944 resultados para potential nutrient use efficiency


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Objetivou-se com este trabalho avaliar desempenho, parâmetros de eficiência e correlações fenotípicas entre medidas de eficiência energética de animais Nelore selecionados para peso pós-desmame e classificados quanto ao consumo alimentar residual, calculado pela diferença entre o consumo observado e o predito, com base no peso vivo médio metabólico e no ganho médio diário. Assim, os animais foram classificados em três grupos: alto (> média + 0,5 desvio-padrão; menos eficientes); médio (± 0,5 desvio-padrão da média); e baixo (< média - 0,5 desvio padrão; mais eficientes) consumo alimentar residual. Não foram observadas diferenças nos pesos vivos inicial e final, no ganho médio diário e no consumo de matéria seca entre os grupos. Animais com baixo consumo alimentar residual mostraram-se também com melhor eficiência alimentar, conversão alimentar e eficiência parcial de crescimento e não apresentaram diferenças em relação aos outros grupos quanto à taxa de crescimento relativo e taxa Kleiber. O consumo alimentar residual apresentou correlação significativa com eficiência alimentar (_0,25), conversão alimentar (0,25), eficiência parcial de crescimento (_0,37) e consumo de MS (0,16) e não apresentou correlação significativa com peso vivo (0,04), ganho médio diário (_0,02), taxa de crescimento relativo (_0,03) e taxa de Kleiber (_0,05). Foram encontradas correlações significativas entre conversão alimentar e peso vivo inicial (0,34) e ganho médio diário (_0,46). Eficiência parcial de crescimento apresentou correlação significativa comtodos os outros parâmetros de eficiência analisados. O consumo alimentar residual, em comparação às demais medidas de eficiência energética, apresenta grande potencial na eficiência produtiva, sendo independente de crescimento e tamanho dos animais.

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Syagrus schizophylla (Mart.) Glass. belongs to the Arecaccae family. This palm is native of Brazil and presents great potential for use in gardens and cultivation in pot. Palms species, with relatively few exceptions, can only be propagated from seeds; even so, there are no reports in the literature about the germination of this palm seeds. The seed maturity is a factor that interferes in the success of the germination process. For some species, studies showed that palm seeds germinated better when the fruits were completely ripe (showing full color) and for other, when they were with green coloration. Several species of the Arecaccae family presents physical dormancy of seeds in varied degrees, demanding treatments for improve germination. The objective of this work was to study the effects of maturation and of the scarification on seed germination of S. schizophylla. The experimental design used was a factorial 3 x 2 (3 maturation stadiums: green, half-ripe - yellow and completely ripe - red; and mechanical scarification: with and without), entirely casualized, with four replications of 15 seeds per plot. The seeds (with 32,43% of humidity) were placed in plastic boxes with sand (60% of humidity, placing water according to weight in each three days), under controlled conditions of alternated temperature of 25-35 degrees C, photoperiod of 12 hours. The percentage of germination and the speed germination index (SGI) were evaluated until 79 days. It was observed that, so much for germination percentage as for SGI, there was not significant difference for the interaction among the two factors, maturation stadium and scarification, however, there were significant differences among the maturation stadiums and between seeds scarified or not. The seeds from green fruits presented lower germination percentage and slower germination when compared with seeds from yellow or red fruits; the seeds from yellow or red fruits didn't differ statistically to each other. To seeds scarificated, independently of the maturation stadium, presented germination percentage significantly larger and the germination was significantly faster when compared with the seeds without scarification.

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Six Welsh gelding ponies were premedicated with 0.03 mg/kg of acepromazine intravenously (i.v.) prior to induction of anaesthesia with midazolam at 0.2 mg/kg and ketamine at 2 mg/kg i.v.. Anaesthesia was maintained for 2 h using 1.2% halothane concentration in oxygen. Heart rate, electrocardiograph (EGG), arterial blood pressure, respiratory rate, blood gases, temperature, haematocrit, plasma arginine vasopressin (AVP), dynorphin, beta-endorphin, adrenocorticotropic hormone (ACTH), cortisol, dopamine, noradrenaline, adrenaline, glucose and lactate concentrations were measured before and after premedication, immediately after induction, every 20 min during anaesthesia, and at 20 and 120 min after disconnection. Induction was rapid, excitement-free and good muscle relaxation was observed. There were no changes in heart and respiratory rates, Decrease in temperature, hyperoxia and respiratory acidosis developed during anaesthesia and slight hypotension was observed (minimum value 76 +/- 10 mm Hg at 40 mins), No changes were observed in dynorphin, beta-endorphin, ACTH, catecholamines and glucose, Plasma cortisol concentration increased from 220 +/- 17 basal to 354 +/- 22 nmol/L at 120 min during anaesthesia; plasma AVP concentration increased from 3 +/- 1 basal to 346 +/- 64 pmol/L at 100 min during anaesthesia and plasma lactate concentration increased from 1.22 +/- 0.08 basal to 1.76 +/- 0.13 mmol/L at 80 min during anaesthesia, Recovery was rapid and uneventful with ponies taking 46 +/- 6 min to stand. When midazolam/ketamine was compared with thiopentone or detomidine/ketamine for induction before halothane anaesthesia using an otherwise similar protocol in the same ponies, it caused slightly more respiratory depression, but less hypotension. Additionally, midazolam reduced the hormonal stress response commonly observed during halothane anaesthesia and appears to have a good potential for use in horses.

