Tatiani Reis da Silveira

Tamanho de amostra para estimação do coeficiente de correlação linear de Pearson entre caracteres de milho

The objective of this work was to determine the sample size for estimating the Pearson correlation coefficient among characters from three corn hybrids. For the analyses, 361, 373 and 416 plants were taken randomly from the hybrids single, triple and double, respectively. For each plant, the following characters were measured: major and minor stem diameters, plant and, heights, weight, length and diameter of ear, number of rows per ear, weight and diameter of cob, a hundred-grain weight, number of grain per ear, grain length and grain yield. For each of the 91 pairs of characters and hybrids, the sample size, based on bootstrap with replacement of 1,000 samples, of each simulated sample size, was determined. In the estimation of Pearson correlation coefficient with the same precision, the sample size (number of plants) increases in the direction of character pairs with lower intensity of the linear relationship, independently of the hybrid cross type. For the 91 pairs of characters studied, 252 plants are sufficient to estimate the Pearson correlation coefficient, in the bootstrap confidence interval 95%, equal to 0.30

Tamanho de amostra para estimação do coeficiente de correlação de Pearson entre caracteres de Crambe abyssinica

It is important to dimension correctly the sample size, to estimate the Pearson correlation coefficient among pairs of characters, with acceptable reliability. The aim of this research was to determine the sample size (number of plants) to estimate the Pearson correlation coefficient among 21 characters of crambe (Crambe abyssinica Hochst). An experiment was conducted in the year 2008. At harvest, 75 plants were selected randomly and measured 21 characters. The measures of central tendency, variability, skewness and kurtosis, were done. Normality was verified and investigated the linearity among the characters. The sample size to estimate the Pearson correlation coefficient was calculated, for the amplitude of the confidence interval of 95%, equal to: 0.15; 0.20; 0.25; 0.30; 0.35 and 0.40, for each of 210 pairs of characters. For the 210 characters pairs of crambe, the sample size to estimate the Pearson correlation coefficient, to the amplitude of the confidence interval of 95% equal to 0.15, ranged from 8 to 665 plants.

Dimensionamento amostral para estimação de coeficientes de correlação em híbridos de milho, safras e níveis de precisão

O objetivo deste trabalho foi determinar o tamanho de amostra necessario para a estimacao de coeficientes de correlacao linear de Pearson para hibridos simples, triplo e duplo de milho em safras e niveis de precisao. Em 361, 373 e 416 plantas, respectivamente, dos hibridos simples, triplo e duplo da safra 2008/2009 e em 1.777, 1.693 e 1.720 plantas, respectivamente, dos hibridos simples, triplo e duplo da safra 2009/2010 foram mensurados 12 caracteres: altura de planta; altura de insercao e peso de espiga; numero de fileiras de graos por espiga; comprimento e diâmetro de espiga; peso e diâmetro de sabugo; massa de 100 graos; numero de graos por espiga; comprimento de graos; e produtividade de graos. Em cada hibrido e safra foram estimados os coeficientes de correlacao para os 66 pares de caracteres e determinou-se o tamanho de amostra para estimacao de coeficientes de correlacao em quatro niveis de precisao [amplitudes do intervalo de confianca de 95% (AIC95%) de 0,15, 0,25, 0,35 e 0,45] por meio de reamostragem com reposicao. O tamanho de amostra varia entre hibridos, safras e pares de caracteres. Maior tamanho de amostra e necessario para a estimacao do coeficiente de correlacao entre caracteres fracamente correlacionados e menor tamanho de amostra e necessario para a estimacao do coeficiente de correlacao entre caracteres altamente correlacionados. Independentemente do hibrido, da safra e do par de caracteres, 375, 195 e 120 plantas sao suficientes, respectivamente, para a estimacao de coeficientes de correlacao com AIC95% maximas de 0,25, 0,35 e 0,45.This study determined the sample size necessary for the estimation of the Pearson linear correlation coefficients for single, triple and double corn hybrids in crops and accuracy levels. In 361, 373 and 416 plants, respectively, of the single, triple and double hybrids of the 2008/2009 crop and, in 1,777, 1,693 and 1,720 plants, respectively, of the single, triple and double hybrids of the 2009/2010 crop, twelve traits were measured: plant height, ear insertion height, ear weight, number of grain rows per ear, ear length and diameter, cob weight and diameter, weight of hundred grains, number of grains per ear, grain length and grain yield. Then, in each hybrid and crop, were estimated the correlation coefficients for the 66 pairs of traits and determined the sample size necessary to estimate the correlation coefficients in four accuracy levels [amplitudes of the confidence interval of 95% (ACI95%) of 0.15, 0.25, 0.35 and 0.45], by resampling with replacement. The sample size varies among hybrids, crops and pairs of traits. Larger sample size is required to estimate the correlation coefficient between weakly correlated traits and smaller sample size is needed to estimate the correlation coefficient between highly correlated traits. Independently of hybrid, crop and pairs of traits, 375, 195 and 120 plants are sufficient, respectively, to estimate the correlation coefficients with maximum ACI95% of 0.25, 0.35 and 0.45.

