scholarly journals Gametic Disequilibrium Measures: Proceed With Caution

Genetics ◽  
1987 ◽  
Vol 117 (2) ◽  
pp. 331-341 ◽  
Author(s):  
Philip W Hedrick
Keyword(s):  
Correlation Coefficient ◽  
Hot Spots ◽  
Population Bottlenecks ◽  
Frequency Dependent ◽  
Gametic Disequilibrium ◽  
Allelic Frequencies ◽  
Highly Correlated ◽  
Rates Of Decay

ABSTRACT Five different measures of gametic disequilibrium in current use and a new one based on R. C. Lewontin's D′, are examined and compared. All of them, except the measure based on Lewontin's D′, are highly dependent upon allelic frequencies, including four measures that are normalized in some manner. In addition, the measures suggested by A. H. D. Brown, M. F. Feldman and E. Nevo, and T. Ohta can have negative values when there is maximum disequilibrium and have rates of decay in infinite populations that are a function of the initial gametic array. The variances were large for all the measures in samples taken from populations at equilibrium under neutrality, with the measure based on D′ having the lowest variance. In these samples, three of the measures were highly correlated, D2, D* (equal to the correlation coefficient when there are two alleles at each locus) and the measure X(2) of Brown et al. Using frequency-dependent measures may result in mistaken conclusions, a fact illustrated by discussion of studies inferring recombinational hot spots and the effects of population bottlenecks from disequilibrium values.

scholarly journals OP0178 IMAGING NEOANGIOGENESIS IN RHEUMATOID ARTHRITIS (INIRA): WHOLE-BODY SYNOVIAL UPTAKE OF A 99MTC-LABELLED RGD PEPTIDE IS HIGHLY CORRELATED WITH POWER DOPPLER ULTRASOUND

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 110.2-111
Author(s):  
L. Attipoe ◽  
S. Subesinghe ◽  
C. Blanco-Gil ◽  
M. Opena ◽  
M. Rosser ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Correlation Coefficient ◽  
Doppler Ultrasound ◽  
Imaging Modality ◽  
Power Doppler ◽  
Whole Body ◽  
Total Power ◽  
Acquisition Time ◽  
Power Doppler Ultrasound ◽  
Highly Correlated

Background:Power Doppler ultrasound (PDUS) is superior to clinical examination in detecting synovitis in patients with rheumatoid arthritis (RA). Although dynamic and cheap it is impractical to scan large numbers of joints in routine clinical settings. MRI, whilst sensitive for synovitis, is expensive and routine use is limited to targeted joints. Bone scintigraphy produces whole body images but due to limited specificity is not routinely used.99mTc-maraciclatide (Serac Healthcare) is a radiolabelled tracer which binds with high affinity to integrin αvβ3, a cell-adhesion molecule up-regulated on neoangiogenic blood vessels. It therefore has the potential to image synovial inflammation at the whole-body level. We previously showed in a pilot study that uptake was seen in the inflamed joints of five RA patients and that this correlated with PDUS. This study explores correlation with PDUS in a larger groups of patients with varied disease activity.Objectives:To determine the correlation between ultrasound and99mTc-maraciclatide imaging in patients with rheumatoid arthritis.Methods:50 patients with RA fulfilling ACR 2010 classification criteria were recruited. Patients underwent an ultrasound scan of 40 joints with grey scale (GS) and PD quantification. Each joint was scored on a scale of 0-3 for GS and PD with a total score calculated for each patient. Within 3 hours of the ultrasound patients were injected with 740 MBq of99mTc-maraciclatide. Using a gamma camera, whole body planar views and dedicated hand and foot views were taken 2 hours after injection (Figure 1). Acquisition time was 20 minutes for whole body and 20 minutes for hand and foot views.99mTc-maraciclatide images were scored as positive or negative uptake for each joint (binary score). A quantitative score was also calculated for each joint where there was uptake with this corrected for background uptake. Total binary and quantitative scores per patient were calculated.Ultrasound and99mTc-maraciclatide scores were tested for correlation with Pearson’s correlation coefficient (r). Interrater agreement for 2 scorers was calculated using kappa (ĸ) and concordance correlation coefficient (Pc).Results:Strong correlation was seen when total PDUS was compared to binary scores (r=0.92, r2=0.85) (Figure 2) and quantitative scores (r=0.85, r2=0.72). ĸ was 0.82 and 0.79 for binary and ultrasound scores respectively.Pcwas 0.82 for quantitative scores. p was <0.0005 for all results.99mTc-maraciclatide uptake was also seen in inflamed tendons/tendon sheaths. The imaging procedure was well-tolerated. There were no tracer-related adverse events.Figure 1.99mTc-maraciclatide imaging with dedicated hand and foot viewsConclusion:99mTc-maraciclatide uptake was highly correlated with PDUS highlighting its potential as an alternative imaging modality.99mTc-based planar imaging has the unique capacity to image the whole body and hence the total synovial inflammatory load in a quick acquisition. The imaging equipment to perform these scans is already widely available in radiology departments. Interpretation of scans is also much simpler compared to US/MRI. It could therefore have a role in key decision-making points in pathways for diagnosis, treatment failure, and remission prior to dose tapering.Figure 2.Correlation between total power doppler and99mTc-maraciclatide binary scoresDisclosure of Interests:None declared

