained from differential equations. It is shown that a dissipative SFUM possesses regions of phase space characterized by the property of area preservation.

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This study investigated the consequences of intrauterine protein restriction on the gastrointestinal tract and particularly on the gene expression and activity of intestinal disaccharidases in the adult offspring. Wistar rat dams were fed isocaloric diets containing 6% protein (restricted, n = 8) or 17% protein (control, n = 8) throughout gestation. Male offspring (n = 5-8 in each group) were evaluated at 3 or 16 weeks of age. Maternal protein restriction during pregnancy produced offspring with growth restriction from birth (5.7 ± 0.1 vs 6.3 ± 0.1 g; mean ± SE) to weaning (42.4 ± 1.3 vs 49.1 ± 1.6 g), although at 16 weeks of age their body weight was similar to control (421.7 ± 8.9 and 428.5 ± 8.5 g). Maternal protein restriction also increased lactase activity in the proximal (0.23 ± 0.02 vs 0.15 ± 0.02), medial (0.30 ± 0.06 vs 0.14 ± 0.01) and distal (0.43 ± 0.07 vs 0.07 ± 0.02 U·g-1·min-1) small intestine, and mRNA lactase abundance in the proximal intestine (7.96 ± 1.11 vs 2.38 ± 0.47 relative units) of 3-week-old offspring rats. In addition, maternal protein restriction increased sucrase activity (1.20 ± 0.02 vs 0.91 ± 0.02 U·g-1·min-1) and sucrase mRNA abundance (4.48 ± 0.51 vs 1.95 ± 0.17 relative units) in the duodenum of 16-week-old rats. In conclusion, the present study shows for the first time that intrauterine protein restriction affects gene expression of intestinal enzymes in offspring.

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Amidos e gomas são hidrocoloides frequentemente usados em sistemas alimentícios com a finalidade de fornecer textura, umidade e mobilidade de água. A interação amido-goma em sistemas alimentícios pode alterar o inchamento do grânulo de amido e as suas propriedades de gelatinização e reológicas. Neste trabalho, o efeito da adição de goma xantana (GX), carboximetilcelulose sódica (CMC) e carragena (CAR) nas concentrações de 0,15, 0,25, 0,35 e 0,45% (p/v) sobre as propriedades de pasta, térmicas e reológicas do amido de mandioca foi estudado. O Poder de inchamento (PI) e a Microscopia Eletrônica de Varredura (MEV) dos géis de amido também foram avaliados. Os resultados obtidos mostraram que a GX apresentou forte interação com o amido, penetrando entre os grânulos e provocando aumento das viscosidades de pasta, PI, G' e G, e redução da retrogradação do amido; CMCS aumentou as viscosidades de pasta, PI, G' e G das misturas, principalmente em função da sua maior capacidade de reter água, e não por causa da interação com o amido; CAR não modificou qualquer das propriedades do amido, porque não houve nenhuma interação entre essa goma e o amido de mandioca nas concentrações usadas.

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Relatam-se dois casos de miocardite em cães. A avaliação radiográfica mostrou pneumotórax e padrão alveolar no lobo diafragmático pulmonar em um cão e arritmia em ambos os cães. As análises das proteínas cardíacas altamente sensíveis, como a CK-MB e a troponina I cardíaca, associadas ao histórico clínico e aos achados eletrocardiográficos, indicaram, com acurácia, a extensão da injúria miocárdica secundária ao trauma.

