A Weighted Nonparametric Procedure for the Combination of Independent Events

A weighted inverse normal procedure for combining independent events is considered. The procedure is utilized to combine results from six clinical studies on homovanillic acid concentrations in relation to the hypothesis that schizophrenia is the result of dopaminergic hyperactivity.     

Nonparametric Evaluation of Repeated Measurement Designs by Point-Symmetry Testing

It is suggested to use simultaneous point-symmetry tests in evaluating trivariate repeated measurement designs nonparametrically. With k =3 treatments being applied to each of N individuals in randomized sequence, pairs of treatments are compared as to 3 variables or incremental sign patterns. It is shown that unifold trivariate tests preserve more information than do multifold univariate tests. The method is illustrated by an example from psychophysiological research.     

A Note on Optimality of Certain Rank Tests for Ordered Alternatives in Randomized Blocks

Nonparametric tests for ordered alternatives in randomised block designs based on within block rankings have been proposed by many authors. This note is concerned with the optimality of the choice of so-called regression constants usually considered in such rank tests. Some examples are discussed.     

Testing goodness of fit for stochastic models of carcinogenesis.

This paper considers the utility of statistical goodness of fit testing in the context of mechanistic models of carcinogenesis. Two stochastic models of carcinogenesis were tested with several sets of experimental and epidemiological data using a formal goodness of fit test specially designed to accommodate censored observations: these were the two-stage model allowing for clonal expansion of initiated cells and its simpler version with gamma distributed promotion time. The results of this application, supplemented by visual examination of local likelihood kernel estimates of the hazard function and the corresponding model-based estimates, show that mechanistic models of carcinogenesis provide a good fit to the data in the majority of cases under study.     

Nonparametric Tests for Slope in Linear Regression Problems

In this paper some new, exactly distribution-free tests are offered for the hypothesis about the slope parameter in one-sample, two-sample, and several-sample simple linear regression problems. Asymptotic relative efficiencies of these test procedures are also studied.     

Effect of temperature on in vitro interactions between Verticillium chlamydosporium and other Meloidogyne-associated micro-organisms

In vitro interaction between Verticillium chlamydosporium (Goddard) andbacteria or fungi was studied at 20 °Cand 15 °C. The frequency of antagonismwas lower at 15 °C for the bacteria, butnot for the fungi. Interaction was affected bytemperature for 33% of the bacteria and 47%of the fungi.     

Observations on variations in electrical conductivity of pure demineralized water: modification (”activation”) of conductivity by low-frequency, low-level alternativing electric fields

 Piccardi and Capel-Boute have previously indicated a number of physical parameters which describe the physico-chemical evolution of pure water over time. Electrical conductivity is such a parameter. Experiments have been carried out in order to investigate correlations between the conductivity of pure water and various parameters. Based earlier work by Halla and Novotny we used an electrical voltage (5 V) of weak frequency (3.4 KHz) to ”activate” water. Results have been positive, the stimulus producing an increase of 10% in electrical conductivity. A biomass test with this water confirmed the observations of Violet that such water produced an increase in vegetation. Measurements of the electrical conductivity of pure water over time showed that ”external phenomena” acted upon control water but did not act upon ”activated” water. In a third series of experiments, water from the same source was put in two bottles: the first was a screened one and the second was a normal one. In this experiment, the influence of variations in electrical atmospheric fields on variations in the electrical conductivity of pure water was confirmed. Received: 11 August 1997 / Accepted: 26 September 1997