Relationships between body weight and some follicle and fleece characters in an Australian fine-wool Merino flock

1969 ◽  
Vol 20 (6) ◽  
pp. 1177 ◽  
Author(s):  
T Nay ◽  
RH Hayman
Keyword(s):  
Body Weight ◽  
Correlation Coefficient ◽  
Unit Area ◽  
Additive Effect ◽  
Phenotypic Correlations ◽  
Close Relationship ◽  
Simultaneous Selection ◽  
Selection For ◽  
Fleece Weight ◽  
Highly Correlated

Phenotypic correlations between body weight, follicle characters, and fleece characters have been investigated in a flock of 95 fine-wool non-Peppin Merino wethers, reared in the same locality under the same conditions. The results indicated that three follicle characters, follicle chord, follicle depth, and the index of follicle bending, were independent of body weight. It was found, in agreement with the results of other workers, that body weight was highly correlated with both greasy and clean wool weights (r = 0.53 and 0.51 respectively). It was also found that follicle characters were significantly correlated with most of the fleece characters which contribute to the clean fleece weight per unit area of skin. The correlation coefficient of wool weight per unit area of skin with follicle chord was 0.33, with follicle depth 0.28, and with follicle bending index –0.35. The follicle characters were also correlated with greasy and clean fleece weights. Crimp number per inch was predicted for individual animals by using as criterion the length of the follicle chord. A highly significant correlation coefficient of 0.67 was obtained between predicted and observed crimp number. The close relationship between crimp chord and follicle chord reported in previous work was confirmed. It is suggested that simultaneous selection for body weight and certain follicle characters may have an additive effect on the production of clean wool. It is also suggested that the genetic antagonism between clean wool weight and number of crimps per inch can be explained in anatomical terms.

Breed and environmental effects on lamb production in Nigeria

1981 ◽  
Vol 96 (1) ◽  
pp. 9-15 ◽  
Author(s):  
V. Buvanendran ◽  
I. F. Adu ◽  
B. A. Oyejola
Keyword(s):  
Body Weight ◽  
Environmental Factors ◽  
Least Squares ◽  
Correlation Coefficient ◽  
Environmental Effects ◽  
Correlation Coefficients ◽  
Correction Factors ◽  
The Cross ◽  
Highly Correlated ◽  
Least Squares Estimates

SUMMARYTwo indigenous breeds of sheep in Nigeria, the Yankasa and Uda and crosses of these with exotic breeds, were evaluated for lamb weights at birth, 3 months and 6 months of age and for adult ewe weight. The cross-bred lambs were significantly (P < 0·05) heavier than the indigenous breeds at all ages. Differences among the indigenous breeds were not significant. Mature ewe weight was 40·8 kg in the cross-bred and 36·0 and 31·1 kg in the Uda and Yankasa respectively, differences between all breeds being significant (P <0·05). Lamb productivity (lamb weight per kg of ewe metabolic body weight) estimates demonstrated that the differences between breeds were small.Least-squares estimates of effects of environmental factors on lamb performance showed that type of birth and age of dam were important for lamb weights at the three ages. Season and sex also had significant effects on birth and 6-month weights respectively. Correction factors for lamb weights were derived from least-squares estimates.The correlation coefficient between birth and 3-month weight was significant in all breeds and ranged from 0·39 to 0·55. Three-month and 6-month weights were highly correlated with estimates of correlation coefficients ranging from 0·71 to 0·74. Repeatability estimates of birth, 3·month, 6·month and ewe weights, all as traits of the ewe in the Yankasa, were 0·25, 0·21, 0·09 and 0·48, respectively.