Tamanho de amostra para a estimação da média de duração dos períodos larval, pupal e larval mais pupal de "Microtheca" spp. por bootstrap

The objective of this research was to determine the sample size (number of insects) to estimate the average duration for larval, pupal and larval + pupal periods for M. ochroloma and M. semilaevis. Adults of both species were collected at a 0.25ha experimental area of forage turnip (Raphanus sativus L.) and for laboratory rearing (temperature 25±2°C, relative humidity 60±10% and photoperiod 12 hours). Afterwards larval, pupal and larval + pupal periods were measured, in days, of 119 and 81 insects, respectively, M. ochroloma and M. semilaevis. It was calculated measures of central tendency and variability and determined the sample size using bootstrap with replacement of 10000 samples. For estimating the average larval, pupal and larval + pupal periods, with amplitude of bootstrap confidence interval of 95%, equal a day, 42 and 35 insects are sufficient, respectively for both M. ochroloma and M. semilaevis.

Efeitos colaterais da ranitidina aplicada em dose terapêutica em cães saudáveis

The purpose of this study was to verify if the ranitidine dosage of 2mg kg-1 by intravenous path causes emesis or hypotension in healthy dogs. They were selected 10 Labrador Retriever, 10 Beagles and 10 mongrel dogs, five animals of each sex. The animals were submitted to clinical examination and blood pressure evaluation before ranitidine administration and also 10 minutes and 4 hours after administration of it. After administration was observed that 13.3% of the animals presented normal; 6.7% of the dogs presented apathy; 50% of the animals presented salivation and 30% presented apathy, salivation, emesis mimic or emesis. There was no significative arterial blood pressure decrease after ranitidine administration. It was concluded that ranitidine useful in therapeutic dosage by intravenous path may provoke apathy, salivation, emesis mimic and emesis.

DURAÇÃO DO SUBPERÍODO SEMEADURA-FLORESCIMENTO, CRESCIMENTO E PRODUTIVIDADE DE GRÃOS DE MILHO EM CONDIÇÕES CLIMÁTICAS CONTRASTANTES E PRODUTIVIDADE DE GRÃOS DE MILHO EM CONDIÇÕES CLIMÁTICAS CONTRASTANTES

Estrategias que busquem aumentar a produtividade de palha pelas culturas devem ser implementadas na regiao dos Cerrados, no sentido de consolidar o plantio direto. Objetivou-se avaliar a influencia das epocas de aplicacao e do parcelamento da fertilizacao nitrogenada suplementar a adubacao de semeadura no milho sobre a produtividade de palha de aveia preta, especies espontâneas e a influencia desse parcelamento nos diversos componentes da cultura. Os tratamentos constaram da aplicacao de 70kg/ha de nitrogenio, como dose suplementar a adubacao de semeadura do milho, em epocas distintas: na semeadura da aveia-preta; oito dias antes da semeadura do milho; em cobertura, quando as plantas tinham quatro a cinco folhas; em cobertura, quando as plantas tinham sete a oito folhas. Na semeadura, aplicaram-se 42kg/ha de N em todas as parcelas. A adubacao nitrogenada aplicada na semeadura da aveia nao resultou em aumento da produtividade de palha, na entressafra. Houve aumento da produtividade de palha pelo milho quando se aplicou o nitrogenio suplementar a semeadura, assim como a aplicacao mais proxima da semeadura proporcionou aumento da produtividade em relacao a aplicacao do fertilizante na semeadura da aveia.