784. SALVIA × WESTERAE

Salvia × westerae is described and illustrated, its floral characteristics being contrasted with those of its parents. The characteristics and distribution of the parent species, Salvia haenkei and S. orbignaei, are discussed and short biographies of their eponymous discoverers, Haenke and D'Orbigny are provided. Pollination syndromes in American Salvia are briefly discussed and the rare occurrence of natural hybrids in the Americas is noted.     

Test Statistics for Three-Factor Interaction in 2 × 2 × 2 Contingency Tables

A Monte Carlo simulation was conducted in order to determine the size and power of two proposed tests (the covariance and correlation tests) for three-factor interaction in 2 × 2 × 2 contingency tables. Results were compared to the log-odds ratio test statistic. Simulation showed the correlation test to be more conservative than the covariance test, but less so than the log-odds ratio test. However, the correlation test was the most powerful among the three tests.     

731. MAHONIA × LINDSAYAE ‘CANTAB’

Mahonia×lindsayae P.F. Yeo ‘Cantab’ is illustrated, and its history is revealed. This continues a series of articles on plants connected with the Botanic Garden of Cambridge University – plants either raised there or distributed from there over the past 100 years or so. As with many of the others, this present plant has a complex history, involving accidental notice of seedlings and inferences about parentage; the original living plants have mostly disappeared, but descendants of some of them are still growing.     

Genetic Determinants of Plasma Triglyceride Levels in (OLETF × BN) × OLETF Backcross Rats

Altered lipid metabolism is closely associated with diabetes in humans, although predisposing genetic factors that affect hyperlipidemia have not yet been clarified. Our previously established OLETF strain is an obese rat model of type II diabetes, exhibiting hypertriglycemia as well as hyperinsulinemia, hyperglycemia, insulin resistance, and abundant abdominal fat. To identify genetic factors responsible for dyslipidemic phenotypes in OLETF rats, we performed a whole-genome scan using 293 male (OLETF × BN) × OLETF backcross rats. Our analysis identified two significant quantitative trait loci (QTLs), on rat chromosomes 1 and 8, that are related to fasting triglyceride levels. The chromosome 1 QTL colocalized with Dmo1 (diabetes mellitus, OLETF type 1), a locus previously shown to associate strongly with both fat levels and body weight. The other significant QTL localizes to the chromosome 8 marker D8Mit2, in a region where several apo-lipoprotein genes are clustered.     

The Power Function of the Test for ‘No Three Factor Interaction’ in 2×2×2 Contingency Tables

Three approximations to the power function of the chi-square test for the hypotheses of ‘no three factor interaction’ in a 2 × 2 × 2 contingency table are introduced and compared. The first method is based on the sampling distribution of the logarithm of the odds ratio, the second-on the non-central X² distribution and the third—on the conditional distribution of a cell entry. The last method is found to provide the closest approximation under various alternative hypotheses and sample sizes.     

Songs of hybrid gibbons (Hylobates lar × H. muelleri)

Two hybrid offspring, one male and one female, were produced by a Hylobates muelleri female mated to a Hylobates lar male at Micke Grove Zoo, Lodi, California. Songs of the hybrids were studied at adulthood and compared to the parental-type songs. The hybrid female song is uniquely different from either parental type. The hybrid male song resembles the male song of H. lar, but contains an element that may be unique to H. muelleri. The study demonstrates the utility of sound-spectographic analysis of hybrid vocalizations to further understanding of primate behavioral inheritance.     

Ultrastructural changes in differentiating neuroblastoma × glioma hybrid cells

The ultrastructure of differentiating neuroblastoma × glioma hybrid cells NG108-15 was observed. Cells cultured in growth medium showed undifferentiated features, while cells treated with dBcAMP became round and large, and extended thick long neurites. After 1 week in culture, cells showed features similar to those of normal neurons. The dense cored vesicles with diameters ranging from 60 to 170 nm were observed in differentiated NG108-15 cells, but clear vesicles were usually rare. However, in the case of co-culture with striated myotubes, clusters of clear vesicles appeared in the neurites and terminals. The timecourse of the differentiation process was correlated with results obtained by the electrophysiology and freeze-fracture.     