scholarly journals Electrocardiographic Imaging of Repolarization Abnormalities

2021 ◽  
Vol 10 (9) ◽  
Author(s):  
Laura R. Bear ◽  
Matthijs Cluitmans ◽  
Emma Abell ◽  
Julien Rogier ◽  
Louis Labrousse ◽  
...  
Keyword(s):  
Sinus Rhythm ◽  
Correlation Coefficient ◽  
Ex Vivo ◽  
Data Sets ◽  
Human Donor ◽  
Electrocardiographic Imaging ◽  
Significant Difference ◽  
Highly Correlated ◽  
Repolarization Abnormalities

Background Dispersion and gradients in repolarization have been associated with life‐threatening arrhythmias, but are difficult to quantify precisely from surface electrocardiography. The objective of this study was to evaluate electrocardiographic imaging (ECGI) to noninvasively detect repolarization‐based abnormalities. Methods and Results Ex vivo data were obtained from Langendorff‐perfused pig hearts (n=8) and a human donor heart. Unipolar electrograms were recorded simultaneously during sinus rhythm from an epicardial sock and the torso‐shaped tank within which the heart was suspended. Regional repolarization heterogeneities were introduced through perfusion of dofetilide and pinacidil into separate perfusion beds. In vivo data included torso and epicardial potentials recorded simultaneously in anesthetized, closed‐chest pigs (n=5), during sinus rhythm, and ventricular pacing. For both data sets, ECGI accurately reconstructed T‐wave electrogram morphologies when compared with those recorded by the sock (ex vivo: correlation coefficient, 0.85 [0.52–0.96], in vivo: correlation coefficient, 0.86 [0.52–0.96]) and repolarization time maps (ex‐vivo: correlation coefficient, 0.73 [0.63–0.83], in vivo: correlation coefficient, 0.76 [0.67–0.82]). ECGI‐reconstructed repolarization time distributions were strongly correlated to those measured by the sock (both data sets, R 2 ≥0.92). Although the position of the gradient was slightly shifted by 8.3 (0–13.9) mm, the mean, max, and SD between ECGI and recorded gradient values were highly correlated ( R 2 =0.87, 0.75, and 0.86 respectively). There was no significant difference in ECGI accuracy between ex vivo and in vivo data. Conclusions ECGI reliably and accurately maps potentially critical repolarization abnormalities. This noninvasive approach allows imaging and quantifying individual parameters of abnormal repolarization‐based substrates in patients with arrhythmogenesis, to improve diagnosis and risk stratification.

scholarly journals The statistical studies of the inner boundary of plasma sheet

2011 ◽  
Vol 29 (2) ◽  
pp. 289-298 ◽  
Author(s):  
J. B. Cao ◽  
W. Z. Ding ◽  
H. Reme ◽  
I. Dandouras ◽  
M. Dunlop ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Plasma Sheet ◽  
Radial Distance ◽  
Correlation Coefficients ◽  
Geosynchronous Orbit ◽  
Direct Observations ◽  
The Earth ◽  
Night Side ◽  
Statistical Studies ◽  
Highly Correlated

Abstract. The penetration of plasma sheet ions into the inner magnetosphere is very important to the inner magnetospheric dynamics since plasma sheet ions are one of the major particle sources of ring current during storm times. However, the direct observations of the inner boundary of the plasma sheet are fairly rare due to the limited number of satellites in near equatorial orbits outside 6.6 RE. In this paper, we used the ion data recorded by TC-1 from 2004 to 2006 to study the distribution of inner boundary of ion plasma sheet (IBIPS) and for the first time show the observational distribution of IBIPS in the equatorial plane. The IBIPS has a dawn-dusk asymmetry, being farthest to the Earth in the 06:00 08:00 LT bin and closest to the Earth in the 18:00–20:00 LT bin. Besides, the IBIPS has also a day-night asymmetry, which may be due to the fact that the ions on the dayside are exposed more time to loss mechanisms on their drift paths. The radial distance of IBIPS decrease generally with the increase of Kp index. The mean radial distance of IBIPS is basically larger than 6.6 RE during quiet times and smaller than 6.6 RE during active times. When the strength of convection electric field increases, the inward shift of IBIPS is most significant on the night side (22:00–02:00 LT). For Kp ≤ 0+, only 16% of IBIPSs penetrate inside the geosynchronous orbit. For 2 ≤ Kp < 3+, however, 70% of IBIPSs penetrate inside the geosynchronous orbit. The IBIPS has weak correlations with the AE and Dst indexes. The average correlation coefficient between Ri and Kp is −0.58 while the correlation coefficient between Ri and AE/Dst is only −0.29/0.17. The correlation coefficients are local time dependent. Particularly, Ri and Kp are highly correlated (r=−0.72) in the night sector, meaning that the radial distance of IBIPS Ri in the night sector has the good response to the Kp index These observations indicate that Kp plays a key role in determining the position of IBIPS.

