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Search Results: 1 - 10 of 10159 matches for " Elias Nunes;Guedes "
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Bayesian analysis for comparison of nonlinear regression model parameters: an application to ruminal degradability data
Rossi, Robson Marcelo;Martins, Elias Nunes;Guedes, Terezinha Aparecida;Jobim, Clóves Cabreira;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010000200027
Abstract: this paper shows the bayesian approach as an alternative to the classical analysis of nonlinear models for ruminal degradation data. the data set was obtained from a latin square experimental design, established for testing the ruminal degradation of dry matter, crude protein and fiber in neutral detergent of three silages: elephant grass (pennisetum purpureum schum) with bacterial inoculant or enzyme-bacterial inoculant and corn silage (zea mays l.). the incubation times were 0, 2, 6, 12, 24, 48, 72 and 96 hours. the parameter estimates of the equations fitted by both methods showed small differences, but by the bayesian approach it was possible to compare the estimates correctly, that does not happen with the frequentist methodology because it is much more restricted in the applications due to the demand for a larger number of presuppositions.
Estima o do fator de condi o de peixes da espécie Tracydoras paraguayensis: uma perspectiva bayesiana = Estimate of the condition factor of fish of the Tracydoras paraguayensis species: a Bayesian perspective
Robson Marcelo Rossi,Terezinha Aparecida Guedes,Vanderly Janeiro,Elias Nunes Martins
Acta Scientiarum : Animal Sciences , 2007,
Abstract: O fator de condi o de peixes, expressa a rela o peso-comprimento e é aceita como um indicador da avalia o do “bem-estar” do animal; quanto maior o peso, melhor deve ser sua condi o de sobrevivência. Este trabalho objetivou ajustar um modelo Gama, da famíliaexponencial com fun o de liga o potência, a dados de medidas de comprimento e peso de peixes da espécie Trachydoras paraguayensis, observados na bacia do Rio Paraná, Paraná-Brasil. As estimativas dos parametros do modelo foram obtidos por dois processos distintos: pelométodo clássico da máxima verossimilhan a e pelo método Bayesiano (MCMC). Observou-se que todas as estimativas Bayesianas (médias à posteriori) para os parametros de loca o foram similares as estimativas clássicas, contudo o parametro de dispers o é inferior ao obtido pela a estimativa clássica, além de fornecer um erro padr o 30% menor. The factor of fish condition expresses the weight-length relationship and it is accepted as an indicator for the evaluation of the animal "well-being"; as larger the weight, best should be your survival condition. This work aims to fit a Gamma model, from the exponential family with power link function, to data of length measurements and weight of fish from the Trachydoras paraguayensis species, observed in the basin of the Paraná River, Paraná-Brazil. The estimates of the parameters of the model were obtained by two different processes: by a classic method (maximum likelihood) and by Bayesian method (MCMC). It was observed that the Bayesians estimates (posterior mean) of the parameters of interest were similar to the classic estimates, the dispersion parameter, it underestimated the classic estimate, however the dispersion parameter is inferior to the obtained by the classic estimate, besides supplying a standard mistake 30% smaller.
Curvas de probabilidade de postura de codornas = Laying probability curves in quails
Robson Marcelo Rossi,Elias Nunes Martins,Terezinha Aparecida Guedes,Clédina Regina Acorsi
Acta Scientiarum : Animal Sciences , 2009,
Abstract: Para se estabelecer um modelo para a produ o diária de ovos de 308, 374 e 378 codornas de postura, respectivamente, das distintas linhagens L1, L2 e L3, avaliou-se, em um período de 90 dias de produ o inicial, a utiliza o de três modelos distintos, em umaabordagem Bayesiana. Observou-se que um modelo do tipo log-linear condicional n o é adequado para ajustar os dados para nenhuma das três linhagens analisadas. Alternativamente, que os dados podem ser ajustados de forma mais adequada quando se utiliza um modelo deefeitos aleatórios com fun o de liga o logística, considerando-se que θij é a probabilidade de postura da ave i no dia tj, na forma θij = exp(αi + βitj)/[1 + exp(αi + βitj)], em que os parametros α e β representam, respectivamente, o início da postura e a evolu o da postura da ave. Considerando-se os efeitos de dois níveis de eclos o e de dieta no modelo, observou-se que as mesmas n o apresentaram ser significantes. Por meio de contrastes Bayesianos, verificaram-sediferen as significativas entre linhagens em favor de L1, considerando-se os parametros das curvas de probabilidade de postura média. A superioridade da linhagem L1 deve-se ao início precoce da postura e à maior persistência média de produ o. In order to establish a model for the daily egg production of 308, 374 and 378 laying quails from strains L1, L2 and L3, respectively, this study evaluated, during a 90-day period of initial production, the use of three distinct models in a Bayesian approach. It was observed that a model of the conditional log-linear type is not appropriate to adjust the data for any of the three analyzed strains. Alternatively, that data can be adjusted more adequately using a random effects model with a logistic linking function, considering that θij is the laying probability of the bird i in tj days, as θij = exp(αi + βitj)/[1 + exp(αi + βitj)], in which the parameters α and βrepresent, respectively, the beginning of the laying and the quail’s laying evolution. Considering the effects of two levels of hatching and of diet, it was observed that they were not significant. Through Bayesian contrast, significant differences between strains in favorof L1 were noticed, considering the parameters of laying average probability curves. The superiority of line L1 is due to the precocious beginning of the laying and the higher average persistence in the production.
