A statistical evaluation of the basis for predicting stature from lengths of long bones in European populations

The differences between the variance structures of the bivariate pairs (height, length of the femur) and (height, length of the tibia) are insignificant when estimated from male and female samples of European derived populations, thus the regression lines for the predictions of height are parallel. The variance of height in samples of predicted heights is discussed and the consequences for the statistical analysis of average heights are indicated.     

Pairwise Comparisons in Each of Several Groups with Heterogenous Group Variances

Pairwise comparison procedures are frequently applied to analyze experimental results. In particular, practitioners in the area of medical researches often encounter situations which require these statistical techniques to compare various treatments. In this article, we focus on pairwise comparison procedures in a two‐factor design, where comparisons of one factor are made simultaneously for each level of another factor. For example, several new drugs to treat a certain cancer are being compared for both male and female patients. Previous research efforts were mainly devoted to models with homogeneous variances. The current paper is to address more common scenario where group variances are heterogeneous.     

Comparison of methods of determining stability and adaptation of sweet potato

Summary Four methods were used to determine stability and adaptation of sweet potato (Ipomoea batatas L. Lam.). Data from 14 sweet potato clones evaluated over 14 environments were used. Regression coefficients provided little information with regard to stability but did provide information on response of individual clones. Stability parameters using three of the four methods were highly correlated. The fourth presented different ranking patterns of stability than the other methods. However, the top five stable clones identified by the four methods were almost the same. Two methods were more effective and convenient in discriminating sweet potato clones based on their stabilities. Clones W151, Resisto, and W192 were more stable for no. 1 root yields. W151 and W192 were also stable for total root yields.Paper no. 10832 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7601, USA. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by North Carolina Agricultural Research Service nor does it imply approcal to the exclusion of other products that may be suitable. This article is from a thesis submitted by the senior author in partial fulfilment of the requirements for 1 Ph.D. degree.Present address: VISCA, Baybay, Leyte, Philippines     

Random and fixed effects in plant genetics

Summary A general model for any type of genetic entry is developed which takes into account both the factorial model of gene effects and the ancestral sources, whether inbred lines or outbred varieties, of the genes.Utilizing the model, various genetic designs of fixed entries are explored for the estimation of genetic effects and the testing of genetic hypotheses. These designs consisted of generation means — parents, crosses, various types of backcrosses, and so on — stemming from one or more pairs of parents, and of hybrid combinations from factorial mating designs. Limitations, from the standpoint of genetic effects that can be estimated and genetic hypotheses that can be tested, are developed in considerable detail.When entries from the factorial mating designs are considered to be random, attention is focused on the estimation of genetic variances, rather than effects, and on the concomitant changes in the tests of genetic hypotheses. While there is considerable improvement over fixed entries in the number of types of genetic variances that can be estimated, and of genetic hypotheses that can be tested, they are still very limited in contrast to what would be most desirable.Paper No. 6018 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, North Carolina. This investigation was supported in part by NIH Research Grant No. GM 11546 from the National Institute of General Medical Sciences.Preliminary: This paper was presented at the 7th International Biometric Conference. Since then it has come to various people's attention and I have been encouraged to give it a wider distribution. Except for editing, the paper is essentially as originally written.     

陆地棉开花成铃性状的遗传研究Ⅲ.不同发育阶段的遗传规律

对4个陆地棉品种(系)双列杂交实验的2年观察资料按包括基因型×环境互作的加性-显性遗传模型进行不同发育阶段开花成铃规律的遗传分析。方差分析表明,开花成铃早期主要受显性效应控制,至中后期加性效应作用逐渐增强,基因型×环境互作效应相对较小。不同发育阶段平均开花成铃数与总铃数的相关分析表明,8月1日前加性相关系数为负数或零值,但存在显著或极显著的显性正相关,8月1日后则相反。不同发育阶段平均开花成铃数的条件遗传分析发现不同时期的基因活动强度不同,7月下旬及8月上中旬最大;检测间隔(t-k)对探讨花铃期基因活动规律有重要作用;选择调查周期时应兼顾实验目的、实验环境条件、入选性状及所处的发育阶段。     

Multivariate Polya and Inverse Polya Distributions of Order k

Multivariate Polya and inverse Polya distributions of order k are derived by means of generalized urn models and by compounding the type II multinomial and multivariate negative binomial distributions of order k of PHILIPPOU , ANTZOULAKOS and TRIPSIANNIS (1990, 1988), respectively, with the Dirichlet distribution. It is noted that the above two distributions include as special cases a multivariate hypergeometric distribution of order k, a negative one, an inverse one, a negative inverse one and a discrete uniform of the same order. The probability generating functions, means, variances and covariances of the new distributions are obtained and five asymptotic results are established relating them to the above-mentioned multinomial and multivariate negative binomial distributions of order k, and to the type II negative binomial and the type I multivariate Poisson distributions of order k of PHILIPPOU (1983), and PHILIPPOU , ANTZOULAKOS and TRIPSIAN-NIS (1988), respectively. Potential applications are also indicated. The present paper extends to the multivariate case the work of PHILIPPOU , TRIPSIANNIS and ANTZOULAKOS (1989) on Polya and inverse Polya distributions of order k..     

Sample Variances for Several MINQ-Estimators in the One-way Classification

A generalization of Ahrens' (1965) formulas for sample variances is done, considering the case of MINQ-Estimators which may be biased. The formulas are generally valid, but are restricted for the sake of simplicity to those of the one-way classification. Some MINQ-Estimators are considered and their sample variances calculated.