263 resultados para seleção de estirpes


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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fez-se um estudo de seleção de métodos para cobre disponível, empregando-se trinta solos coletados na região de Jaboticabal, SP. Os solos utilizados pertencem aos seguintes grandes grupos: Solos Podzolizados de Lins e Marília, variação Lins e variação Marília, Latossolo Vermelho-Escuro fase arenosa, Latossolo Roxo, e Terra Roxa Estruturada. O cobre dos solos foi extraído através das seguintes soluções extratoras: CaCl2 0,5 M; Mg02 2,0 N; CH3COONH4 1,0 N1 pH 6,0 e pH 4,8; HCl 0,05 N e O,1 N; H2SO4 0,05 N; DTPA 0,005 M pH 7,3 e pH 6,0; EDTA 0,01 M + (NH4)2CO3 1,0 MpH 8,6; EDTA 0,02 M + CH3C0011 0,5 M + CH3COONH4 0,5 M pH 4,65 (AAAc-EDTA); e Na2EDTA 1,0%. Foi realizado ensaio em casa de vegetação, e o milho (Zea mays L.) foi empregado como planta teste. Excluindo-se o extrator CaCl2 0,5 M, todos os demais apresentaram coeficientes de correlação entre cobre extraído do solo e o absorvido pelo milho, significativos e próximos uns dos outros. Assim, com base também em parâmetros como o coeficiente de variação, o coeficiente angular e a praticidade do método, pode-se indicar um dos seguintes extratores para a avaliação do cobre disponível dos solos: DTPA 0,005 M pH 7,3, HCl 0,1 N e Na2EDTA 1,0%.

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A total of 8,064 records from weaning weights and conformation scores traits of calves nearly seven month-old were studied. The study included animals from 22 herds from state of Rio Grande do Sul, borned from 1973 to 1985 which were raised on pastures. The weaning weight adjusted to 205-day weight and fat deposition and the relation size-length of body were scored subjectively in a scale from zero to ten. The dates 205-day weight, fat deposition and relation size-length of body were 137.00 +/- .20 kg; 6.38 +/- 01 and 6.77 +/- 01 grades, respectively. The heritability estimates were .25 +/- .03, .38 +/- 04 and .37 +/- 04, respectively. The selection index was more efficient than direct phenotypic selection and this study also indicates that general selection index is not adequated to use it in all farms, and it is not necessary to have accurate economic values. The most important parameters to get good selection are reliable estimates of genetic and phenotypic variances and covariances.

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The purpose of this study was to evaluate methods for predicting availability of Zn in soils. Surface soil samples representing Podzolized soils from Lins and Marilia var. Marilia and var. Lins, medium texture Dark-Red Latosol, Dusky-Red Latosol and Terra Roxa Estruturada, were gathered from fields in Jaboticabal, SP, Brazil. Com was used as indicator plant in a greenhouse experiment. Availability of Zn was determined with: 0.5 M CaCl2, 2.0 N MgCl2, N CH3COONH4 (pH 6.0 and 4.8), 0.05 and 0.1 N HCl, 0.05 N H2SO4, 0.005 M DTPA (pH 7.3 and 6.0), 1.0% Na2-EDTA, 0.01 M EDTA + 1.0 M (NH4)2CO3 (pH 8.6) and 0.02 M EDTA + 0.5 M CH3COOH + 0.5 M CH3COONH4. By using the simple correlation coefficients (Zn extracted from soils x absorbed by plants it can be concluded that the complexant agents and acid solutions showed to be efficient. The salt solutions showed low extraction capacity, low correlation coefficients and less accuracy. By considering aspects as accuracy and easy management DTPA pH 7,3 and Na2-EDTA can be indicated as the most apropriates (r values, respectively, 0.873** and 0.868** and V.C. 7.52% and 7.98%).

