Desvendando os Mistérios do Coeficiente de Correlação de Pearson: o Retorno

Paranhos, Ranulfo; Filho, Dalson Britto Figueiredo; Rocha, Enivaldo Carvalho da; Júnior, José Alexandre da Silva; Neves, Jorge Tadeu de Ramos; Santos, Manoel Leonardo

doi:10.11606/issn.2237-4485.lev.2014.132346

Cited by 70 publications

(57 citation statements)

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“…The correlation between variables by Pearson's coefficient (Table 3) proved to be strong between mammary quarters (0.89; 0.84; 0.91; 0.75; 0.8 and 0.86). According to Figueiredo Filho and Silva Júnior (2009), the closer to 1 the coefficient value (regardless of sign), the higher the degree of statistical dependence between variables. On the other hand, the closer to zero, the weaker the strength of this correlation.…”

Section: Resultsmentioning

confidence: 99%

Exploratory data inference for detecting mastitis in dairy cattle

Silva

Pandorfi

Almeida

et al. 2020

Acta Sci. Anim. Sci.

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The aim of this study was to employ the principal component technique to physiological data and environmental thermohygrometric variables correlated with detection of clinical and subclinical mastitis in dairy cattle. A total of 24 lactating Girolando cows with different clinical conditions were selected (healthy, and with clinical or subclinical mastitis). The following physiological variables were recorded: udder surface temperature, ST (°C); eyeball temperature, ET (°C); rectum temperature, RT (°C); respiratory frequency, RF (mov. min-1). Thermohygrometric variables included air temperature, AirT (°C), and relative humidity, RU (%). ST was determined by means of thermal images, with four images per animal, on these quarters: front left side (FL), front right side (FR), rear right side (RR) and rear left side (RL), totaling 96 images. Exploratory data analysis was run through multivariate statistical technique with the employment of principal components, comprehending nine variables: ST on the FL, FR, RL and RR quarters; ET, RT; RF, AirT and RU. The representative quarters of the animals with clinical and subclinical mastitis showed udder temperatures 8.55 and 2.46° C higher than those of healthy animals, respectively. The ETs of the animals with subclinical and clinical mastitis were, respectively, 7.9 and 8.0% higher than those of healthy animals. Rectum temperatures were 2.9% (subclinical mastitis) and 5.5% (clinical mastitis) higher compared to those of healthy animals. Respiratory frequencies were 40.3% (subclinical mastitis) and 61.6% (clinical mastitis) higher compared to those of healthy animals. The first component explained 91% of the total variance for the variables analyzed. The principal component technique allowed verifying the variables correlated with the animals' clinical condition and the degree of dependence between the study variables.

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Section: Resultsmentioning

confidence: 99%

Exploratory data inference for detecting mastitis in dairy cattle

Silva

Pandorfi

Almeida

et al. 2020

Acta Sci. Anim. Sci.

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“…The Pearson's correlation correct computation and interpretation require that the data be normally distributed and with no outliers (extreme values) [38]; this requirement was achieved ( Table 1). All the correlations observed (Table 3) were signi cant (p < 0.01) and very strong correlations (r > 0.9) according to Callegari-Jacques [39].…”

Section: Resultsmentioning

confidence: 99%

Improving Soybean Production Under Light Supplementation at Field - A Case Study

Lemes

Azevedo

Domiciano

et al. 2020

Preprint

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In modern agriculture, there is a growing need for cropping efficiency e low environmental impacts. Diverse technologies are becoming available in a recent wave of modernization and integration of knowledge. The use of high-efficiency light supplementation to plant development is scarce to high-productive crops at field conditions (outdoor). The objectives of this study were to evaluate soybean plant and yield responses in an open commercial area (field scale) cultivated with artificial light supplementation. A commercial irrigated (pivot) area received an illumination system for light supplementation (LS) in the inner pivot spans. The light applied was a composition of blue, green and red bands. The outer pivot spans did not receive light supplementation (nLS). About 40 hours of LS were applied to the plants during the soybean crop cycle. Internode number, plant height, pods per plant were weekly evaluated to compose the area under the progress curve (AUPC). The grain yield was also evaluated at harvest. Analysis of variance and test of averages were used to evaluate the data. The AUPC of the internode number, plant height and pods per plant were 15.6, 23.3 and 25.3% higher than for the LS treatment. The regular soybean cycle (nLS) was about 17 weeks; however, the harvest of the LS treatment happened three weeks later. The grain productivity of the nLS was about 4,500 kg ha-1 (75 bags), and of the LS treatment was about 7,080 kg ha-1 (118 bags) - 57.3% superior. Light supplementation at field scale is a challenge; however, affordable and field resistant technologies are now accessible. The present study is the first report of light supplementation used to improve soybean crop production at field scale. The possibility of using light regulation as an additional technique for increasing yields and sustainable production are also discussed.

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“…Observa-se correlação negativa e significativa entre a injúria visual (%) e a eficiência quântica do fotossistema II (Fv/Fm) aos 3, 7 e 14 DAA de subdoses de 2,4-D sal colina em algodoeiro nos estádios V4 e B4 para ambos os anos de condução do experimento (Tabela 1). Os valores negativos de correlação indicam que quando uma determinada variável "x" aumenta, a variável correlacionada "y" diminui (PARANHOS et al, 2014). Por conta disso, os resultados dessa pesquisa indicam que à medida que o percentual de injúria visual aumenta, em consequência da aplicação de maiores subdoses do herbicida, a variável Fv/Fm diminui, demonstrando assim danos significativos ao aparato fotoquímico das plantas de algodoeiro.…”

Section: Resultsunclassified

Efeito de subdoses de 2,4-D sal colina na eficiência quântica do fotossistema II do algodoeiro

2020

COLLOQ AGRARIAE

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Deleterious effects of herbicides on the photochemical apparatus of plants can be quantified by studying the quantum yield potential of photosystem II (Fv/Fm). Therefore, the objective of this work was to evaluate the effect of subdoses of the herbicide 2,4-D choline salt formulation on the quantum efficiency of the photosystem II of cotton plantsat different phenological stages. The study adopted a completely randomized experimental design with seven replications, and the treatments consisted of nine fractions of the average rate indicated on the 2,4-D choline salt herbicide label: 0 (control); 0.4275; 0.855; 1.71; 3.42; 8.55; 17.1; 34.2 and 68.4 g ae ha-1applied at phenological stages V4 or B4 of cotton plants. The plants were evaluated for the visual symptoms of injury and the emission kinetics of maximum chlorophyll a (Fv/Fm) fluorescence at 3, 7 and 14 days after application (DAA) of the herbicide. The values obtained were analyzed by the F test and the effects of the treatments were compared by the Scott-Knott test at 5% probability. The data obtained from visual injury and Fv/Fmwere also submitted to Pearson's correlation. The correlation between visual injury and Fv/Fmin the V4 and B4 stages is negative and significant for both years of conducting the experiment. The Fv/Fmvariable was not affected by the application of subdoses lower than 3.42 g aeha-1of 2,4-D saline choline in the V4 stage and below 1.71 g aeha-1in the B4 stage of the cotton plant.

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Desvendando os Mistérios do Coeficiente de Correlação de Pearson: o Retorno

Cited by 70 publications

References 0 publications

Exploratory data inference for detecting mastitis in dairy cattle

Exploratory data inference for detecting mastitis in dairy cattle

Improving Soybean Production Under Light Supplementation at Field - A Case Study

Efeito de subdoses de 2,4-D sal colina na eficiência quântica do fotossistema II do algodoeiro

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