scholarly journals Multi-genre Movie Data Analysis Using Pearson's Correlation

2019 ◽  
pp. 881-887
Author(s):  
Shalini Mounika Maturu ◽  
Tamma Eekshitha ◽  
Talla Ramya ◽  
Tulluru Thanmai Durga
Keyword(s):  
Data Analysis ◽  
Correlation Coefficient ◽  
Statistical Technique ◽  
Success Prediction ◽  
Pearson’S Correlation ◽  
Pearson’S Correlation Coefficient ◽  
Single Attribute ◽  
Pearson's Correlation ◽  
Multiple Attributes ◽  
Highly Correlated

The success of a movie plays an important role because it usually involves huge amounts of investments. Thus it becomes important to know beforehand whether the movie will be successful or not. The aim of our work is to prove that various attributes or factors related to a movie could prove useful in predicting the success or failure of a movie. Since one single attribute is not sufficient to predict the success of a movie, we’ve used multiple attributes and the comparisons between various attributes and their correlation for the success prediction. Therefore, in this paper we are considering a statistical technique called Pearson’s correlation coefficient in finding out which factors are highly correlated with a movie’s ratings.

scholarly journals MULTIVARIATE ANALYSIS OF GAMETIC DISEQUILIBRIUM IN THE YANOMAMA

Genetics ◽  
1977 ◽  
Vol 85 (4) ◽  
pp. 733-752
Author(s):  
Peter E Smouse ◽  
James V Neel
Keyword(s):  
Territorial Expansion ◽  
Single Measure ◽  
Gametic Disequilibrium ◽  
Multiple Locus ◽  
Multivariate Correlation ◽  
Tight Linkage ◽  
Fusion Mode ◽  
Highly Correlated ◽  
Weinberg Expectation ◽  
Gametic Disequilibria

ABSTRACT The gametic disequilibria between all possible pairs of loci were examined for a set of eight codominant loci in each of fifty Yanomama villages, using a multivariate correlation analysis which reduces the results to a single measure of departure from multiple-locus-gametic equilibrium. Thirty-two of the fifty villages departed significantly from multiple-locus gametic equilibrium. The largest contributions to the departure from multiple-locus equilibrium were due to the disequilibria between MN and Ss and between Rh(Cc) and Rh(Ee), indicating the effects of tight linkage. After removing the effects of these obvious sources of disequilibrium, sixteen of the fifty villages still remained significantly out of equilibrium. The disequilibrium between any particular pair of loci was highly erratic from village to village, and (with the exception of the MN-Ss and Cc-Ee disequilibria) averaged out very close to zero overall, suggesting a lack of systematic forces (epistatic selection). The departure from equilibrium in any one village is in excess of that expected from random sampling alone, and is attributed primarily to the fission-fusion mode of village formation operative in the Yanomama and the fact that a single village consists of a few extended lineages. Village allele frequencies are highly correlated across loci, and most of the non-independence is accounted for by large correlations in the average allelic frequencies of different loci for related villages. It is suggested that these correlations also are due to territorial expansion and population growth. For the tribe as a whole, all but the tightly linked markers of the MNSs and Rh complexes are approximately uncorrelated, and large departures from multiple-locus Hardy-Weinberg expectation are primarily due to substantial Wahlund variance within the tribe. There is no need to postulate a role for selection in these disequilibria.

scholarly journals Exploring the Applicability and Scaling Effects of Satellite-Observed Spring and Autumn Phenology in Complex Terrain Regions Using Four Different Spatial Resolution Products