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An experiment was conducted to study nitrogen absorption and translocation in grain sorghum plants during their reproductive growth. Sorghum was grown in four row spacings: 50 and 70 cm in single rows, 80 and 120 cm in double rows 20 cm apart. Plant populations were 71000, 142000 and 213000 plants/ha. After flowering, samples were taken at 12 day intervals, and the plants were divided into grains and stover, where N was analyzed. There was an increase in N concentration in lower plant populations and in wider row spacings. However, total nitrogen accumulation (in kg/ha) increased as the number of plants was increased. In the vegetative parts of the plants there were higher N concentrations in lower populations showing that there was a higher N absorption and a lower translocation to the grains. When grain sorghum was grown in 50 cm rows, there was a high N accumulation, a high N translocation to the grains and the highest yield. This row spacing led to the highest N use efficiency.

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Shiitake (Lentinula edodes (Berkeley) Pegler) is one of the most consumed mushrooms, for both therapeutic purposes and as food, therefore, the study of its biological properties is of great interest for producers and consumers. Aqueous extracts of the shiitake mushroom (L. edodes (Berkeley) Pegler) were evaluated by the micronucleus test (MN) in HEp-2 cells in vitro, to analyze their possible mutagenic and antimutagenic activities. None of the three extract concentrations tested (0.5, 1.0 and 1.5 mg/mL) presented mutagenicity at any of the preparation temperatures (4 degrees C, 22 +/- 2 degrees C and 60 degrees C). In the antimutagenicity evaluation, all extract concentrations at all preparation temperatures presented a strong protective activity for the HEp-2 cells in response to the alkylating agent methyl methanesulfonate (MMS) in the different treatment protocols: pre-treatment, simultaneous treatment and post-treatment. The extracts prepared at 22 +/- 2 degrees C presented the lowest frequencies of MN in the evaluations of mutagenicity and antimutagenicity, indicating these as the best option for potential therapeutic use. (c) 2006 Elsevier Ltd. All rights reserved.

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This work aimed to evaluate root growth, shoot development and nutrient absorption efficiency by rice cultivars Caiapo and Maravilha as affected by lime application. The experiment was carried out in a greenhouse, with treatments set up by Caiapo and Maravilha cultivars in combination with the base saturation (V%) of 10%, 40% and 70%. The experiment was in a randomized complete block design, with four replications. The number of tillers, root length, root dry matter, leaves and stems, leaf content and macronutrients absorption efficiency were evaluated. Comparing cultivars, Maravilha cultivar presented higher root dry weight, root length, number of stems, dry matter of stems and shoot than Caiapo cultivar, as well as accumulated more nutrients in the shoots. on the other hand, nutrient contents were higher in the cultivar Caiapo compared to Maravilha. Maravilha cultivar shows greater root and shoot growth while Caiapo shows higher nutrient absorption efficiency from the soil. The base saturation of 40% is the most effective for both cultivars.

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

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

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Turquoise blue 15 (AT15) is a reactive dye widely used in the textile industry to color natural fibers. The presence of these dyes in effluent and industrial wastewater is of considerable interest due ecotoxicological and environmental problems. The electrochemical reduction of this dye has been investigated in aqueous solution using cyclic voltammetry, controlled potential electrolysis and cathodic stripping voltammetry. Optimum conditions for dye discoloration by controlled potential electrolysis use an alkaline medium. Using cathodic stripping voltammetry a linear calibration graph was obtained from 5.00×10-8 mol L-1 to 1.00×10 -6 mol L-1 of AT15 at pH 4.0, using accumulation times of 180 and 240 s and an accumulation potential of 0.0 V. The proposed method was applied in direct determination of the dye in tap water and in textile industry effluent.

