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Contemporary evidence on the effectiveness of concrete and abstract representations in science education is based solely on studies conducted in college context. There it has been found that learning with abstract representations produces predominantly better outcomes than learning with concrete representations and combining the representations can be even more productive. In the present study, 52 elementary school students used a computer simulation to discover the basic principles of electric circuits. The perceptual concreteness of simulation elements either remained concrete "or" switched from concrete to abstract during the learning. In order to compare the relative effectiveness of the learning conditions and assess the changes in students' conceptual understanding, the students completed a subject knowledge assessment questionnaire before and after learning with the simulation. According to the results, the students gained a better understanding of the circuits by learning with constantly concrete simulation elements than switching from concrete to abstract elements during the learning. Constantly concrete elements also enhanced the learning process by reducing the learning times. The outcomes of the study suggest that the effects of concrete and abstract representations in science education are notably different in elementary school context as compared with college contexts.

We examined the perceptual discrepancy profiles between self- and peers, and self- and teacher evaluations of adolescents' social competence (SC) and the interrelations of these profiles with self-reported depressive symptoms. The participants were 390 Finnish lower secondary school pupils. Latent profile analysis revealed five classes of discrepancy profiles; adolescents with congruent perceptions, quite congruent perceptions, and positively discrepant perceptions of SC reported lower scores of depressive symptoms, whereas those with negatively and extremely positively discrepant perceptions of SC reported the highest scores of depressive symptoms. The larger the discrepancy between self- and others' evaluations of SC were, the more depressive symptoms were reported. The results indicate that interventions designed to mitigate depression need to be tailored to individual needs., (© 2019 Society for Research on Adolescence.)

Three new alkyl glycosides with similar molecular structures (oleyl and oleoyl alkyl chains and various head groups: disaccharide, trisaccharide and disaccharide with an additional amidoethoxy spacer) were synthesized and their supramolecular structure in aqueous solution was investigated. Small angle neutron scattering, surface tension measurement and the contact preparation method were applied to get molecular structure-property relationships. Although the chemical structures differ only in small details, their CMC values, lyotropic phase behaviour, surface area per surfactant molecule in the micelle and at the liquid-air interface, and the size and shape of the micelles are very different. We have found three different types of aggregates: spherical, cylindrical and polymer-like micelles in dilute solutions.