A Note on Normal Correlation

Pitman, E. J. G.

doi:10.1093/biomet/31.1-2.9

Cited by 423 publications

(157 citation statements)

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“…As a total of seven different comparisons were made between the new formula and the traditional equations, a Bonferroni adjustment 22 was carried out and P ≤ 0.007 was regarded as significant. The SDs of PEs of different models were compared using Pitman's test for correlated variance 23,24 . At a significance level of 1% and with a sample size of more than 100, R ≥ 0.254 was significant.…”

Section: Discussionmentioning

confidence: 99%

Macrosomia: a new formula for optimized fetal weight estimation

Hart

Hilbert

Meurer

et al. 2009

Ultrasound in Obstet & Gyne

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Objectives To develop and test a specific formula for estimating weight in the macrosomic fetus. (3.69 (range, 0.05-13.57)%) when studied in the evaluation group. With the new formula, 77.9% of estimates fell within ± 5% of the actual weight at birth, 97.1% within ± 10%, and 100% within ± 15% and ± 20%. Methods ConclusionsThe new formula allows better weight estimation in the macrosomic fetus.

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Section: Discussionmentioning

confidence: 99%

Macrosomia: a new formula for optimized fetal weight estimation

Hart

Hilbert

Meurer

et al. 2009

Ultrasound in Obstet & Gyne

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“…The slopes were calculated as Standardized Major Axes (SMA) . Confidence intervals for individual regression slopes were calculated following Pitman (1939). We followed the methods of Warton and Weber (2002) to test for the heterogeneity of regression slopes and calculated the common slopes when homogeneity of the slopes was demonstrated.…”

Section: Discussionmentioning

confidence: 99%

Testing the generality of the ‘leafing intensity premium’ hypothesis in temperate broad-leaved forests: a survey of variation in leaf size within and between habitats

Sun

2009

Evol Ecol

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Because leaf size scales negatively and isometrically with leaf number per shoot size (leafing intensity) in woody species, and because most tree and shrub species have small leaves, Kleiman and Aarssen (J Ecol 95:376-382, 2007) recently proposed that natural selection favors high leafing intensity resulting in small leaves, i.e., the leafingintensity-premium hypothesis. However, empirical evidence for or against this hypothesis is still lacking. In addition, this hypothesis has not been examined in the context of how leaf size varies among habitats. To fill this void, we investigated leaf size frequency distributions of woody species from temperate China and explored the relationships among leaf mass, leaf number, and stem mass of current-year shoots of 133 woody species at low and high altitudes of three mountain ranges. The scaling relationships between leaf size and leafing intensity (leaf number per stem mass) were determined using both standardized major axis regression analyses and phylogenetically independent comparative techniques. In light of the leafing-intensity-premium hypothesis, we made three predictions: (1) leaf size frequency distributions should be right-skewed for each local study area and for the entire study region, (2) leafing intensities at different altitudes at different sites should differ while leafing intensities at comparable altitudes should be similar baring large taxonomic differences among sites, and (3) that leafing intensity should be higher for any given leaf size in habitats with small-leaved species. Significant negative and isometric scaling relationships between leaf size and leafing intensity were found to be consistently conserved independent of habitat type, both across species and across correlated evolutionary divergences. Within each mountain range or across the entire study region, leaf size frequency distributions were right-skewed, in accordance with our prediction. However, leafing intensity was smaller for any given leaf size at the altitude with smaller leafed 123Evol Ecol (2010) 24:685-701 DOI 10.1007 species than for altitudes characterized by large leafed species, i.e., altitudes characterized by species with small leaves did not have consistently higher leafing intensities than other altitudes on each mountain range. Our analyses therefore indicate the direct adaptive value of leaf size but not the selective advantage in high leafing intensity as posited by the leafing-intensity-premium hypothesis. We suggest that this hypothesis explains less about the variation of leaf size among different habitats as it does about variation within habitats, i.e., the relative importance of the adaptive significance of leafing intensity and leaf size can and does vary with habitats.

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“…The Bland-Altman method is supplemented with a more formal test, Pitman's test of difference in variance (Pitman, 1939;Snedecor & Cochran, 1967), which compares two correlated variances in paired samples to test the degree of agreement between the conventional and alternative methods for measuring crop areas. The results of this test are reported in Table 3 for all of the crops considered.…”

Section: Comparing Methods Of Measurementmentioning

confidence: 99%

Using geospatial technology to strengthen data systems in developing countries: The case of agricultural statistics in India

Naik¹,

Basavaraj²,

Hegde³

et al. 2013

Applied Geography

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ABSTRACT. Despite significant progress in the development of quantitative geography techniques and methods and a general recognition of the need to improve the quality of geographic data, few studies have exploited the potential of geospatial tools to augment the quality of available data methods in developing countries. This paper uses data from an extensive deployment of geospatial technology in India to compare crop areas estimated using geospatial technology to crop areas estimated by conventional methods and assess the differences between the methods. The results presented here show that crop area estimates based on geospatial technology generally exceed the estimates obtained using conventional methods. This suggests that conventional methods are unable to respond quickly to changes in cropping patterns and therefore do not accurately record the area under high-value cash crops. This finding has wider implications for commercializing agriculture and the delivery of farm credit and insurance services in developing countries. Significant data errors found in the conventional methods could affect critical policy interventions such as planning for food security. Some research and policy implications are discussed.

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A Note on Normal Correlation

Cited by 423 publications

References 0 publications

Macrosomia: a new formula for optimized fetal weight estimation

Macrosomia: a new formula for optimized fetal weight estimation

Testing the generality of the ‘leafing intensity premium’ hypothesis in temperate broad-leaved forests: a survey of variation in leaf size within and between habitats

Using geospatial technology to strengthen data systems in developing countries: The case of agricultural statistics in India

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