Relationship between germination and bell pepper seed structure assessed by the X-ray test

Alternative use of the X-ray test to evaluate seed quality has become increasingly diverse. This study was performed primarily to establish experimental procedures and verify the effectiveness of the X-ray test to detect damage or abnormalities in bell pepper (Capsicum annuum) seed structure associated with germination. Five seed lots each of hybrids Reinger and Sentinel were used. Two hundred seeds per lot were exposed to durations and intensities of X-radiation and visually classified into four categories according to the proportion between the area occupied by the embryo and endosperm in relation to the total cavity area in the internal seed structure, e.g. 0, < 50%, 50-75% and 100%. The last category was subdivided into two others based on the occurrence of morphological abnormalities. Seed samples obtained from different X-ray categories were then submitted to germination test at 25ºC for 14 days and subsequently compared with results of the X-ray analysis. Exposure to a 10 kV radiation for 260 s was the most suitable X-ray dose for visualizing seed structure. Seeds in which the area of the internal cavity occupied by the embryo and endosperm varied from 50-75% produced abnormal seedlings or did not germinate. Full seeds (100% of the internal cavity area occupied) with abnormal structure usually originated defective seedlings. As a consequence, the classification of bell pepper seeds according to the proportion occupied by the seed content (embryo + endosperm) allowed a reliable estimation of the degree of seed physical integrity based on X-ray analysis and its association with germination performance.CNPqFAPES

Has core inflation been doing a good job in Brazil?

This paper assesses the performance of the core inflation measures calculated by the Brazilian Central Bank (BCB). The evidence shows that they do not meet some key statistical criteria that a good core inflation should have: unbiasedness and the ability to forecast inflation. That performance stems, to a large extent, from the lack of a well-grounded statistical and economical basis behind them. Three new measures are built and assessed using the same criteria. The evidence shows that their behaviour is more in accordance to what the theory claims. However, they still lack the ability to help forecasting inflation. Hence both the BCB and the market should use core inflation cautiously.Core inflation; inflation; supply shocks; relative prices; volatility

Relationship between germination and bell pepper seed structure assessed by the X-ray test

Alternative use of the X-ray test to evaluate seed quality has become increasingly diverse. This study was performed primarily to establish experimental procedures and verify the effectiveness of the X-ray test to detect damage or abnormalities in bell pepper (Capsicum annuum) seed structure associated with germination. Five seed lots each of hybrids Reinger and Sentinel were used. Two hundred seeds per lot were exposed to durations and intensities of X-radiation and visually classified into four categories according to the proportion between the area occupied by the embryo and endosperm in relation to the total cavity area in the internal seed structure, e.g. 0, < 50%, 50-75% and 100%. The last category was subdivided into two others based on the occurrence of morphological abnormalities. Seed samples obtained from different X-ray categories were then submitted to germination test at 25ºC for 14 days and subsequently compared with results of the X-ray analysis. Exposure to a 10 kV radiation for 260 s was the most suitable X-ray dose for visualizing seed structure. Seeds in which the area of the internal cavity occupied by the embryo and endosperm varied from 50-75% produced abnormal seedlings or did not germinate. Full seeds (100% of the internal cavity area occupied) with abnormal structure usually originated defective seedlings. As a consequence, the classification of bell pepper seeds according to the proportion occupied by the seed content (embryo + endosperm) allowed a reliable estimation of the degree of seed physical integrity based on X-ray analysis and its association with germination performance

Tamanho de amostra-referência para regressão múltipla em milho

The objective of this work was to determine the number of plants required to model corn grain yield (Y) as a function of ear length (X1) and ear diameter (X2), using the multiple regression model Y = β0 + β1X1 + β2X2. The Y, X1, and X2 traits were measured in 361, 373, and 416 plants, respectively, of single-, three-way, and double-cross hybrids in the 2008/2009 crop year; and in 1,777, 1,693, and 1,720 plants, respectively, of single-, three-way, and double-cross hybrids in the 2009/2010 crop year, totaling 6,340 plants. Descriptive statistics were calculated, and frequency histograms and scatterplots were created. The sample size (number of plants) for the estimate of the β0, β1, and β2 parameters, of the residual standard error, the coefficient of determination, the variance inflation factor, and the condition number between the explanatory traits of the model (X1 and X2) were determined by resampling with replacement. Measuring 260 plants is sufficient to adjust precise multiple regression models of corn grain yield as a function of ear length and ear diameter. The Y = -229.76 + 0.54X1 + 6.16X2 model is a reference for estimating corn grain yield.O objetivo deste trabalho foi determinar o número de plantas necessário para modelar a produtividade de grãos de milho (Y) em função do comprimento de espiga (X1) e do diâmetro de espiga (X2), por meio do modelo de regressão múltipla Y = β0 + β1X1 + β2X2. Os caracteres Y, X1 e X2 foram mensurados em 361, 373 e 416 plantas, respectivamente, de híbridos simples, triplo e duplo no ano agrícola 2008/2009; e em 1.777, 1.693 e 1.720 plantas, respectivamente, de híbridos simples, triplo e duplo no ano agrícola 2009/2010, tendo-se totalizado 6.340 plantas. Foram calculadas estatísticas descritivas, e confeccionados histogramas de frequência e diagramas de dispersão. O tamanho de amostra (número de plantas) para a estimação dos parâmetros β0, β1 e β2, do erro-padrão residual, do coeficiente de determinação, do fator de inflação da variância e do número de condição entre os caracteres explicativos do modelo (X1 e X2) foram determinados por reamostragem, com reposição. A mensuração de 260 plantas é suficiente para ajustar modelos de regressão múltipla precisos para produtividade de grãos de milho, em função do comprimento de espiga e do diâmetro de espiga. O modelo Y = -229,76 + 0,54X1 + 6,16X2 é referência para estimar a produtividade de grãos de milho

The Ground of the Universal in the Singular According to Thomas Aquinas: Common Nature, Similitude, and/or Idea?

In this article, I aim to analyze, in Thomas Aquinas’s philosophy, (i) whether the “essence absolutely considered” (or “common nature”) can play a role of ground for the universal in the singular thing or in the individual and (ii) whether it is simultaneously obtained through the intelligible abstraction of the essence with the intention of universality or through a “double abstraction”. Additionally, I will investigate whether the “essence absolutely considered” requires, from Aquinas, an appropriation of a certain theory of ideas, and whether the association between this essence and the ideas is something required to justify the “similitude” among universals and individuals. Finally, I will approach some different receptions of Thomas Aquinas in the 20th and 21st centuries, most of them used to frame his thought under so distinct perspectives, such as of a direct realist, an essentialist, an indirect realist, a representationalist etc