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 Analysis of Multilocus Zygotic Associations

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 435-445 ◽  
Author(s):  
Rong-Cai Yang
Keyword(s):  
Effective Means ◽  
Complete Characterization ◽  
Comparative Assessment ◽  
Test Procedures ◽  
Gametic Disequilibrium ◽  
Joint Distributions ◽  
Multiple Loci ◽  
Demographic Processes ◽  
Gametic Disequilibria

Abstract While nonrandom associations between zygotes at different loci (zygotic associations) frequently occur in Hardy-Weinberg disequilibrium populations, statistical analysis of such associations has received little attention. In this article, we describe the joint distributions of zygotes at multiple loci, which are completely characterized by heterozygosities at individual loci and various multilocus zygotic associations. These zygotic associations are defined in the same fashion as the usual multilocus linkage (gametic) disequilibria on the basis of gametic and allelic frequencies. The estimation and test procedures are described with details being given for three loci. The sampling properties of the estimates are examined through Monte Carlo simulation. The estimates of three-locus associations are not free of bias due to the presence of two-locus associations and vice versa. The power of detecting the zygotic associations is small unless different loci are strongly associated and/or sample sizes are large (>100). The analysis of zygotic associations not only offers an effective means of packaging numerous genic disequilibria required for a complete characterization of multilocus structure, but also provides opportunities for making inference about evolutionary and demographic processes through a comparative assessment of zygotic association vs. gametic disequilibrium for the same set of loci in nonequilibrium populations.

scholarly journals Dynamics of gametic disequilibria between loci linked to chromosome inversions: the recombination-redistributing effect of inversions

1996 ◽  
Vol 67 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Arcadio Navarro ◽  
Esther Betrán ◽  
Carlos Zapata ◽  
Alfredo Ruiz
Keyword(s):  
Initial Conditions ◽  
Linkage Equilibrium ◽  
Simulation Studies ◽  
Gametic Disequilibrium ◽  
Practical Applications ◽  
Local Maxima ◽  
Chromosome Inversions ◽  
Chromosome Arrangements ◽  
Recursive Equations ◽  
Gametic Disequilibria

SummaryThe total gametic disequilibrium between two loci linked to polymorphic inversions can be partitioned into two types of components: within and between chromosome arrangements. The within components depend on the gametic disequilibrium within each chromosome arrangement. The between components depend on the locus-inversion disequilibria. This partitioning has practical applications and is indispensable for studying the dynamics of these systems because inversions greatly reduce recombination in the heterokaryotypes while allowing free, and sometimes different, recombination in each of the homokaryotypes. We provide equations for the per generation change of the various disequilibria for systems with two and three chromosome arrangements, and the general recursive equations predicting the disequilibria after any number of generations for the case of two arrangements. Simulation studies were carried out using different values of the recombination parameters and all possible initial conditions. The results show a complex convergence to linkage equilibrium in inversion systems. The various disequilibria can have local maxima and minima while approaching equilibrium and, moreover, their dynamics cannot be described, in general, using a single parameter, i.e. an effective recombination rate. We conclude that the effects of inversions on gametic disequilibria must be carefully considered when dealing with disequilibriain inversion systems. The formulae provided in this paper can be used for such purpose.

Which Performance Measures Do Investors Around the World Value the Most—and Why?

2010 ◽  
Vol 85 (3) ◽  
pp. 753-789 ◽  
Author(s):  
Jan Barton ◽  
Thomas Bowe Hansen ◽  
Grace Pownall
Keyword(s):  
Performance Measures ◽  
Value Relevance ◽  
Earnings Quality ◽  
Cash Flows ◽  
Performance Measure ◽  
Single Measure ◽  
Operating Cash Flows ◽  
The World ◽  
Principal Factors ◽  
Highly Correlated

ABSTRACT: We examine the value relevance of a comprehensive set of summary performance measures including sales, earnings, comprehensive income, and operating cash flows. We find that, while value relevance peaks for measures “above the line,” no single measure dominates around the world. Instead, a measure is more relevant when it captures, directly and quickly, information about firms’ cash flows. Specifically, for each performance measure by country, we estimate eight attributes commonly used to assess earnings quality. We find these attributes highly correlated—most of their variance is explained by only two principal factors. A factor capturing articulation with cash flows is positively associated with a measure’s value relevance; a factor reflecting the measure’s persistence, predictability, smoothness, and conservatism is negatively associated. Our results suggest that, when it comes to equity valuation, accounting researchers and standard-setters should focus not on what performance measure is “best” at a given point in time, but on the underlying attributes that investors find most relevant.