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Avaliaram-se os efeitos da suplementação de dois tipos de probióticos para cães filhotes, que receberam dois tipos de dieta - de alta e de baixa qualidade -, sobre a digestibilidade dos nutrientes, escore fecal e parâmetros sanguíneos. Foram utilizados 18 animais, distribuídos em três tratamentos. No tratamento 1, controle, os cães receberam somente a ração; no tratamento 2, ração com probiótico 1 (Bifidobacterium) e, no tratamento 3, ração com probiótico 2 (Lactobacillus). O experimento foi dividido em duas fases. Verificaram-se que os valores médios do coeficiente de metabolizabilidade da energia bruta (CMEB) na fase 1, caracterizada pela troca da dieta Super Premium para a dieta Standard, apresentaram resultados significativos (P<0,05), sendo os melhores resultados obtidos nos animais que receberam o probiótico 2. Não houve diferenças significativas (P>0,05) para o escore fecal e para as análises hematológicas.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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O potencial genético para o crescimento de qualquer espécie animal depende das condições ambientais em que são cultivados, como competição por espaço, alimentos e oxigênio. O presente experimento foi conduzido com o objetivo de avaliar o desempenho produtivo de alevinos de tricogaster (Trichogaster trichopterus), uma espécie de peixe ornamental, submetidos a diferentes densidades de estocagem e índices alimentares. Os peixes (com peso médio de 0,56 g &plusmn; 0,09 e 0,96 g &plusmn; 0,13) foram divididos em dois blocos, submetidos às densidades de 5, 10 e 15 peixes/aquário e alimentados a taxas de 3, 6 e 9% do peso vivo/dia. Os peixes foram alimentados, uma vez ao dia, com ração comercial moída e mantidos em aquários (com capacidade para 100 L) dotados de filtro biológico e aeração, com renovação parcial da água. Os parâmetros físico-químicos da água mantiveram-se dentro da faixa de conforto para a espécie, com diminuição do pH e da condutividade no final do período experimental, para a maior densidade (15 peixes/aquário) e índice alimentar mais elevado (9% p.v./dia). A taxa de arraçoamento afetou significativamente o comprimento final, peso final, ganho de peso, a taxa de crescimento específico e o fator de condição. Os peixes alimentados à base de 9% p.v./dia apresentaram os melhores resultados. Para as diferentes densidades de estocagem, apenas o fator de condição apresentou diferença significativa, com os melhores resultados para os peixes cultivados à densidade de 10 peixes/aquário, em relação aos cultivados à densidade de 15 peixes/aquário. Não foram observadas interações significativas entre os índices alimentares e as densidades de estocagem.

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Realizou-se, na Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, um estudo da variação do valor nutritivo do feno de capim-de-rodes (Chloris gayana Kunth), em três tipos de estocagem: em galpão, no campo com cobertura plástica, e no campo com cobertura morta, em três diferentes tempos de armazenamento (60, 120 e 180 dias), com utilização de ensaios de digestibilidade in vivo. O delineamento experimental foi em blocos casualizados, distribuídos em um fatorial 3 x 3 com três repetições. A análise de variância revelou não haver diferenças significativas para os coeficientes de digestibilidade da matéria seca, mas sim para o extrato etéreo e extrativo não nitrogenado digestível, cujas médias foram 54%, 39,86% e 59,02% aos 60, 120 e 180 dias de armazenamento, e de 51,85%, 59,10% e 58,25% para o extrativo não-nitrogenado digestível, respectivamente. Em relação aos tipos de estocagem, os coeficientes de digestibilidade foram: 52,10%, 51,87% e 54,94% para o extrato etéreo, e 58,18% 57,16% e 53,88% para o extrativo não-nitrogenado. A ingestão média de matéria seca pelos animais foi de 72 g/kg P.V.0,75.

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A method for the direct determination of Pb in wines by simultaneous multi-element atomic absorption spectrometry (SIMAAS) using a transversely heated graphite atomizer, Zeeman-effect background corrector and internal standardization is proposed. Bismuth was used as an internal standard and Pd(NO3)(2) plus Mg(NO3)(2) as chemical modifier,to stabilize both the analyte and the internal standard. The implementation of two pyrolysis steps avoided any build-up of carbonaceous residues on the graphite platform. All diluted samples (1 + 1 v/v) in 0.2% v/v HNO3 and reference solutions (5.0-50 mug l(-1) Ph in 0.2% v/v HNO3) were spiked with 25 mug l(-1) Bi. For a 20 mul aliquot dispensed into the graphite tube, a good correlation (r = 0.9997) was obtained between the ratio of the analyte signal to the internal standard signal and the analyte concentration of the reference solutions. The electrothermal behaviour of Pb and Bi in red, white and rose wines were compared. In addition, absorbance variations due to changes in experimental conditions, such as atomizer temperature, integration time, injected sample volume, radiation beam intensity, graphite tube surface, dilution and sample composition, were minimized by using Bi as internal standard. Relative standard deviations of measurements based on integrated absorbance varied from 0.1 to 3.4% and from 0.5 to 7.3% (n = 12) with and without internal standard correction, respectively. Good recoveries (91-104%) for Pb spikes were obtained. The characteristic mass was 45 pg Pb and the limit of detection based on integrated absorbance was 0.9 mug l(-1) Pb. Internal standardization increased the lifetime of the tube by 25%. Direct determinations of Pb in wines with and without internal standardization approaches were in agreement at the 95% confidence level. The repeatability and the tube lifetime were improved when using Bi as internal standard. The improvement in accuracy using an internal standard was only observed when the analytical results were affected by errors.

