PubMed · 9617417
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
M L Greenfield, J E Kuhn, E M Wojtys. A statistics primer. Validity and reliability.. https://doi.org/10.1177/03635465980260032401
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The phenotypic variance (V(P)) may be divided into the genetic variance (V(G)), the general environmental variance (V(Eg)), and the special environmental variance (V(Es)). The latter is estimated through repeatability calculation (b). This value is considered the upper limit of heritability and represents maximum genetic variance proportion (V(Gm) = V(G) + V(Eg)) in relation to V(P) (b = (V(G) + V(Eg))/V(P)). This process allows an improved determination of biological relationships among groups from estimators maximizing the genetic information of quantitative characters. Two hundred and thirty-seven individuals inhabiting the northern coast of Chile for 4,000 years were taken as a sample. Measurement was made of six metric characters at both sides of the cranium. Special environmental values (es) were obtained by regression. The difference between these values and the phenotypic values (p) consists in the genetic values plus the general environmental values (g + eg). A mean b value of 0.83 indicated that V(Es) represents 17% of V(P). The results showed: 1) high stability of the maximum genetic variance in time and space, 2) high correlation between the biological relationships model, the phenotypic model, and the maximum genetic model, and 3) random distribution of the nongenetic variation, as expected from the quantitative genetics theory. These results support the use of phenotypic data for the interpretation of the evolution history of prehistoric populations.
The present study proposes a simple and reproducible method to classify the morphology of the suprascapular notch (SSN), on the basis of specific geometrical parameters that clearly distinguish one type from another. Four hundred twenty-three dried scapulas from the Department of Anatomy in the University of Cologne, Germany, were examined. Five types of SSN were observed: type I, without a discrete notch, 35 (8.3%); type II, a notch that was longest in its transverse diameter, 177 (41.85%); type III, a notch that was longest in its vertical diameter, 177 (41.85%); type IV, a bony foramen, 31 (7.3%); type V, a notch and a bony foramen, 3 (0.7%). For the vertical diameter, we took the maximal diameter of the notch perpendicular to the imaginary line that joins the two superior corners of the notch. For the transverse diameter, we took the diameter perpendicular to the midpoint of the vertical diameter. This classification based on the vertical and the transverse diameters of the SSN suggested a clear distinction of the notch types. This simple classification included all the anatomical variations of the SSN. Using this method, the clinician will be able to define easily and quickly the notch type on a plain radiograph, and perhaps be able to correlate suprascapular nerve entrapment with a specific type of SSN.
Explore the source record for details and available documents.