141 research outputs found
Zur Bedeutung von Unterrichtsqualität für die naturwissenschaftliche Kompetenz von Grundschulkindern. Ein Fokus auf Kinder mit ungünstigen Lernvoraussetzungen
Research on classroom instruction has consistently identified characteristics that contribute to student learning. For instance, these include structural-organizational aspects (e.g., classroom management) and affective aspects (e.g., classroom social climate). The idea that the effects of instruction may differentially depend on students’ characteristics has been investigated within the scope of aptitude-treatment-interactions (ATI) research. This study of elementary school (1,041 students, 54 classes) builds on ATI and examines main effects and interaction effects of instructional quality (i.e., classroom management and classroom social climate) and individual risks of school failure (i.e., demographic risk: immigration background or functional risk: low cognitive ability scores) on students’ science competence. Based on hierarchical linear modeling and class-level aggregated student ratings of instructional quality, results show a positive link between classroom social climate and science competence but not for classroom management and science competence. As its most important finding, our study demonstrates the compensatory capacity of instructional quality to narrow the achievement gap between students at risk and their peers. Furthermore, classroom management also counteracted risk of school failure when controlling for students’ language proficiency. (DIPF/Orig.)Im Rahmen von Forschung zu gutem Unterricht wurden Unterrichtsqualitätsmerkmale identifiziert, die mit dem Lernerfolg von Schülerinnen und Schülern verbunden sind. Diese beinhalten bspw. strukturell-organisatorische Aspekte, wie Classroom Management, oder affektive Aspekte, wie das Klassenklima. Dass der Lernerfolg nicht nur von Unterrichtsmerkmalen, sondern auch von deren Wechselspiel mit den individuellen Lernervoraussetzungen abhängt, ist Thema der Forschung zu Aptitude-Treatment-Interactions (ATI). Gegenwärtig erfährt diese Forschung erneute Aufmerksamkeit und bestätigende empirische Befunde. Diese Studie an deutschen Grundschulen (1041 Kinder aus 54 Klassen) knüpft daran an und prüft Haupt- und Interaktionseffekte von Unterrichtsqualitätsmerkmalen (Classroom Management und Klassenklima) sowie individuellen Lernvoraussetzungen (Migrationshintergrund oder geringe kognitive Grundfähigkeiten) für die naturwissenschaftliche Kompetenz von Grundschulkindern. Ergebnisse aus Mehrebenenanalysen zeigen einen positiven Zusammenhang zwischen Klassenklima und naturwissenschaftlicher Kompetenz, nicht aber zwischen Classroom Management und naturwissenschaftlicher Kompetenz. Darüber hinaus zeigten sich Interaktionseffekte zwischen Unterrichtsqualitäts- und Schülermerkmalen dahingehend, dass Unterrichtsqualität einen ausgleichenden Effekt auf die Leistungen von Kindern mit ungünstigen Lernvoraussetzungen und diejenigen ihrer Mitschülerinnen und Mitschüler ausübte. Dieser kompensatorische Effekt zeigte sich für Classroom Management auch nach Kontrolle sprachlicher Kompetenzen. (DIPF/Orig.
Comparison of the Effects of Early Pregnancy with Human Interferon, Alpha 2 (IFNA2), on Gene Expression in Bovine Endometrium
Interferon tau (IFNT), a type I IFN similar to alpha IFNs (IFNA), is the pregnancy recognition signal produced by the ruminant conceptus. To elucidate specific effects of bovine IFNT and of other conceptus-derived factors, endometrial gene expression changes during early pregnancy were compared to gene expression changes after intrauterine application of human IFNA2. In experiment 1, endometrial tissue samples were obtained on Day (D) 12, D15, and D18 postmating from nonpregnant or pregnant heifers. In experiment 2, heifers were treated from D14 to D16 of the estrous cycle with an intrauterine device releasing IFNA2 or, as controls, placebo lipid extrudates or PBS only. Endometrial biopsies were performed after flushing the uterus. All samples from both experiments were analyzed with an Affymetrix Bovine Genome Array. Experiment 1 revealed differential gene expression between pregnant and nonpregnant endometria on D15 and D18. In experiment 2, IFNA2 treatment resulted in differential gene expression in the bovine endometrium. Comparison of the data sets from both studies identified genes that were differentially expressed in response to IFNA2 but not in response to pregnancy on D15 or D18. In addition, genes were found that were differentially expressed during pregnancy but not after IFNA2 treatment. In experiment 3, spatiotemporal alterations in expression of selected genes were determined in uteri from nonpregnant and early pregnant heifers using in situ hybridization. The overall findings of this study suggest differential effects of bovine IFNT compared to human IFNA2 and that some pregnancy-specific changes in the endometrium are elicited by conceptus-derived factors other than IFNT
Embedded formative assessment and classroom process quality. How do they interact in promoting students\u27 science understanding
In this study we examine the interplay between curriculum-embedded formative assessment-a well-known teaching practice-and general features of classroom process quality (i.e., cognitive activation, supportive climate, classroom management) and their combined effect on elementary school students\u27 understanding of the scientific concepts of floating and sinking. We used data from a cluster-randomized controlled trial and compared curriculum-embedded formative assessment (17 classes) with a control group (11 classes). Curriculum-embedded formative assessment and classroom process quality promoted students\u27 learning. Moreover, classroom process quality and embedded formative assessment interacted in promoting student learning. To ensure effective instruction and consequently satisfactory learning outcomes, teachers need to combine specific teaching practices with high classroom process quality. (DIPF/Orig.
