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P M Kroonenberg

Publications and source records attributed to P M Kroonenberg.

7 recordsLinked to original sources
PubMed2002

Added value of three-way methods for the analysis of mortality trends illustrated with worldwide female cancer mortality (1968-1985).

Trends in mortality rates are usually presented per tumour site or per country without an overall analysis of the complete data encompassing all three aspects (tumour sites, countries, trends). This paper presents a methodology for such an overall analysis using three-way methods applied to a data set on female mortality rates for 17 tumour sites of 43 countries for the years 1968-1985. Multivariate techniques like biplots and three-mode principal component analysis within an overall three-way analysis-of-variance framework were used. We confirmed the known patterns of comparatively high mortality for women due to cancer of the bladder, intestines, pancreas, rectum, breast, ovary, skin and leukaemia and the relatively low mortality rates for liver cancer in Western and Northern Europe, the USA, Australia and New Zealand. Also, the reverse pattern was observed for Middle and Southern Europe, Hong Kong, Singapore, and in Japan, and in some but not all Latin American countries. The relatively mortality due to cancer was high in the lungs, mouth, larynx and oesophagus in the British Isles, but was much less in other European countries. Mortality due to cancer of the thyroid, uterus, gall bladder and stomach was high in Middle European countries, as was the case in Japan, Chile and Costa Rica. Rates were low for Southern European countries, North America, Australia and New Zealand. Specific deviating patterns in the data were the more rapidly decreasing mortality rates for stomach cancer in Chile and Japan and the more rapidly increasing mortality rates for lung cancer in the USA, Scotland and Denmark. In conclusion, using three-way methods, it was feasible to analyse the cancer mortality data in their entirety. This enabled the simultaneous comparison of trends in relative mortality rates between all countries due to all tumour sites, as well as the identification of specific deviating trends for specific tumour sites in specific countries.

Cross-Cultural Comparison↗
PubMed1997

Dynamics of behaviour in the Strange Situation: a structural equation approach.

In this paper, we present a structural equation approach to modelling infant behaviour in the Strange Situation. A model was developed on a Dutch data set, and was subsequently cross-validated for an American data set containing the original Ainsworth data. Model building is reported in some detail as no previous similar analyses of the Strange Situation exist in the literature. The latent variables in the preferred model are stranger wariness, minimization or deactivation of attachment concerns, and maximization or hyperactivation of attachment concerns. Stranger wariness influences only the subsequent behaviour towards the mother, and behaviour in the second reunion episode is dependent on the same mother behaviour in the first reunion episode, and not on other mother behaviours. Structural equation modelling behaviour in the Strange Situation is shown to provide further insight into the dynamics of the procedure.

Analysis of Variance↗
PubMed1995

Classifying infants in the Strange Situation with three-way mixture method of clustering.

The quality of the attachment relationship between mother and infant is typically determined in the Strange Situation. The assignments of infants to the A (avoidant), B (secure), and C (resistant) attachment classes are largely but not exclusively based on measurements during the reunion episodes. In this paper, the measurements in the reunion episodes are used to derive a clustering of the infants via three-way mixture method of clustering, a technique especially designed for clustering three-way mixture method of clustering, a technique especially designed for clustering three-way data (here: infants, variables and episodes). The results are compared with the A-B-C classification, and the relevance of the outcomes for attachment research are discussed. At the same time, the paper aims to demonstrate the use and usefulness of the three-way clustering procedure for data from the social and behavioural sciences.

Environment↗
PubMed1992

The relative effects of maternal and child problems on the quality of attachment: a meta-analysis of attachment in clinical samples.

In this meta-analysis of 34 clinical studies on attachment the hypothesis is tested that maternal problems such as mental illness lead to more deviating attachment classification distributions than child problems such as deafness. A correspondence analysis on 21 North American studies with normal subjects produced a baseline against which the clinical samples could be evaluated. Separate analyses were carried out on studies containing the traditional A, B, C classifications and on studies that also included the recently discovered D or A/C category. Results show that groups with a primary identification of maternal problems show attachment classification distributions highly divergent from the normal distributions, whereas groups with a primary identification of child problems show distributions that are similar to the distributions of normal samples. The introduction of the D or A/C classifications (about 15% in normal samples) reveals an overrepresentation of D or A/C in the child problem groups, but the resulting distribution still is much closer to the normal distributions compared to the samples with maternal problems. In clinical samples, the mother appears to play a more important role than the child in shaping the quality of the infant-mother attachment relationship.

Child Behavior Disorders↗
PubMedDate not supplied

Consensus molecular alignment based on generalized procrustes analysis.

One of the most serious problems in three-dimensional quantitative structure-activity relationship (3D-QSAR) studies is selection of an alignment rule for molecular super position of the compounds in the data set. In 3D-QSAR analyses of structure-activity data, a reference compound in a defined conformation is chosen, and all structures in the data set are aligned with the reference in a pairwise manner. In subsequent steps, conformation/alignment-dependent descriptors are computed for the compounds and compared to those of the reference. This approach gives much weight to the arbitrarily chosen reference molecule and can introduce a bias in the results. Here an alternative, and more general, approach to molecular alignment is presented that is based on Generalized Procrustes Analysis (GPA). The result is a consensus alignment that uses all molecules in the data set and avoids the bias introduced in the pairwise alignment strategy.

Journal Article↗