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Blue luminescence emission around 480 nm through cooperative upconversion from pairs of Yb3+ ions implanted into 60TeO(2)-10GeO(2)-10K(2)O-10Li(2)O-10Nb(2)O(5) tellurite glasses and excited by a cw laser at 1.064 mum is demonstrated. Cooperative luminescence emission enhancement owing to the temperature dependent multiphonon-assisted anti-Stokes excitation process of the ytterbium ions is also observed. The experimental results revealed a fourfold enhancement in the cooperative luminescence emission when the sample was heated in the temperature range of 20 degreesC-260 degreesC. The thermally induced enhancement is assigned to the effective absorption cross-section for the ytterbium ions which is an increasing function of the medium temperature. (C) 2002 American Institute of Physics.

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The use of internal standardization for simultaneous atomic absorption spectrometry (SIMAAS) was investigated for Cd and Pb determination in whole blood. The comparison of thermochemical and physicochemical parameters allowed the selection of Ag, Bi, and Tl as internal standard candidates. Correlation graphs, plotted from the normalized absorbance signals (n = 20) of internal standard (axis y) versus analyte ( axis x), precision and accuracy were used to select Ag as the most appropriate internal standard. Blood samples were diluted (1 + 9) with 0.11% (m/v) Triton X-100 + 1.1% (v/v) HNO3 + 0.28% (m/v) NH4H2PO4 + 10 mug L-1 Ag+. Pyrolysis and atomization temperatures for the optimized heating program were 550 and 1700 degreesC, respectively. Characteristic masses based on integrated absorbance were 1.68 +/- 0.01 pg for Cd and 30.3 +/- 0.1 pg for Pb. The detection limits (DL) were 0.095 +/- 0.001 mug L-1 and 0.86 +/- 0.01 mug L-1 for Cd and Pb, respectively. The mean RSD for all determinations was the same for Cd (13 +/- 9%) with or without Ag as internal standard ( IS). on the other hand, the use of Ag as IS improved the RSD for Pb from 3.6 +/- 4.0% to 2.2 +/- 2.0%. An effective contribution of the internal standard Ag was verified in the recoveries of spiked samples (0.5 mug L-1 Cd2+ and 5.0 mug L-1 Pb2+). The mean recoveries were 81 +/- 8% and 91 +/- 4% for Cd, and 80 +/- 11% and 93 +/- 6% for Pb without and with IS correction, respectively. This is the first application of IS for a simultaneous determination by SIMAAS.

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A method for the direct determination of Ni in soft drinks by graphite furnace atomic absorption spectrometry using a transversely heated graphite atomizer (THGA), Zeeman-effect background corrector, and Co as the internal standard (IS) is proposed. Magnesium nitrate was used to stabilize both Ni and Co. All diluted samples (1+1) in 0.2% (v/v) HNO3 and reference solutions [5.0-50 mu g L-1 Ni in 0.2% (v/v) HNO3] were spiked with 50 mu g L-1 Co. For a 20-mu L sample dispensed into the atomizer, correlations between the ratio of absorbance of Ni to absorbance of Co and the analyte concentration were close to 0.9996. The relative standard deviation of the measurements varied from 0.5 to 3.4% and 1.0 to 7.0% (n=12) with and without IS, respectively. Recoveries within 98-104% for Ni spikes were obtained using IS. The characteristic mass was calculated as 43 pg Ni and the limit of detection was 1.4 mu g L-1. The accuracy of the method was checked for the direct determination of Ni in soft drinks and the results obtained with IS were better than those without IS.