The connection between teaching and learning. Linking teaching quality and metacognitive strategy use in primary school
Background: In order for teaching to be successful, students need to be actively involved in learning. However, research on teaching effectiveness often neglects students\u27 learning activities. Although it is assumed that effective teaching promotes the use of beneficial learning activities, empirical evidence for this connection is still limited. Aims: This study aimed to investigate the connection between effective teaching and reported learning activities. We hypothesize specific relations between a three-dimensional model of teaching quality (i.e., cognitive activation, supportive climate, and classroom management) and students\u27 reported use of metacognitive strategies. Students\u27 intrinsic motivation is considered as a mediator and a moderator of this connection. Sample: N = 1,052 students from 53 German primary school classes and their science teachers participated. Methods: Data were collected through classroom or video observation and questionnaires over a period of approximately 2 months. Multilevel analysis was utilized to test our hypotheses. Results: Each dimension of teaching quality positively predicted students\u27 reported use of metacognitive strategies. For supportive climate, this connection was mediated by students\u27 intrinsic motivation. Cognitive activation negatively predicted the slopes between students\u27 reported metacognitive strategy use and motivation. Conclusions: The results support the notion that effective teaching is connected to learning activities and stress the importance of students\u27 learning motivation. Results from the cross-level interaction could indicate that especially less motivated students\u27 reported metacognitive strategy use might be supported by cognitively activating teaching. (DIPF/Orig.
Komorbidität spezifischer Lernstörungen und psychischer Auffälligkeiten. Ein Literaturüberlick
Es wird eine Übersicht über die Forschung zu Komorbiditäten von spezifischen Lernstörungen (SLS) und psychischen Auffälligkeiten gegeben. Eine Literatursuche erbrachte 1100 Artikel, von denen nach explizierten Kriterien 170 für die weiteren Analysen ausgewählt wurden. Ausgeschlossen wurden u.a. Artikel zu nonverbalen Lernstörungen, Buchrezensionen, Einleitungen zu Sonderheften sowie Fallstudien. Die Ergebnisse der Literaturrecherche zeigen, dass die Forschung sich zum großen Teil auf nicht näher spezifizierte Lernstörungen und Lesestörungen bezieht. In Bezug auf Komorbiditäten sind ADHS und sozial-emotionale Probleme die am häufigsten untersuchten Themen. Kinder mit SLS zeigen eine erhöhte Neigung zu externalisierenden und internalisierenden Auffälligkeiten, die jedoch unterhalb eines klinisch relevanten Niveaus liegt. ADHS scheint die am häufigsten auftretende Komorbidität bei Lese- und Rechtschreibstörung zu sein. Das Verhältnis von SLS zu psychischen Auffälligkeiten wird teilweise durch eine mangelnde Effizienz der Funktion des Arbeitsgedächtnisses und Aufmerksamkeitsstörung mediiert. Weiterer Forschungsbedarf besteht insbesondere zur Frage nach Komorbiditäten bei Rechenstörungen. Metaanalysen für den Bereich des Zusammenhangs von SLS und externalisierende Auffälligkeiten stehen noch aus. (DIPF/Orig.)The aims of this literature review were to give an overview of the current knowledge on the comorbidity between Specific Learning Disabilities (SLD) and psychopathological problems. The search yielded 1100 articles, of which 170 were selected that deal with both SLD and psychopathological problems. We excluded articles about Nonverbal Learning Disability, book reviews, introductions to special issues, and case studies. The results show that most research has been done on general (unspecified) learning disabilities and reading disabilities. ADHD and social-emotional problems are the most studied comorbidities. The rate of both externalising and internalising behaviour problems is increased in children with SLD, but not on a clinical level. ADHD forms the highest comorbidity of all SLD\u27s except math disability. The link between SLD and psychopathological problems seems partly mediated by inefficiencies in working memory functioning and attention. To increase knowledge and ultimately improve the suitability of SLD-interventions, more original research is needed in the fields of math disabilities. Meta-analyses are needed about the relations between SLD and externalising problems. (DIPF/Orig.