Macronutrients Omission in the Growth of Cotton, BRS Topázio Cultivar Grown in Nutritious Solution  [PDF]
Felipe Guedes De Souza, Lucia Helena Garófalo Chaves, Allan Nunes Alves, Jorge Alves De Souza
American Journal of Plant Sciences (AJPS) , 2017, DOI: 10.4236/ajps.2017.810157
Abstract: With the objective to determine the probable causes of the appearance of abnormalities in BRS Topázio cotton plants, a greenhouse experiment was carried out per subtraction, in which nutrients were omitted: N, P, K, Ca, Mg and S, totalizing 21 experimental units. The omission of N, P, K and Ca in the nutrient solution reduced the biometric characteristics of the cotton crop, with K and Ca being the most affected by these characteristics. The visual symptoms in cotton plants are seen with more severity in the lack of K, P, K Ca and Mg elements. The omission of S did not affect the development of the plants.
Aspectos genéticos de curvas de probabilidade de postura em codornas
Rossi, Robson Marcelo;Martins, Elias Nunes;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010000800012
Abstract: it was evaluated in this work the components of (co)variance and heritability of the parameters of egg production curve in quails in a model of double stages: the first stage is composed of the adjustment of a nonlinear curve, and the second is composed of the assessing of the genetic parameters obtained by the animal model. it was used daily individual records from laying to 90 days, starting with the first egg in the batch, of 308, 374 and 378 birds from three lines. in each strain, there was no difference between the components of (co)variance neither heritability for rations containing different energy levels (2,900 or 2,500 kcal/kg me), indicating that there was no heterogeneity of variance. however, values of genetic correlations were in the order from 0.53 to 0.65 for the α parameter and, for β from 0.28 to 0.30, indicating one existing genotype x environment interaction. estimates of heritability, respectively in the three lines, for the α and β parameters in the high energy diet were 0.21 and 0.50, 0.12 and 0.49, 0.12 and 0.48, and for the low energy diet 0.23 and 0.50, 0.13 and 0.50, 0.10 and 0.47. estimates of the components of (co)variance and heritability were different among the lines, for the two curve parameters. one line showed higher heritability for the α parameter, indicating greater potential for changes by selection for production at the initial stage of laying. considering the β parameter, the three lines have the same potential.
Influência das coletas sistemáticas e parciais na sele??o de codornas por meio de curvas de probabilidade de postura
Rossi, Robson Marcelo;Martins, Elias Nunes;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010000800011
Abstract: this study aimed to verify if the selection is influenced by partial observation of laying instead of observation of total daily posture. on the first state of analyses, through a bayesian model, it was considered as analyzed characteristics the parameters of laying probability curve in a model of random effects with function of logistic connection. on the second stage of the procedure, it was obtained the estimatives of (co)variance components and genetic parameters. it was observed an overestimation of the production mean curve for the total sample in systematic collections (collected once every 14 days, 1 or 2 times every 7 days) and partial (on 15, 30, 45, 60, 75 and 90 consecutive days). for the parameter that represents the beginning of laying (a), the heritability values were 0.54; 0.14; 0.12 and 0.07; and for the parameter that represents the laying evolution (β), they were; 0.36; 0.37; 0.40 and 0.47, respectively, in the systematic and total collections. in partial and total collections, respectively, the values were 0.04; 0.03; 0.06; 0.12; 0.17 and 0.25; 0.25; 0.33; 0.33; 0.32; 0.41 and 0.51. in the systematic collections, as heritability values for the parameters that represent the beginning of laying decreases, the other increases; however, as the sample size increases in partial collections, the values increase for both parameters. within the top 100 animals classified according to a mediated selection index, the correlation among the scores of selected animals in the sub-samples and the total sample is low (from -0.13 to 0.13) indicating that the used selection index is affected.