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The development of fast, inexpensive, and reliable tests to identify nontuberculous mycobacteria (NTM) is needed. Studies have indicated that the conventional identification procedures, including biochemical assays, are imprecise. This study evaluated a proposed alternative identification method in which 83 NTM isolates, previously identified by conventional biochemical testing and in-house M. avium IS1245-PCR amplification, were submitted to the following tests: thin-layer chromatography (TLC) of mycolic acids and PCR-restriction enzyme analysis of hsp65 (PRA). High-performance liquid chromatography (HPLC) analysis of mycolic acids and Southern blot analysis for M. avium IS1245 were performed on the strains that evidenced discrepancies on either of the above tests. Sixty-eight out of 83 (82%) isolates were concordantly identified by the presence of IS1245 and PRA and by TLC mycolic acid analysis. Discrepant results were found between the phenotypic and molecular tests in 12/83 (14.4%) isolates. Most of these strains were isolated from non-sterile body sites and were most probably colonizing in the host tissue. While TLC patterns suggested the presence of polymycobacterial infection in 3/83 (3.6%) cultures, this was the case in only one HPLC-tested culture and in none of those tested by PRA. The results of this study indicated that, as a phenotypic identification procedure, TLC mycolic acid determination could be considered a relatively simple and cost-effective method for routine screening of NTM isolates in mycobacteriology laboratory practice with a potential for use in developing countries. Further positive evidence was that this method demonstrated general agreement on MAC and M. simiae identification, including in the mixed cultures that predominated in the isolates of the disseminated infections in the AIDS patients under study. In view of the fact that the same treatment regimen is recommended for infections caused by these two species, TLC mycolic acid analysis may be a useful identification tool wherever molecular methods are unaffordable.

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This paper evaluated the critical level, responsivity and boron use effciency on growth and the biomass production in six Eucalyptus grandis x Eucalyptus urophylla clones (Ca, Cb, Cc, Cd, Ce and Cf). An experiment was carried out in pots containing ground silicon, under greenhouse conditions using four boron rates per solution (0; 0.135; 0.27; 0.54 mg L -1 of B). The treatments were combined in a randomized block experimental design in a 4 × 6 factorial scheme with three replications. Plant height, stem diameter, dry matter production in the shoots of the plant and boron use effciency in the leaves, stem and total dry matter at the 8th month of age were evaluated. Due to boron fertilization, growth and shoot biomass were observed in the Eucalyptus plants after 240 days of being planted in pots. The increases in growth and biomass were 35 to 54% and 21 to 64%, respectively. The boron rates that promoted major growth of the plants were 0.33 to 0.44 mg L -1 of B and in this range the most effcient clone for dry matter production of leaves was Cf and the least effcient one to stem biomass production and the shoot biomass was Cd, no signifcant differences among other clones were observed. The critical level of boron in solution was 0.09 to 0.24 mg L -1 of B in the growth of the plants.

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The objective of this research was to study three methods of parameter determination for irrigation control under different tensions in common bean (Phaseolus vulgaris L.). The treatments were a combination of three methods of parameter determination for irrigation control (tensiometer, water retention curve, USWB Class A pan) with three soil water tensions (1:-30 kPa; 2:-60, kPa both for the whole plant cycle; 3:-60 kPa for the vegetative phase and -30 kPa for the reproductive phase). The experimental design was randomized blocks, factorial 32 with three replicates. Although no significant effect on water use efficiency was found, a tendency for increasing water use efficiency in treatments with tensions of -60 kPa at the vegetative phase and -30 kPa at the reproductive phase was observed in all methods of parameter determination for irrigation control. Water was saved as less irrigation was applied during the vegetative phase and more irrigation at the reproductive phase. No precipitation was observed from June to September 1995, leading to a high yield and therefore to a higher water use efficiency.

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

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The work was realized at the Laboratório de Ensaio de Equipamentos de Irrigação do Departamento de Engenharia Rural da Universidade Estadual Paulista FCA- UNESP de Botucatu - SP, it aims evaluated in bench, the flow of a microsprinkler flow with dynamic nominal 43L h-1, before and after the use of gray water. In the first phase were 25 new emitters were separated and performed tests with clean water, at pressures from 50 to 300 kPa. In a second phase the emitters have been submitted 1000h operating with gray water. At the end of this time, the emitters were submitted again into conditions of initial essay, to evaluate the new costume water effect on medium flow from microsprinkler. At the end we can see that the average flow of the emitters, after use, has declined compared to the emitters discharge before use in 6,6%, the coefficient of variation after use was 5,1%, increased in proportion the coefficient of initial production was 4,3%, the R 2 fell from 0.9946 to 0.9898 and the microsprinkler continued with a high rating, according to the ABNT and ASAE.