Redundancy of Variables Used to Describe Importance of Prey Species in Fish Diets

1983 ◽  
Vol 40 (5) ◽  
pp. 635-637 ◽  
Author(s):  
J. Stevenson Macdonald ◽  
R. H. Green
Keyword(s):  
Prey Species ◽  
Principal Component ◽  
Food Habit ◽  
Demersal Fish ◽  
Bay Of Fundy ◽  
Fish Food ◽  
Single Measure ◽  
New Information ◽  
Highly Correlated ◽  
Species Importance

Information redundancy associated with three measurement variables were examined using food habit data from five species of demersal fish in the lower Bay of Fundy. Number, weight, and percent frequency of occurrence measures of three prey species all load heavily on the first principal component of a PCA and are therefore highly correlated. We conclude that it is probably not necessary to create compound indices of prey species importance when documenting soft-bottom benthic associations or demersal fish food habits. Compound indices add little new information when compared with any single measure.

Availability of magnesium in soils

1972 ◽  
Vol 79 (2) ◽  
pp. 197-204 ◽  
Author(s):  
A. M. Alston
Keyword(s):  
Activity Ratio ◽  
Significant Proportion ◽  
Parent Material ◽  
Single Measure ◽  
Exchangeable Bases ◽  
Soil Solutions ◽  
Ion Activity ◽  
Activity Ratios ◽  
Highly Correlated ◽  
Better Than

SUMMARYTwenty-five soils, including some subsoils, with widely differing properties were cropped with perennial ryegrass in the glasshouse, and measures of Mg availability in the soils were related to the Mg concentration in the plants.No single measure satisfactorily characterized Mg availability. The ion activity ratio, √aMg/√aca+Mg when the soil neither gained nor lost Mg on equilibration with 0–02 N-CaC12, was more highly correlated (r = 0·;75***) with Mg concentration in the ryegrass than was the best of the capacity measures tested (CaCl2-extractable Mg, r = 0·68***), particularly if the potential buffering capacity (PBCMg) of the soils was also taken into account, in which case r = 0·83***.Exchangeable Mg (r = 0·67***) was a poorer index of Mg availability than percentage Mg saturation (r = 0·73***) or exchangeable Mg expressed as a percentage of the total exchangeable bases (K, Na, Ca and Mg) in the soil (r = 0·81***). This latter quantity was better than the activity ratio as a predictor of Mg availability (r = 0·81*** compared with r = 0·75***).A significant proportion of the variation in Mg concentration in the ryegrass could be attributed to the K content of the soils, and closer correlations were obtained when K was included in the composite activity ratio, √aMg/(√aca+Mg + B. aK) (r = 0·88***) or when a term for exchangeable K was included in regression analysis with √aMg/√aca+Mg and PBCMg (r = 0·93***).The concentration of Mg in equilibrium soil solutions was generally a less satisfactory indicator of Mg availability than were the activity ratios. Soils derived from basaltic parent material had much higher contents of readily exchangeable Mg than the remainder: parent materials other than basalt had little influence on the availability of Mg in the soils. Exchangeable Mg and per cent Mg saturation were higher in gleyed soils than in freely drained soils derived from similar parent material.

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.

Cannabis use in Switzerland: The role of attribution of drug use to friends, urbanization and repression 1The study was supported by the Swiss Federal Office of Public Health (Bundesamt für Gesundheit BAG) Grant 316.96.5980.