2021 ◽  
Vol 13 (22) ◽  
pp. 4582
Author(s):  
Fangxin Chen ◽  
Zhengjia Liu ◽  
Huimin Zhong ◽  
Sisi Wang
Keyword(s):  
Correlation Coefficient ◽  
Loess Plateau ◽  
Spatial Resolution ◽  
Land Surface ◽  
Remote Sensing Data ◽  
Growing Season ◽  
Scaling Effects ◽  
Modis Ndvi ◽  
Phenological Changes ◽  
Highly Correlated

The information on land surface phenology (LSP) was extracted from remote sensing data in many studies. However, few studies have evaluated the impacts of satellite products with different spatial resolutions on LSP extraction over regions with a heterogeneous topography. To bridge this knowledge gap, this study took the Loess Plateau as an example region and employed four types of satellite data with different spatial resolutions (250, 500, and 1000 m MODIS NDVI during the period 2001–2020 and ~10 km GIMMS3g during the period 1982–2015) to investigate the LSP changes that took place. We used the correlation coefficient (r) and root mean square error (RMSE) to evaluate the performances of various satellite products and further analyzed the applicability of the four satellite products. Our results showed that the MODIS-based start of the growing season (SOS) and end of the growing season (EOS) were highly correlated with the ground-observed data with r values of 0.82 and 0.79, respectively (p < 0.01), while the GIMMS3g-based phenology signal performed badly (r < 0.50 and p > 0.05). Spatially, the LSP that was derived from the MODIS products produced more reasonable spatial distributions. The inter-annual averaged MODIS SOS and EOS presented overall advanced and delayed trends during the period 2001–2020, respectively. More than two-thirds of the SOS advances and EOS delays occurred in grasslands, which determined the overall phenological changes across the entire Loess Plateau. However, both inter-annual trends of SOS and EOS derived from the GIMMS3g data were opposite to those seen in the MODIS results. There were no significant differences among the three MODIS datasets (250, 500, and 1000 m) with regard to a bias lower than 2 days, RMSE lower than 1 day, and correlation coefficient greater than 0.95 (p < 0.01). Furthermore, it was found that the phenology that was derived from the data with a 1000 m spatial resolution in the heterogeneous topography regions was feasible. Yet, in forest ecosystems and areas with an accumulated temperature ≥10 °C, the differences in phenological phase between the MODIS products could be amplified.

scholarly journals Wastewater-based epidemiology predicts COVID-19 community prevalence

2021 ◽  
Author(s):  
Tyler Radniecki ◽  
Blythe Layton ◽  
Devrim Kaya ◽  
Christine Kelly ◽  
Kenneth Williamson ◽  
...  
Keyword(s):  
Hot Spots ◽  
Disease Burden ◽  
Individual Level ◽  
Public Health Systems ◽  
Prevalence Estimates ◽  
Systematic Biases ◽  
Neighborhood Scale ◽  
Highly Correlated ◽  
Labor Requirements ◽  
Wastewater Samples

Abstract Wastewater-based epidemiology uses pooled wastewater samples to monitor community health and has been used extensively during the COVID-19 pandemic to track SARS-CoV-2 RNA shed by infected individuals into wastewater. Wastewater concentrations of SARS-CoV-2 RNA have been positively correlated with contemporaneous counts of COVID-19 cases, making it useful for following relative disease burden trends within a community. However, the statistical associations are too weak for wastewater-based epidemiology to reliably predict reported case counts, limiting its potential. Here we show that wastewater SARS-CoV-2 concentrations are highly correlated with the community prevalence estimated from 8 randomized household community surveys in 6 Oregon communities over a 10-month period. We found that wastewater-based epidemiology is a significantly better predictor of COVID-19 community prevalence than reported case counts, which suffer from systematic biases including variations in access to testing and underreporting of asymptomatic cases, even after accounting for uncertainty inherent in the wastewater and prevalence estimates by using Monte Carlo simulations. Additionally, our results show that wastewater-based epidemiology can identify the rise and fall of neighborhood-scale COVID-19 hot spots and provide rapid information about the presence of SARS-CoV-2 variants at the neighborhood- and city-scale through sequence analyses of the wastewater. These results validate the potential of wastewater-based epidemiology to be a quantitative method to predict the prevalence of SARS-CoV-2 and identify the presence of variants of concern in a given community or neighborhood, independent of availability and access to individual-level testing. These advantages in combination with its scalability, relatively modest cost and low labor requirements, makes integrating permanent wastewater-based epidemiology infrastructure into public health systems a key component in creating pandemic-resilient cities in the future.

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