Showing papers by "Universidade Federal de Viçosa published in 1992"
TL;DR: Rats fed on diet containing chitin had similar weight gain and feed efficiency, but had lower apparent protein digestibility, equivalent liver steatosis, and reduced levels of liver triglycerides and cholesterol.
Abstract: The effect of chitin at the level of 5% in the diet on cholesterol absorption and metabolism was studied in Wistar rats fed on diet containing beef tallow (7%) and cholesterol (1%). When compared with pair-fed controls, rats fed on diet containing chitin had: (1) similar weight gain and feed efficiency, (2) lower apparent protein digestibility, (3) equivalent liver steatosis, (4) reduced levels of liver triglycerides and cholesterol, (5) similar levels of serum and fecal cholesterol, (6) higher excretion of triglycerides in feces.
66 citations
TL;DR: Three-centimeter-long tip cuttings of Sequoia sempervirens (D. Don) Endl were cultivated in vitro continuously in the absence of auxin (basal medium), continually in the presence of Auxin (induction medium), and temporarily in induction medium, followed by transfer into basal medium (sequential medium).
41 citations
TL;DR: Bee population densities in the forest understory are as large as the largest values found for open vegetation in Southeastern Brazil; species richness is also comparable to those of other areas in S southeastern Brazil.
Abstract: The outcome of a wild bee fauna survey in a secondary forest is reported. Sampling was carried out mainly on herbaceous and shrubby vegetation under and at the border of the forest. Results are compared with data collected with the same methodology from a previously surveyed grassland nearby. The secondary forest was richer in Anthophoridae and Apidae species, and less diverse in Megachilidae. Similarity between the two habitats was low. Several unidentified species of Ceratinula, Trichocerapis mirabilis and the stingless bees Melipona bicolor, M. quadrifasciata, M. marginata, Paratrigona subnuda, Scaptotrigona tubiba and S. xanthotricha, are among the species dependent on the forest environment to survive. Bee population densities in the forest understory are as large as the largest values found for open vegetation in Southeastern Brazil; species richness is also comparable to those of other areas in Southeastern Brazil. Sampling strategies are discussed.
35 citations
TL;DR: In this article, the amount of K-fertiliser needed depended on soil K level and site quality and could be as high as 200 kg of K2O/ha.
Abstract: SYNOPSIS Eucalypt plantations have been the main source of wood for pulp and charcoal in Minas Gerais State, Brazil. A considerable part of these plantations is located in the savannah area where soil fertility is low and fertiliser application is necessary to increase forest productivity. Initially, eucalypt fertilisation consisted of applying 100–150g of a NPK mixture (10–28-6) per plant regardless of soil type, species or time of planting. Later, field trials on fertilisation indicated that further growth increase could be obtained if rock phosphate was broadcasted (at about 1,0 t/ha) or banded (at about 0,5 t/ha) in addition to the NPK mixture. The amount of K-fertiliser needed depended on soil K level and site quality and could be as high as 200 kg of K2O/ha. Eucalypt response to N is restricted to sandy soils with low (less than 1,5%) levels of organic matter. In most cases, S application increased eucalypt yield by more than 50%. Species such as Eucalyptus camaldulensis and E. citriodora, when plan...
23 citations
01 Jan 1992
18 citations
TL;DR: This work investigates the attraction of adult males in the field by females that is mediated by a sex pheromone that remains to be identified and dissected female thoraces were more attractive than other body parts.
Abstract: Migdolus fryanus is a sugarcane pest restricted to South America that is becoming more important due to the inefficacy of control methods against it. The larvae bore into the plant root system and the available insecticides can not give adequate protection. So, the search for alternate control strategies is mandatory. However, the literature on bioethological studies of the species is scarce. This work investigates the attraction of adult males in the field by females that is mediated by a sex pheromone that remains to be identified. Dissected female thoraces were more attractive than other body parts. A trap design for monitoring field populations of this species also is presented.