2001 ◽  
Vol 60 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Holger Schmid
Keyword(s):  
Drug Use ◽  
Urban Areas ◽  
Hierarchical Linear Model ◽  
Cannabis Use ◽  
School Aged Children ◽  
Structural Variables ◽  
Hbsc Study ◽  
Nationally Representative ◽  
Highly Correlated ◽  
Individual Use

Cannabis use does not show homogeneous patterns in a country. In particular, urbanization appears to influence prevalence rates, with higher rates in urban areas. A hierarchical linear model (HLM) was employed to analyze these structural influences on individuals in Switzerland. Data for this analysis were taken from the Switzerland survey of Health Behavior in School-Aged Children (HBSC) Study, the most recent survey to assess drug use in a nationally representative sample of 3473 15-year-olds. A total of 1487 male and 1620 female students indicated their cannabis use and their attributions of drug use to friends. As second level variables we included address density in the 26 Swiss Cantons as an indicator of urbanization and officially recorded offences of cannabis use in the Cantons as an indicator of repressive policy. Attribution of drug use to friends is highly correlated with cannabis use. The correlation is even more pronounced in urban Cantons. However, no association between recorded offences and cannabis use was found. The results suggest that structural variables influence individuals. Living in an urban area effects the attribution of drug use to friends. On the other hand repressive policy does not affect individual use.

The Difficulties in Emotion Regulation Scale (DERS)

2013 ◽  
Vol 72 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Elise S. Dan-Glauser ◽  
Klaus R. Scherer
Keyword(s):  
Emotion Regulation ◽  
Well Being ◽  
French Translation ◽  
French Version ◽  
Inappropriate Behaviors ◽  
Initial Validation ◽  
Difficulties In Emotion Regulation ◽  
Instrument Measuring ◽  
Highly Correlated ◽  
Psychopathological Disorders

Successful emotion regulation is a key aspect of efficient social functioning and personal well-being. Difficulties in emotion regulation lead to relationship impairments and are presumed to be involved in the onset and maintenance of some psychopathological disorders as well as inappropriate behaviors. Gratz and Roemer (2004 ) developed the Difficulties in Emotion Regulation Scale (DERS), a comprehensive instrument measuring emotion regulation problems that encompasses several dimensions on which difficulties can occur. The aim of the present work was to develop a French translation of this scale and to provide an initial validation of this instrument. The French version was created using translation and backtranslation procedures and was tested on 455 healthy students. Congruence between the original and the translated scales was .98 (Tucker’s phi) and internal consistency of the translation reached .92 (Cronbach’s α). Moreover, test-retest scores were highly correlated. Altogether, the initial validation of the French version of the DERS (DERS-F) offers satisfactory results and permits the use of this instrument to map difficulties in emotion regulation in both clinical and research contexts.

Automated Latex Agglutination and ELISA Testing Yield Equivalent D-Dimer Results in Patients with Recent Myocardial Infarction

1999 ◽  
Vol 82 (11) ◽  
pp. 1412-1416 ◽  
Author(s):  
Wojciech Zareba ◽  
John Horan ◽  
Arthur Moss ◽  
Joel Kanouse ◽  
◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Elisa Test ◽  
Mean Value ◽  
Latex Agglutination ◽  
Test Results ◽  
Coronary Death ◽  
Elisa Testing ◽  
Strong Linear Correlation ◽  
Highly Correlated ◽  
D Dimer

SummaryOur previous prospective study of post-infarction patients described a strong and significant association of increased plasma D-dimer concentrations in those who experienced a subsequent coronary death or non-fatal myocardial infarction. In the present study, we compare results on stored plasma obtained two months after the index myocardial infarction from 1,038 patients of this trial, using a simple automated latex agglutination (LA) assay in parallel with the standard ELISA test. Results show a somewhat higher mean value for the LA assay (702 ± 1092 vs. 638 ± 986 ng/ml, p = 0.0002), a strong linear correlation of the two assays (r = 0.86) and 88% agreement for values below 500 ng/ml by the ELISA test. D-dimer concentrations determined by each assay were highly correlated in patients with subsequent coronary artery events (p = 0.93) and quartile values for both the LA and ELISA were equally predictive of such events (p = 0.003 and p = 0.001, respectively). This is the first demonstration that a latex agglutination assay for D-dimer can be used to assess the prognostic risk of recurrent coronary thrombotic disease after myocardial infarction

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