Optimization Techniques and Development of Neural Models Applied in Biosurfactant Production by Bacillus subtilis Using Alternative Substrates  [PDF]
Juliana Ferrari Ferreira Secato, Brunno Ferreira dos Santos, Alexandre Nunes Ponezi, Elias Basile Tambourgi
Advances in Bioscience and Biotechnology (ABB) , 2017, DOI: 10.4236/abb.2017.810025
Abstract: Bacillus subtilis was investigated as production of biosurfactant using a combination based on waste of candy industry and glycerol from biodiesel production process as only substrate. The experimental design chosen for optimization by response surface methodology was a central composite rotatable design (CCRD) and dry weight (DW) and crude biosurfactant (CB) concentrations were selected as responses in analysis. Two techniques were implemented response surface methodology (RSM) and artificial neural network (ANN). First challenge of study was to assess the effects of the interactions between variables and reach optimum values. With the CCRD results, RSM and ANN models were developed, optimizing the production of biosurfactant. The correlation coefficients (R2) of RSM models explained 88% for DW and 73% for CB of the interactions among substrate concentrations, while ANN models explained 99% for DW and 98% for CB, demonstrating that developed ANN models were more accurate and consistent in predicting optimized conditions than RSM model. The maximum DW and CB produced in the optimum conditions were 25.60 ± 5.0 g/L and 668 ± 40 mg/L, respectively. The crude biosurfactant also showed applications in cases of oil spreading in water due to clear zone produced in Petri dishes assays.
CCDM: um modelo de terceiriza??o em laboratório de presta??o de servi?os
Alcantara, Nelson Guedes de;Kuri, Sebasti?o Elias;
Produ??o , 1998, DOI: 10.1590/S0103-65131998000200001
Abstract: the increase of research and development equipment costs and the need of updating specialized staff has been the main reason for the cease of several industrial r&d laboratories. as r&d is essential for new products in a very competitive market, several industry-university cooperative research centers have been created in the developed countries. in brazil the first center created by the government is located at the federal university of s?o carlos: the center for characterization and development of materials - ccdm, a us$ 5 millions project. the main difference among ccdm and the existing r&d centers in brazil is that the ccdm is a non-profitable institution, has to be selfsupported and provides services to the industries, universities and research centers. this paper will present the experience of this first center in brazil. the continued growth and success of this outsourcing center should lead to considerable progress in research and development in the field of materials science and engineering.
Dry Matter Production and Nutritional Status of Sunflower Grown in Nutrient Solution under Macronutrient Omission  [PDF]
Allan Nunes Alves, Felipe Guedes de Souza, Lúcia Helena Garófalo Chaves, Ana Carolina Feitosa de Vasconcelos
Agricultural Sciences (AS) , 2018, DOI: 10.4236/as.2018.911103
Abstract: The objective of this study was to evaluate the effect of omission of macronutrients on dry matter production and on the nutritional status of sunflower cv. BRS 122. The experiment was carried out in a greenhouse, in randomized blocks, with seven treatments corresponding to the Hoagland & Arnon standard solution (1950) and the individual omission of N, P, K, Ca, Mg and S, in three replicates. After 50 days of sowing, the dry matter and the nutritional status of the plants were evaluated. The omission of N, P, K, Ca, Mg and S limited the dry mass production of sunflower cv. BRS 122 in relation to the complete solution, besides causing nutritional imbalance due to the interaction between the nutrients. The omission of the macronutrients K, Ca, and Mg caused the higher imbalances in the plants, highlighting the elevated N contents in these treatments comparing to the complete solution.
Transtornos alimentares na vis?o de meninas adolescentes de Florianópolis: uma abordagem fenomenológica
Nunes,Arlene Leite; Vasconcelos,Francisco de Assis Guedes de;
Ciência & Saúde Coletiva , 2010, DOI: 10.1590/S1413-81232010000200030
Abstract: the article aims to understand the meaning of the teenagers' experience of having ed (eating disorders), underscoring the aspects related to eating, from a phenomenological perspective. seven female teenagers with ed being taken care in florianópolis, santa catarina state, were interviewed. a categorization was made to reach the perception of the general structure of the experience, extracting the structure of the past experience. nine signification units that assessed the life experience were identified: the representation of the food, eating habits, food that no longer were eaten, food that they had began eating, the use of soda, food choices, the composition of the meals, family eating habits and healthy food. these showed the suffering that permeates the existence of all the interviewed teenagers, whether for gaining weight, or not considering themselves thin enough, eating too much, not eating at all, forcing vomiting, taking laxatives and diuretics, trying to commit suicide, seeing the parents suffering, not feeling understood by the others, or by themselves. this research allowed us to study this phenomenon from another angle, the relation with the food, confirming how much the way our relation to food is connected to emotional matters. it also allowed showing how it is to live with an ed from the view of each of the interviewed teenagers.
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