Decomposition of the difference between two rates and its consistency when more than two populations are involved

1991 ◽  
Vol 3 (2) ◽  
pp. 105-125 ◽  
Author(s):  
Prithwis Das Gupta
2000 ◽  
Vol 25 (2) ◽  
pp. 101-132 ◽  
Author(s):  
András Vargha ◽  
Harold D. Delaney

McGraw and Wong (1992) described an appealing index of effect size, called CL, which measures the difference between two populations in terms of the probability that a score sampled at random from the first population will be greater than a score sampled at random from the second. McGraw and Wong introduced this "common language effect size statistic" for normal distributions and then proposed an approximate estimation for any continuous distribution. In addition, they generalized CL to the n-group case, the correlated samples case, and the discrete values case. In the current paper a different generalization of CL, called the A measure of stochastic superiority, is proposed, which may be directly applied for any discrete or continuous variable that is at least ordinally scaled. Exact methods for point and interval estimation as well as the significance tests of the A = .5 hypothesis are provided. New generalizations ofCL are provided for the multi-group and correlated samples cases.


Genetics ◽  
2003 ◽  
Vol 165 (2) ◽  
pp. 667-673 ◽  
Author(s):  
W Jason Kennington ◽  
Julia Gockel ◽  
Linda Partridge

AbstractAsymmetrical gene flow is an important, but rarely examined genetic parameter. Here, we develop a new method for detecting departures from symmetrical migration between two populations using microsatellite data that are based on the difference in the proportion of private alleles. Application of this approach to data collected from wild-caught Drosophila melanogaster along a latitudinal body-size cline in eastern Australia revealed that asymmetrical gene flow could be detected, but was uncommon, nonlocalized, and occurred in both directions. We also show that, in contrast to the findings of a previous study, there is good evidence to suggest that the cline experiences significant levels of gene flow between populations.


2020 ◽  
Vol 6 ◽  
pp. 1-4
Author(s):  
Stanislav K Korb

We submitted first results of the DNA studies of the Central Asiatic owlet moths of the genus Euchalcia. Standard cytochrome C oxidase subunit I (COI) gene fragments were sequenced for DNA barcoding of six specimens belonging to Euchalcia herrichi and Euchalcia gyulai. We compared the received sequences between discussed species and with two European Euchalcia species (E. variabilis and E. consona). We found no variability within the COI sequences of the samples collected in the same locality (Alai Mts., Kyrgyzstan), whereas the difference in COI sequences between two populations (Ketmen Mts., Kazakhstan and Alai Mts., Kyrgyzstan) was 0.005.


1971 ◽  
Vol 29 (3) ◽  
pp. 975-982
Author(s):  
Anne Marie Bercik ◽  
John H. Mueller

Schizophrenic and control Ss were compared on the method of generated responses (MGR) and conventional paired-associates (PA), using lists of stimuli which elicited either primarily one response or several responses. The low-dominance list was more difficult, and schizophrenics were generally slower in learning. The MGR, with Ss producing their own responses, was easier than conventional PA (yoked controls). While the MGR reduced the difference between the low- and high-dominance lists, it did not do so differentially for the two populations. The results were discussed in terms of Broen and Storms' theory of “collapsed” response hierarchies in schizophrenia.


1957 ◽  
Vol 02 (3) ◽  
pp. 215-221
Author(s):  
Zbyněk Šidák ◽  
Jiří Vondráček

2021 ◽  
Vol 17 (4) ◽  
pp. 92-96
Author(s):  
E. Tartakovsky

In the present study, we tested the morbidity and salutary hypotheses of immigration investigating satisfaction with life (SWL) among Jewish immigrants from the Former Soviet Union to Israel. The study was conducted using a random representative sample of first-generation immigrants from the Former Soviet Union to Israel (N = 400) and a large geographically dispersed sample of Jews staying in Russia (N = 935). We applied three measures of SWL: general satisfaction with life (GSWL), multifaceted satisfaction with life (MSWL), and relative satisfaction with life (RSWL). The results demonstrated that immigrants were higher than stayers in GSWL. At the same time, the difference between the two populations was not significant in the average scores of MSWL. When comparing the two populations in ten domains of MSWL, immigrants reported higher satisfaction only in medical care. Stayers reported higher satisfaction in four domains: work, family relationships, relationships with friends, and entertainment and leisure. Immigrants assessed their standard of life as higher compared to the premigration period and to that presently existing in their country of origin. However, they assessed their standard of life as lower compared to the non-immigrant Israelis. Thus, immigration was a mixed blessing for the studied group of immigrants, salutary in some aspects and onerous in others.


Genetics ◽  
1982 ◽  
Vol 101 (2) ◽  
pp. 279-300
Author(s):  
Terumi Mukai ◽  
Sadao I Chigusa ◽  
Shin-Ichi Kusakabe

ABSTRACT Developmental homeostasis of relative viability was examined for homozygotes and heterozygotes using second chromosomes from two populations of Drosophila melanogaster. One was a chromosome population in which spontaneous mutations were allowed to accumulate since it was begun with a single near-normal second chromosome. The second was a natural population approximately at equilibrium. For the estimation of relative viability, the Cy method was employed (Wallace 1956), and environmental variance between simultaneously replicated cultures was used as the index of developmental homeostasis. A new method was used in the estimation of sampling variance for relative viability that was employed for the calculation of environmental variance (error variance between simultaneously replicated cultures — sampling variance). The following findings were obtained.: (1) The difference in environmental variance between homozygotes and heterozygotes could not be seen when a chromosome population with variation due to new mutations was tested. (2) When a chromosome group isolated from an approximate equilibrium population was examined, heterozygotes manifested a smaller environmental variance than the homozygotes if their relative viabilities were approximately the same. (3) There was a slight negative correlation between viability and environmental variance, although opposite results were found when the viabilities of individuals were high, especially when overdominance (coupling overdominance, Mukai 1969 a, b) was manifest. On the basis of these findings, it was concluded that developmental homeostasis was a product of natural selection, and its mechanism was discussed.


