Mean Similarity Coefficient Research Articles

Evaluation of the thermal decomposition apparatus used for toxicity testing of hydraulic fluids

This study examines the applicability of a thermal decomposition apparatus, originally designed for conducting animal toxicity tests, for micro analysis of decomposition products by gas chromatography. The thermal decomposition apparatus, described in the Sixth Report of the Safety and Health Commission for the Mining and Other Extractive Industries has been adapted in order to allow micro sampling of pyrolysis products and to evaluate some critical analytical parameters. On condition that some adjustments are made to the original design, the apparatus makes it possible to produce pyrograms with a mean similarity coefficient of 0.89.

La minimumaj areoj de sursela likenkunajo (Physconia grisea -kunajo)

The qualitative and quantitative minimal areas of a corticolous lichen cormtunity with dominant small foliose thalli (community with Physconia grisea are determinated by means of the Gounot and Calleja method (study of the variation of a mean similarity coefficient in relation to area). These areas are very close and estimated at 150-200 cm2 .

Comparative study of factor structure of Raven's Coloured Progressive Matrices.

The Raven Coloured Progressive Matrices were administered on group or individual bases to children ranging in age from 4 yr. 9 mo. to 11 yr. 0 mo. (N = 728). Factor analysis yielded three factors: 1. Perceptual closure involving complex figures and patterns with heterogeneous inner structures, 2. Concrete and abstract reasoning, 3. Completion of homogeneous patterns and recognition of given elements. Factor matrix comparisons across age groups resulted in a mean similarity coefficient of .75. Comparisons of data with earlier analyses also resulted in high similarity. This supports the hypothesis of a three-factor structure rather than a four-factor solution or a simple dual classification into items which can be solved by perceptual processes and those which require conceptual solutions.

Genetic basis of the crown-size profile pattern.

Although genetic control of crown diameters has been documented by a number of workers (R. H. OSBORNE ET AL, Amer J Hum Genet 10: 350-356, 1958; S. M. GARN ET AL, J Dent Res 44:228-242, 1965; D. W. LEWIS and R. M. GRAINGER, Arch Oral Biol 12:539-544, 1967; and D. H. GOOSE, J Dent Res 46:959-962, 1967), genetic involvement in crown-size patterning has not been ascertained for the whole dentition. To investigate the genetic and chromosomal basis of crown-size profile patterning, crownsize patterns of 960 pairs of subjects from southwestern Ohio were compared. After converting individual measurements into normalized T scores (W. A. MCCALL, Measurement, 1939, pp 505-508) by using a computer program (C. R. BLACK, Ann NY Acad Sci 134: 538-540, 1966), dentitions of each pair of subjects were compared by the product moment correlation, r. The resulting correlation coefficients (rT), involving T-scored values of corresponding teeth, provided a simple expression of the degree of patterned similarity between any two individuals. The use of normalized T scores automatically corrected for sex made possible cross-sexed as well as like-sexed comparisons. Sibling correlations for tooth-size similarity approximated 0.22 for 246 like-sexed and crosssexed brothers and sisters (Table). Parent-child similarities in crown-size profile pattern approximated 0.20 as shown by 90 parent-child pairings. Similarly investigated, 58 pairs of cousins yielded a mean similarity coefficient value of 0.15. Finally, randomly paired, unrelated subjects had a pattern profile similarity value of 0.01, close to the theoretical 0.00 value. With profile-pattern similarity values ranging from 0.90 for monozygotic female twins through 0.20 for parents versus their children, 0.15 for cousins, and 0.00 for unrelated pairs, it is clear that crown-size profile patterns have a genetic basis. The values in the table also show evidence for X-chromosomal involvement in the pattern of the total dentition. Sister-sister values of rT exceeded the remaining sibling correlations.