Cognitive functions mediate the effect of preterm birth on mathematics skills in young children.

Children born preterm are at risk for cognitive deficits and lower academic achievement. Notably, mathematics achievement is generally most affected. Here, we investigated the cognitive functions mediating early mathematics skills and how these are impacted by preterm birth. Healthy children born preterm (gestational age at birth < 33 weeks; n = 51) and children born full term (n = 27) were tested at ages 5, 6, and 7 years with a comprehensive battery of tests. We categorized items of the TEMA-3: Test for Early Mathematics Abilities Third Edition into number skills and arithmetic skills. Using multiple mediation models, we assessed how the effect of preterm birth on mathematics skills is mediated by spatial working memory, inhibitory control, visual-motor integration, and phonological processing. Both number and arithmetic skills showed group differences, but with different developmental trajectories. The initial performance gap observed in the preterm children decreased over time for number skills but increased for arithmetic skills. Phonological processing, visual-motor integration, and inhibitory control were poorer in children born preterm. These cognitive functions, particularly phonological processing, had a mediating effect on both types of mathematics skills. These findings help define and chart the trajectory of the specific cognitive skills directly influencing math deficit phenotypes in children born very preterm. This knowledge provides guidance for targeted evaluation and treatment implementation.

α-Irradiation setup for primary human cell cultures.

Purpose: We present an α-irradiation setup for the irradiation of primary human cell cultures under controlled conditions using 241Am α-particles.Materials and Methods: To irradiate samples with α-particles in a valid manner, a reliable dosimetry is a great challenge because of the short α-range and the complex energy spectrum. Therefore, the distance between α-source and sample must be minimal. In the present setup, this is achieved by cells growing on a 2 µm thick biaxially-oriented polyethylene terephthalate (boPET) foil which is only 2.7 mm apart from the source. A precise and reproducible exposure time is realized through a mechanical shutter. The fluence, energy spectra and the corresponding linear energy transfer are determined by the source geometry and the material traversed. They were measured and calculated, yielding a dose rate of 8.2 ± 2.4 Gy/min. To improve cell growth on boPET foils, they were treated with air plasma. This treatment increased the polarity and thus the ability of cells attaching to the surface of the foil. Several tests including cell growth, staining for a marker of DNA double-strand breaks and a colony-forming assay were performed and confirm our dosimetry.Conclusion: With our setup, it is possible to irradiate cell cultures under defined conditions with α-particles. The plasma-treated foil is suitable for primary human cell cultures as shown in cell experiments, confirming also the expected number of particle traversals.