1986 ◽  
Vol 28 (4) ◽  
pp. 511-519 ◽  
Author(s):  
R. Jampates ◽  
J. Dvořák

Heterogenetic chromosome pairing in wheat is prevented by the Ph1 locus on the q (=L) arm of chromosome 5B. Two durum wheat cv. Cappelli structural mutants with rearranged 5Bq chromosome arms were investigated to determine the location of the Ph1 locus in the metaphase map and the linkage map of the arm. One of the mutants, Cap5Bq−, has a deletion of subregion 5Bq12.3 between C-bands 5Bq12.2 and 5Bq21 and the other one, Cap5Bq+, has the same subregion duplicated. Each mutant and standard cv. Cappelli were crossed with Aegilops kotschyi, Ae. ovata, Ae. cylindrica, Ae. ventricosa, Ae. juvenalis, and "Ae. crassa 6x." Hybrids involving Cap5Bq− had higher levels of chromosome pairing than those involving cv. Cappelli, whereas those involving Cap5Bq+ had lower levels of pairing than those involving cv. Cappelli. Cap5Bq− was crossed with cv. Cappelli and the F1 was hybridized with Ae. kotschyi and Ae. ventricosa. All hybrids with the 5Bq− chromosome had a higher level of chromosome pairing than those with the standard chromosome. Cap5Bq+ was crossed with cv. Cappelli and the F1 was hybridized with Ae. kotschyi. Most hybrids with the 5Bq+ chromosome had a lower level of chromosome pairing than those with the standard chromosome. Because the difference between the means of the two populations was small (0.43 chiasmata per cell) and the distributions overlapped, the strength of the linkage between the duplication and reduced pairing could not be determined; the data, nevertheless, showed that the reduced pairing must be strongly, if not completely, linked to the duplication. It is therefore concluded that the Ph1 locus is in the euchromatic subregion 5Bq12.3, 5Bq− is a null for Ph1, and 5Bq+ has two Ph1 loci. The 5Bq+ chromosome was substituted into Triticum aestivum cv. Chinese Spring, the substitution was crossed with cv. Chinese Spring ditelosomic 5Bq, and the F1 was crossed with cv. Chinese Spring monosomic 5B. Recombination of C-bands relative to each other and the centromere was determined with the objective of determining the distribution of crossing-over along the 5Bq arm and the linkage of the subregion 5Bq12.3 with the centromere. The distibution of crossing-over was greatly distorted, most occurred in the distal region of the arm. The subregion 5Bq12.3 showed a tight linkage with the centromere, even though it is in the middle of the 5Bq arm. It is proposed to designate the cv. Cappelli Ph1− mutation as ph1c.Key words: Triticum, map distortion, homoeologous pairing, chromosome pairing, chromosome rearrangement.


2020 ◽  
Vol 497 (4) ◽  
pp. 4459-4471 ◽  
Author(s):  
Azadeh Fattahi ◽  
Alis J Deason ◽  
Carlos S Frenk ◽  
Christine M Simpson ◽  
Facundo A Gómez ◽  
...  

ABSTRACT We use magnetohydrodynamical simulations of Milky Way-mass haloes from the Auriga project to investigate the properties of surviving and destroyed dwarf galaxies that are accreted by these haloes over cosmic time. We show that the combined luminosity function of surviving and destroyed dwarfs at infall is similar in the various Auriga haloes, and is dominated by the destroyed dwarfs. There is, however, a strong dependence on infall time: destroyed dwarfs typically have early infall times of less than 6 Gyr (since the big bang), whereas the majority of dwarfs accreted after 10 Gyr have survived to the present day. Because of their late infall, the surviving satellites have higher metallicities at infall than their destroyed counterparts of similar mass at infall; the difference is even more pronounced for the present-day metallicities of satellites, many of which continue to form stars after infall, in particular for $M_{\rm star}\gt 10^7 \, {\rm M}_\odot$. In agreement with previous work, we find that a small number of relatively massive destroyed dwarf galaxies dominate the mass of stellar haloes. However, there is a significant radial dependence: while 90 per cent of the mass in the inner regions (${\lt}20\,$ kpc) is contributed, on average, by only three massive progenitors, the outer regions (${\gt}100\,$ kpc) typically have ∼8 main progenitors of relatively lower mass. Finally, we show that a few massive progenitors dominate the metallicity distribution of accreted stars, even at the metal-poor end. Contrary to common assumptions in the literature, stars from dwarf galaxies of mass $M_{\rm star}\lt 10^7 \, {\rm M}_\odot$ make up less than 10 per cent of the accreted, metal poor stars ([Fe/H] ${\lt}-3$) in the inner $50\,$ kpc.


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