16 citations
01 Jan 1992
16 citations
01 Nov 1992
TL;DR: In this paper, the authors studied the bitangency properties of space curves in general position from a global viewpoint, and obtained some results on their total number of bitangent osculating planes and cross tangents.
Abstract: We study bitangency properties of space curves in general position from a global viewpoint. As a consequence we obtain some results on their total numbers of bitangent osculating planes and cross tangents, and prove that in the absence of both, the number of zero torsion points of a curve in general position is a multiple of 4.
13 citations
TL;DR: Deltamethrin besides B. thuringiensis showed a faster effect over the caterpillar populations and higher efficiency at 200 and 400 ml/ha, but high quality formulations of this bacteria seem to be promising against caterpillars in reforestation areas of the Amazon region.
Abstract: The relative efficiency of Bacillus thuringiensis formulations in aerial applications against Thyrinteina amobia (Lepidoptera: Geometridae) was evaluated in this essay in comparison with deltamethrin. The essay was carried out in Eucalyptus urophylla plantation in Monte Dourado, Fara, Brazil, through aerial application in areas of 10 ha (100 x 1000 m) for each treatment involving commercial formulations of B. thuringiensis and/or deltamethrin. Data were collected in five sample points for each treatment, 24, 40, 72. 96 and 120 hours after the insecticide applications and after 144 hours a drastic spraying with malathion and deltamethrin was made in order to know the total insect number in each sample point. Deltamethrin showed a faster effect over the caterpillar populations and higher efficiency at 200 and 400 ml/ha. The action of B. thuringiensis was slower, but high quality formulations of this bacteria seem to be promising against caterpillars in reforestation areas of the Amazon region, and can be used isolated or in mixture with deltamethrin for a faster effect. Deltamethrin besides B. thuringiensisshowed little effect on predators Hemiptera and because of this it can be applied against eucalyptus caterpillars, preserving their natural enemies.
12 citations
Journal Article•
01 Jan 1992
01 Jan 1992
TL;DR: Ethanologenic strains of Escherichia coli have been developed which can express thermostable enzymes for starch saccharification as intracellular products, which could be used to supply enzymes for yeast-based fermentations while producing ethanol as a co-product.
Abstract: Ethanologenic strains ofEscherichia coli have been developed which can express thermostable enzymes for starch saccharification as intracellular products. These enzymes can be harvested within cells at the end of fermentation and liberated by heating to the temperature at which they exhibit maximal activity (60°C to 70°C). Organisms such as these could be used to supply enzymes for yeast-based fermentations while producing ethanol as a co-product.
TL;DR: Pisolithus tinctorius was the fungus that formed more mycorrhizas with the 6 pine species tested, and Cenococcum geophilum was the least effective fungus in forming myCorrhiza with pine under the experimental conditions.
06 Aug 1992
Journal Article•
TL;DR: Um isolado de cultura monosporica de soja UFV-1 naturalmente infectada, obtido em Sao Gotardo, MG, foi utilizado para investigar a heranca da resistencia a Cercospora sojina Hara.
Abstract: Um isolado de cultura monosporica de soja ( Glycine max (L) Merrill) cv UFV-1 naturalmente infectada, obtido em Sao Gotardo, MG, foi utilizado para investigar a heranca da resistencia a Cercospora sojina Hara Progenies F 1 e F 2 dos cruzamentos Parana X Bossier, Santa Rosa X Bossier, Santa Rosa X IAC-8 e progenies F 2 dos cruzamentos Santa Rosa X Cristalina e Parana X Cristalina, infectadas artificialmente na concentracao de 3 X 10 4 conidios por mililitro, foram avaliadas em condicoes de casa de vegetacao Notas variando de 1,0 (ausencia de sintomas) a 5,0 (infeccao maxima) foram atribuidas ao foliolo mais infectado por planta, sendo consideradas reacao de resistencia as notas de 1,0 a 3,0 e suscetibilidade de 4,0 a 5,0 Para analise dos resultados da segregacao das progenies foi utilizado o teste X 2 De acordo com os resultados obtidos, a heranca da resistencia a C sojina e, provavelmente, controlada por tres genes dominantes: um, principal, que condiciona resistencia, independentemente dos demais; dois complementares, que condicionam resistencia quando ambos os dominantes estao presentes; e suscetibilidade, quando presentes em outra combinacao
TL;DR: Ballesteros et al. as mentioned in this paper showed that the image of a proper closed continuous map, f, from an n -manifold X to an (n + 1)-MANIFold Y, such that H 1 (Y; Z 2 ) = 0, separates Y into at least two connected components provided the self-intersections set of f is not dense in any connected component of Y.