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Biofilm formation is considered an advantage for Staphylococcus aureus mastitis isolates, facilitating bacterial persistence in the udder. It requires attachment to mammary epithelium, proliferation and accumulation of cells in multilayers and enclosing in a polymeric matrix known as exopolysaccharide. The objective of this study was to evaluate the ability of Staphylococcus aureus isolated from bovine subclinical mastitis for formation of biofilms. A total of 94 Staphylococcus aureus strains obtained from milk samples of cows suffering from subclinical mastitis in dairy herds on two properties in the state of São Paulo were evaluated. These strains were characterized by in vitro biofilm formation, and by the presence of icaA and icaD genes which are responsible for intercellular adhesion. The results revealed that 98.9% of the isolates produced biofilm in vitro by adherence in sterile 96-well "U" bottom polystyrene tissue culture plates; 95.7% of the isolates possessed the icaA and icaD genes. These bacterial isolates biofilm producers may impair eradication of chronic mastitis, rendering antibiotherapy less effective. The detection of biofilm forming ability in mastitis isolates may provide useful information for more adequate therapeutic regimen and for preventive actions in the control of those bacterial isolates in bovine herds.

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The objectives of this study were to obtain heritability and genetic, phenotypic and environmental correlation estimates for birth (B), weaning (WW), yearling (YW) and 18 - (EW) and 24 - month (TW) weights, and to propose selection criteria for body weight in Canchim cattle. The data were analyzed by the least-squares method with models that included the fixed effects of herd, year and month of birth, sex of calf and age of cow at calving, and the random effects of sire within herd. The heritability estimates obtained were equal to 0.36 0.06 (BW), 0.47 0.06 (WW), 0.53 0.07 (YW), 0.54 0.08 (EW) and 0.27 0.06 (TW). The genetic correlations were equal to 0.51 (BW and WW), 0.36 (BW and YW), 0.14 (BW and EW), 0.00 (BW and TW), 0.92 (WW and YW), 0.77 (WW and EW), 0.75 (WW and TW), 0.94 (YW and EW), 0.86 (YW and TW) and 0.85 (EW and TW). The phenotypic correlations ranged from 0.19 to 0.72, and the environmental correlations from 0.11 to 0.61. The results showed that, in general, mass selection for weight will result in genetic progress, selection for weight at any age will result in correlated changes at other ages, and EW and TW are good selection criteria for increasing weight in the Canchim breed.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Individual data of basic density and volume of wood, pulp kappa number, soluble lignin, cost of pulping process as well as gravimetric gross yield of pulping process were used from 64 trees of Eucalyptus grandis W. Hill ex Maiden from a commercial population at Lençóis Paulista, SP. The Eucalyptus grandis's seeds were originally from a Seed Production Area (SPA) of Duratex S/A at Botucatu, SP. Obtained data were quantified considering objective of maximization no-bleaching pulp and volume and mass wood restriction, mass of residual and soluble lignin, planted area and pulping process cost. it has also been aimed a selection method for matrix trees through mathematical programming techniques. Obtained strategy maximized the economical result, selected matrix trees and followed all limits of technological and organizing productivities imposed by the company. It also aimed the production of no-bleaching pulp within the planned time.

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In breeding programs, the complexity of economically outstanding characters, most of which highly influenced by the environment, makes selection difficult. Using genetic parameters, like heritability and gain with selection, it is possible to identify superior genotypes in early generations. Therefore, the aim of the present research was to compare different selection criteria by the estimated gains and the selected progenies, determining the superior and more similar methods. Augmented block design was used with three additional checks. Twelve hundred genotypes were evaluated. The most expressive expected gains were obtained with direct selection. However, the indices have shown to be more appropriate for selecting superior progenies because of their higher total gains, distributed among all the evaluated characters. The Sum of Ranks Index allowed the highest gains in most of the situations analysed.

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

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Historically, the incorrect waste disposal has been related to epidemics which resulted in thousand of deaths. Despite the efforts to develop sanitary disposal methods in the 19 century, even today, uncontrolled dumps are often found in undeveloped countries. These places are responsible for environment pollution and for several diseases. The process of adequate waste disposal begins with the selection of suitable landfill areas, based on environmental characteristics. The goal of this research was to compare two methods of landfill site selection: the first one developed by IG-SMA (1999), and the other by Basílio (2001). Both methods were developed and applied in the same area - region of Campinas, São Paulo State, Brazil and this fact explains the choice for them; the comparison was made by superposing maps. Despite the same geographic area, the result was very different and few areas in common were found; IG-SMA (1999) obtained more suitable areas than Basílio (2001). This has been attributed to scale, criteria and attribute differences and, as a conclusion, Basílio (2001) was considered more restrictive than IG-SMA (1999).

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)