Estudo genético da precocidade sexual de novilhas em um rebanho Nelore

Objetivou-se, com este trabalho, estimar a herdabilidade (h²) para prenhez de novilhas e sua correlação genética (rg) com idade ao primeiro parto (IPP), em animais da raça Nelore. A prenhez de novilhas foi definida de três formas: prenhez aos 16 meses (Pr16) - para as novilhas que pariram com menos de 31 meses, atribuiu-se 1 (sucesso) e, para aquelas que pariram após 30,99 meses ou que não pariram, atribuiu-se 0 (fracasso); prenhez aos 24 meses (Pr24) - para as novilhas que pariram até 46 meses (incluindo as Pr16), foi atribuído 1 e, para aquelas que não pariram 0; e prenhez da novilha (PrN) - atribuiu-se classificação 2 para as que pariram com menos de 31 meses, 1 para as que pariram entre 31 e 46 meses e 0 para as que não pariram. Os arquivos, analisados pelo Método R e Inferência Bayesiana, continham registros de 30.802 novilhas desmamadas. As análises forneceram médias de estimativas de h² de 0,52, 0,12 e 0,16 para Pr16, Pr24 e PrN, respectivamente, pelo Método R. O valor médio obtido por Inferência Bayesiana foi de 0,45 para Pr16. A rg estimada entre Pr16 e IPP foi -0,32. Os resultados indicam que, para selecionar para precocidade sexual, é necessário expor todas as fêmeas em idades jovens e que a mensuração da taxa de prenhez por meio da Pr16 é pertinente, uma vez que esta característica apresenta variabilidade genética alta e deve responder eficientemente à seleção com possibilidades de rápido ganho genético. A análise indicou também que Pr16 e IPP são determinadas em grande parte por genes diferentes.

Heritability estimate for stayability in nelore cows

The objective of the present study was to determine the possibility of using stayability (STAY) of dams as a selection criterion for fertility in the Nelore breed. STAY was defined as whether or not a cow calved in a herd at a specific age or after this age given that she had calved at an earlier age. The specific ages studied were 5 (STAY5), 6 (STAY6) and 7 (STAY7) years. Data on 53 271, 46 011 and 41517 animals were analyzed for the respective ages. The Method 91 was used to estimate the variance components and a maximum threshold a posteriori model was used to predict the genetic values. The analyses provided h(2) estimates of 0.117+/-0.003, 0.122+/-0.004 and 0.171+/-0.005 for STAY5, STAY6 and STAY7, respectively. The ease with which the trait can be recorded and the h 2 estimates indicate that the use of this trait as a selection criterion can contribute to increased dam fertility. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Melhoria da qualidade de um processo de usinagem utilizando as técnicas de avaliação de Taguchi

Delivering to the customers a product or service with the expected quality associated to the huge competitiveness that exists in the market nowadays, has been making organizations increasingly focus on quality planning using techniques which are directed towards the continuous improvement process and production optimization. Thus, this paper aims to improve a machining process using the techniques of experimental design to the optimization and this also includes the analysis of the measurement system. For this purpose, the alloy Nimonic 80A, a nickel base superalloy, was used in the process due to its widespread use for high temperatures, applying this study the robust method proposed by Genichi Taguchi, determining the influence of the factors considered input variables, cutting speed, feed rate, depth of cut, type of tool, lubrication, and material hardness, in the output or response variable, surface roughness, concluding with the use of Taguchi orthogonal array L16 and by analysis of ANOVA that the factor feed rate is significant and offers greater effect on the response variable studied, should be set to 0,12mm/rev. Moreover, the factor type of tool has more influence on the process when compared to other factors, being CP250 the one more suitable to the process. Lastly, the interaction feed rate x cutting speed provides greater significance in the process regarding to surface roughness variable, being the best match between them 0,12mm/rev to the feed rate and 90m/min to the cutting speed. In order to evaluate the measurement system, it was applied the repeatability and reproducibility method (R&R), through which we saw that the system needs improvement (R & R = 88.04% >>> 30%) as the value found in the study was well above compared to the one that classifies the system as inappropriate

Determination of the chemical oxygen demand (COD) using a copper electrode: a clean alternative method

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

Morphological and Structural changes of CaxSr1-xTiO3 Powders Obtained by the Microwave-Assisted Hydrothermal Method

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

Photoluminescence of barium-calcium titanates obtained by the microwave-assisted hydrothermal method (MAH)

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

Development and Validation of an UV-Derivative Spectrophotometric Method for Determination of Glimepiride in Tablets

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

Development and Validation of a UV-Spectrophotometric Method for Determination of Flucloxacillin Sodium in Capsules

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development and validation of HPLC method for analysis of dexamethasone acetate in microemulsions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A modified Primal-Dual Logarithmic-Barrier Method for solving the Optimal Power Flow problem with discrete and continuous control variables

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

Structural and morphological characteristics of (Pb1-x Sr (x) )TiO3 powders obtained by polymeric precursor method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Structural transition on Pb1-xSrxTiO3 produced by chemical method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Vacuum effects on massive spinor fields: S-1 x R-3 topology

The aim of this work was to investigate the role played by an external field on the Casimir energy density for massive fermions under S-1 x R-3 topology. Both twisted- and untwisted-spin connections are considered and the calculation in a closed form is performed using an alternative approach based on the combination of the analytic regularization method and the Euler-Maclaurin summation formula. It is shown that no mass scale appears in the final result and, therefore, Casimir effect arises only from the boundary conditions and vacuum fluctuations induced by the coupling with the external field.

Security constrained optimal active power flow via network model and interior point method

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