01 Jan 1992
TL;DR: Film test is an unreliable one for screening Eurytrema sp infection in cattle, according to results of fecal samples of EuryTrema sp infected and non infected cattle.
Abstract: Film test was performed in fecal samples of Eurytrema sp infected and non infected cattle but both groups showed similar results. So, it was concluded that film test is an unreliable one for screening Eurytrema sp infection in cattle.
TL;DR: Muitas das especies de insetos associadas ao plantios de eucalipto sao consideradas pragas, enquanto outras ainda nao apresentam uma relacao definida com estas florestas.
Abstract: Muitas das especies de insetos associadas ao plantios de eucalipto sao consideradas pragas, enquanto outras ainda nao apresentam uma relacao definida com estas florestas. Amostragens quinzenais da entomofauna, realizadas com armadilhas luminosas, no periodo de agosto/90 a julho/91, revelaram a existencia de 263 especies de Lepidoptera associadas aos plantios de eucalipto da regiao de Acailândia (Maranhao). Destas, sete sao consideradas pragas primarias: Eupseudosoma aberransSchaus, 1905 e Eupseudosoma involutaSepp, 1852 (Arctiidae), "Thyirrteina leucoceraeaRindge, 1961, Glenaspp., e Oxydia veuliaCramer, 1779 (Geometridae); Nystalea nyseusCramer, 1775 (Notodontidae); Sarsina violascensHerrich-Schaeffer, 1856 (Lymantriidae) e seis pragas sencundarias: Automeris illustrisWalker, 1855 Automenis sp., Hyperchiria incisaWalker, 1855 e Hyfesiasp. (Satumiidae), Cosmosoma augeLinne, 1767 (Amatidae) e idalus affinis(Arctiidae).
TL;DR: It was proved that the number of eggs per gram of faeces in Eurytrema sp naturally infected cattle has low counts and follows a binomial negative frequency distribution model.
Abstract: Fecal samples were taken from 39 Eurytrema sp naturally infected cattle in order to determinate the egg count per gram of faeces. The results showed that the method employed has 94.2% of probability to detected natural cases of infection with only one examination and this value is not related to the parasite load. Besides, it was proved that the number of eggs per gram of faeces in Eurytrema sp naturally infected cattle has low counts and follows a binomial negative frequency distribution model.
TL;DR: Pachysolen tannophilus excreted riboflavin into a synthetic medium withd-xylose as carbon source, when the pH was below 2.0, and the addition of glucose enhanced the quantity of rib oflavinexcreted.
Abstract: Pachysolen tannophilus excreted riboflavin (12.7 m g/ml) into a synthetic medium withd-xylose as carbon source, when the pH was below 2.0. The addition of glucose enhanced the quantity of riboflavin excreted. The greatest riboflavin production was at pH 1.6 after 5 days at 30°C.
12 Aug 1992
Journal Article•
TL;DR: O corte total do porta-enxerto foi o melhor metodo de inducao de brotacao, e o of encurvamento, o menos eficiente, y o de encurVamento resultou em reducao de 42,5 na percentagem de sobrevivencia de enxertos.
