31 research outputs found

    Periconception maternal folate status and human embryonic cerebellum growth trajectories: The Rotterdam predict study

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    We aimed to investigate whether periconceptional maternal folate status affects human embryonic cerebellar size and growth trajectories. In a prospective periconceptional cohort participants filled out questionnaires and received weekly transvaginal 3D-ultrasounds between 7+0 and 12+6 weeks gestational age (GA). Viable non-malformed singleton pregnancies were selected for cerebellar measurements; transcerebellar diameter, (TCD), left and right cerebellar diameters (LCD, RCD). Linear mixed models were performed to estimate associations between questionnaire data on the timing of maternal folic acid supplement initiation and longitudinal cerebellar measurements as a function of crown-rump length (CRL) and GA. Maternal red blood cell folate concentrations were analysed before 8 weeks GA to validate the associations. A total of 263 serial high quality three-dimensional ultrasound scans of 135 pregnancies were studied. Preconceptional compared to postconceptional initiation of folic acid use was associated with slightly larger cerebellar diameters per millimetre increase of CRL (TCD: β = 0.260mm, 95%CI = 0.023-0.491, p<0.05; LCD: β = 0.171mm, 95%CI = 0.038-0.305, p<0.05; RCD: β = 0.156mm, 95%CI = 0.032-0.280, p<0.05) and with proportional cerebellar growth (TCD/CRL:β = 0.015mm/mm, 95%CI = 0.005-0.024, p<0.01; LCD/CRL:β = 0.012mm/mm, 95%CI = 0.005-0.018, p<0.01; RCD/ CRL:β = 0.011mm/mm, 95%CI = 0.005-0.017, p

    The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape : A Large-Scale Genome-Wide Interaction Study

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    Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age-and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to similar to 2.8M SNPs with BMI and WHRadjBMI in four strata (men 50y, women 50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR= 50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may providefurther insights into the biology that underlies weight change with age or the sexually dimorphism of body shape.Peer reviewe

    Cervicale externe wortelresorptie

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    Cervicale externe wortelresorptie

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    Succes van directe pulpaoverkappingen na excaveren

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    Supporting creative problem solving in primary geometry education

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    This intervention study aimed to identify how creative thinking can be supported in geometry education. Fifth-graders received five geometry lessons that incorporated divergent and convergent thinking. Children were assigned to a condition with either no creative thinking support (n = 60), support for divergent thinking (partial support; n = 55) or support for divergent and convergent thinking (full support; n = 59). Divergent thinking was assessed by a multiple-solution task and scored in terms of fluency, flexibility and originality. Convergent thinking was assessed by an idea evaluation task. Repeated measures MANOVA showed that different aspects of divergent thinking (i.e., fluency, flexibility and originality) benefited from different types of support. Students’ fluency scores improved in the full support condition, but decreased in the other two conditions. A reverse pattern was found for flexibility and originality, which decreased in the full support condition but increased in the other conditions. No time and condition effects were found for convergent thinking. In all conditions, there was a non-significant increase in geometry scores. However, geometry performance differed between conditions, and was lower (across pretest and posttest) in the full support condition than in the no support and partial support conditions. These results provide some initial evidence that divergent thinking can be promoted in geometry education. Convergent thinking, on the other hand, might be more difficult to support effectively. As different types of support seem to affect different aspects of divergent thinking, teachers might consider adapting support to the specific task or individual needs of children
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