Joke Verheij | PubMed Health

PubMed2004

Localizing a putative mutation as the major contributor to the development of sporadic Hirschsprung disease to the RET genomic sequence between the promoter region and exon 2.

Hirschsprung disease (HSCR), a congenital disorder characterized by intestinal obstruction due to absence of enteric ganglia along variable lengths of the intestinal tract, occurs both in familial and sporadic cases. RET mutations have been found in approximately 50% of the families, but explains only a minority of sporadic cases. This study aims at investigating a possible role of RET in sporadic HSCR patients. Haplotypes of 13 DNA markers, within and flanking RET, have been determined for 117 sporadic HSCR patients and their parents. Strong association was observed for six markers in the 5' region of RET. The largest distortions in allele transmission were found at the same markers. One single haplotype composed of these six markers was present in 55.6% of patients versus 16.2% of controls. Odds ratios (ORs) revealed a highly increased risk of homozygotes for this haplotype to develop HSCR (OR>20). These results allowed us to conclude that RET plays a crucial role in HSCR even when no RET mutations are found. An unknown functional disease variant(s) with a dosage-dependent effect in HSCR is likely located between the promoter region and exon 2 of RET.

Adult↗

PubMed2003

Learning styles: self-reports versus thinking-aloud measures.

BACKGROUND: Learning styles are often assessed through students' self-reports on instruments such as Vermunt's Inventory of Learning Styles (ILS). Recent research, however, has questioned the adequacy of questionnaires for the assessment of learning styles. AIMS: The objective of this paper is to evaluate methods of learning style assessment as a means for identifying students at risk. Therefore, the ILS as a self-report instrument will be compared with the students' actual study processes, assessed through the thinking-aloud method. SAMPLE: In the first study 1,060 students from the Technical University of Delft participated. Thirty-three of them were selected on the ILS for participation in the second study. METHOD: The ILS was administered to the 1,060 participants and their study results (GPA and credit points) were collected. Next, the selected 33 participants studied a technical text while thinking aloud. Knowledge acquisition was measured by means of a post-test. Thinking-aloud protocols were analysed on frequencies of study activities, thus representing process measures of learning styles. RESULTS: The ILS proved to be a rather weak predictor of study results in Study 1. Results from Study 2 show hardly any correspondence between ILS and study process measures, although principal component structures of both measures were highly similar. Furthermore, study process measures outweighed the ILS in the prediction of study results (post-test, GPA and credit points). CONCLUSIONS: Learning style theory was confirmed by results on the study process measures. The assessment of learning styles through self-report instruments such as the ILS, however, should be reconsidered.

Adult↗