Abstract: Este experimento foi conduzido com o objetivo de comparar quatro metodos de inducao de brotacao de enxerto em citros. O limao 'Cravo' ( Citrus limonia Osbeck) foi utilizado como porta-enxerto, tendo sido enxertado com borbulha de laranja 'Pera' ( Citrus sinensis Osbeck). O corte parcial e o corte parcial com inclinacao do porta-enxerto para o lado oposto ao da borbulha foram equivalentes em termos de percentagem de sobrevivencia e taxa de crescimento. O encurvamento do porta-enxerto resultou em reducao de 42,5 na percentagem de sobrevivencia de enxertos, mas esse metodo causou elevada taxa de crescimento. O corte total do porta-enxerto acima do ponto de enxertia resultou em 100% de sobrevivencia, mas esse tratamento causou grande reducao no crescimento e somente 10% das plantas alcancaram altura de 60 cm aos 50 dias. Nao houve diferenca de diâmetro entre as mudas, nos quatro metodos de inducao de brotacao. O corte total do porta-enxerto foi o melhor metodo de inducao de brotacao, e o de encurvamento, o menos eficiente.
TL;DR: The average parasite load is low in the region under study and the occurence ranged between 7.
Abstract: By macroscopic examination, 485 pancreas of cattle from Southwestern localities of Sao Paulo State were checked in order to count the Eurytrema sp specimens. It was concluded that the average parasite load is low in the region under study and the occurence ranged between 7. 2% and 9.8%.
Journal Article•
TL;DR: Agaricus bisporus desidratados (Cogumelos) foram submetidos a avaliacao sensorial visando to avaliar os efeitos de tres pre-tratamentos (branqueamento a vapor, sulfitacao, and um controle) as mentioned in this paper.
Abstract: RESUMO: Cogumelos desidratados (Agaricus bisporus) foram submetidos a avaliacao sensorial visando a avaliar os efeitos de tres pre-tratamentos (branqueamento a vapor, sulfitacao e um controle), duas temperaturas de secagem (60oC e 80oC), duas temperaturas de armazenagem (5oC e 25o C) por um tempo de armazenagem de ate 60 dias. Os atributos sensoriais da cor, sabor e textura foram avaliados por uma equipe treinada constituida por sete provadores, a zero, 30 e 60 dias de armazenagem. Tambem foi conduzido um teste de aceitacao por uma equipe nao treinada, constituida de 25 provadores. Concluiu-se que a temperatura de 60oC foi a mais adequada para a secagem de cogumelos e a sulfitacao, o pre-tratamento que melhor preservou as propriedades sensoriais do produto desidratado. O produto apresentou uma boa qualidade para o consumo, quando submetido a uma avaliacao sensorial, com 60 dias de armazenagem, independentemente das temperaturas de armazenagem estudadas.
PALAVRAS-CHAVE: Cogumelos desidratados; analise sensorial; armazenagem.
TL;DR: In this paper, the mechanisms of action by which aluminium affects phosphate absorption were evaluated in Stylosanthes guianensis (aluminium sensitive) and Stylopsanthes macrocephala (aluminum tolerant) through kinetic studies with aluminium in pre-and co-treatment.
Abstract: The mechanisms of action by which aluminium affects phosphate absorption were evaluated in Stylosanthes guianensis (aluminium‐sensitive) and Stylosanthes macrocephala (aluminium‐tolerant), through kinetic studies with aluminium in pre‐ and co‐treatment. Multiphasic and cooperative models of ions absorption were tested. In the absence of aluminium, S. guianensis, a specie which normaly requires more phosphorus, showed lower rates of phosphate absorption, which was attributed to slower turnover of the carrier. In S. guianensis, the higher rates of absorption may be related to higher turnover and/or higher concentration of the carrier in the roots. Both species showed negative correlation in the absorption of phosphate, but it was more pronounced in S. guianensis. The effect of aluminium seems to be related to the decreased capacity of the carrier to associate with the ion. There may also be a reduction in the turnover of the carrier, which appears to be more pronounced in the tolerant species, redu...