A Modified Exact Test for 2 × 2 Contingency Tables

A modified exact test is proposed for 2×2 contingency tables. This test, which is based on a less conservative definition of the concept of significance (STONE, 1969) is compared with a modified form of Pearson's X² test and with Tocher's randomized exact (UMPU) test. The sizes of the new test lie near the nominal 0.05 levels while those of the X² test usually exceed the nominal level, sometimes by a factor of 2 or more. The power of the modified test is usually close to that of the UMPU test.     

Beiträge zur Kenntnis der Gattung Digitalis L. (Scrophulariaceae) III. Digitalis × pelia Zerbst & Bocquet,hybr. nov. (Digitalis graeca Ivanina × D. grandiflora Miller), ein natürlicher Hybrid in Griechenland

Un nouvel hybride de digitale est décrit, d'Anilion, dans la chaîne du Pilion (Pélion), dans le nord de la Grèce: le Digitalis × pelia. Les parents sont les D. graeca Ivanina et D. grandiflora Miller. C'est la première mention de cet hybride, encore qu'il ne semble pas rare dans les régions où les deux espèces parentes voisinent. On trouve dans la chaîne du Pilion au sens large une autre espèce de digitale: le D. lanata₂); cette espèce ne peut entrer en ligne de compte comme parent de notre hybride. L'hybridation a probablement été déclanchée par des modifications de l'environnement.     

Approximating Exact Probabilities by χ2 and Continuity-Corrected χ2 in 2×2 Tables

Computations have been performed to find an adequate definition of exact two-sided probabilities in 2times2 contingency tables. It turns out, that both uncorrected χ² and Yates' correction for continuity give only unsatisfactory approximations to the exact probabilities of the hypergeometric distribution. The latter are therefore recommended for general use.     

Note on Simply Calculating Chi-square for a r × c-Contingency Table

For evaluating r × c-contingency tables by χ², a row components formula is proposed which allows calculating χ² less tediously than with the general χ²-formula.     

A Note on the Analysis of a p × 22 Design

TYAGI has given a method of constructing a balanced factorial experiment of the p × 2² type. A complete analysis of such a design with and without recovery of interblock information, using the eigenyalues and eigenvectors of the C-matrix of the design, is given in this paper. KHATRY & SHAH'S method of producing uniformly better estimators is employed to combine the inter and intra block estimates.     

Exact Test of Uniform Association in a 2 × 3 Table

In a similar approach to Fisher's exact test of independence (null association) for a 2 × 2 table, this note gives an exact test of uniform association for a 2 × 3 table.     

Genetic Dissection of “OLETF,” a Rat Model for Non-Insulin-Dependent Diabetes Mellitus: Quantitative Trait Locus Analysis of (OLETF × BN) × OLETF

To identify genetic determinants relevant to non-insulin-dependent diabetes mellitus (NIDDM), we performed a genome-wide analysis for quantitative trait loci (QTLs) using 359 backcross progeny of the Otsuka Long-Evans Tokushima Fatty (OLETF) rat. The OLETF strain is a well-studied animal model of obese NIDDM, with features of hyperinsulinemia, hyperglycemia, insulin resistance, and abundant abdominal fat. Our extensive genomic scanning with 218 markers revealed nine significant QTLs, including a strong determinant of obesity on chromosome 1 (Dmo1: LOD = 13.99, for body weight). Two highly significant QTLs for glucose homeostasis were found, one on chromosome 1 (Dmo4 LOD = 7.16, for postprandial glucose level) and the other on chromosome X (Dmo11/Odb1: LOD = 7.81, for postprandial glucose level). These data are comparable to results of our previous studies of the OLETF rat.