Development of working memory from grade 3 to 5. Differences between children with and without mathematical learning difficulties
Based on the finding that children with mathematical learning difficulties (MLD) have deficits in working memory (WM), the question arises as to whether these children differ from typical learners only in the level or also in the developmental trajectories of WM functioning. To this end, the WM of 80 children with MLD and 71 typical learners was assessed longitudinally from third to fifth grade. Typical learners outperformed children with MLD in the phonological, visuospatial and central executive WM functioning in third grade. Latent change analyses indicated that both phonological and central executive WM functioning developed in a parallel pattern in children with MLD and in typical learners. In contrast, visuospatial WM functioning revealed a different development in children with and without MLD since the gap between both groups decreased over time. Overall, despite starting at a lower level, the WM functioning in children with MLD did not develop more slowly. (DIPF/Orig.
Comparison of lycopene, ?-carotene and phenolic contents of tomato using conventional and ecological horticultural practices, and arbuscular mycorrhizal fungi (AMF)
Los frutos de tomate son ricos en compuestos antioxidantes que han sido reconocidos como benéficos para la salud humana y los manejos hortÃcolas pueden influir la concentración de estos metabolitos secundarios. Los hongos formadores de micorrizas arbusculares (HFMA) pueden influir en la absorción de nutrientes y agua por la planta. El estudio, llevado a cabo en invernadero, examinó si tomates 'Vitella F1', cultivados orgánicamente, se diferencian en su contenido de licopeno, ?-caroteno y fenoles totales en los frutos de tomates manejados convencionalmente. Los tratamientos fueron los métodos de cultivo: convencional, orgánico, convencional+HFMA y orgánico+HFMA. Comparando los métodos de cultivo, no se encontró ninguna diferencia significativa para los parámetros nutritivos analizados; solamente tomates manejados orgánicamente tuvieron un contenido de fenoles totales un poco menor. En los dos métodos de cultivo, las plantas inoculadas con HFMA (Glomus sp.) formaron contenidos más altos de licopeno en los frutos que los sin inoculación. Los tomates manejados orgánicamente aumentaron su concentración de ?-caroteno y de los fenoles totales a consecuencia del tratamiento con HFMA. La aplicación de HFMA aumentó el peso fresco del fruto pero no el del tallo. El aumento del crecimiento y la adquisición de los nutrientes en tomate demostraron el potencial de la colonización con HFMA para incrementar la concentración de compuestos antioxidantes en el fruto. La mosca blanca (Trialeurodes vaporariorum) fue controlada exitosamente con la aplicación de la tierra diatomaceous Fossil Shield® 90 en los tratamientos orgánicos y con Applaud® en el cultivo convencional.Tomate-Solanum lycopersicu
Validation of the network of relationship inventory in female and male adolescents
Friendships and their different qualities have been shown to be important for adolescents\u27 socio-emotional development and psychological adjustment. In empirical research on such friendship qualities, the Network of Relationship Inventory-Relationship Quality Version (NRI-RQV) is a widely used questionnaire. Here, we conduct an extensive validation of a German version of the NRI-RQV, investigating its factor structure, reliability, and concurrent validity, in a sample of N= 679 adolescents aged 13-18 years. Applying multigroup confirmatory factor analysis, we further test whether the factor structure of the friendship quality construct holds across groups of males and females. Results showed that a structure with nine correlated first-order factors fit the data well, indicating nine distinct friendship qualities in males and females. Measurement invariance testing suggested the same underlying friendship quality construct, albeit differences in mean scores per gender. As evidence for concurrent validity, closeness and discordant friendship qualities showed expected correlations with empathy and social problems, respectively, but not with aggressive behavior. Overall, results indicate good psychometric properties for the German version of the NRI-RQV as a measure of friendship qualities in both males and females. (DIPF/Orig.
Dissecting the knee - Air shower measurements with KASCADE
Recent results of the KASCADE air shower experiment are presented in order to
shed some light on the astrophysics of cosmic rays in the region of the knee in
the energy spectrum. The results include investigations of high-energy
interactions in the atmosphere, the analysis of the arrival directions of
cosmic rays, the determination of the mean logarithmic mass, and the unfolding
of energy spectra for elemental groups
Development of an artificial synovial fluid useful for studying Staphylococcus epidermidis joint infections
Staphylococcus epidermidis is a major causative agent of prosthetic joint infections (PJI). The ability to form biofilms supports this highly selective pathogenic potential. In vitro studies essentially relying on phenotypic assays and genetic approaches have provided a detailed picture of the molecular events contributing to biofilm assembly. A major limitation in these studies is the use of synthetic growth media, which significantly differs from the environmental conditions S. epidermidis encounters during host invasion. Building on evidence showing that growth in serum substantially affects S. epidermidis gene expression profiles and phenotypes, the major aim of this study was to develop and characterize a growth medium mimicking synovial fluid, thereby facilitating research addressing specific aspects related to PJI. Using fresh human plasma, a protocol was established allowing for the large-scale production of a medium that by biochemical analysis matches key characteristics of synovial fluid and therefore is referred to as artificial synovial fluid (ASF). By analysis of biofilm-positive, polysaccharide intercellular adhesion (PIA)-producing S. epidermidis 1457 and its isogenic, PIA- and biofilm-negative mutant 1457-M10, evidence is provided that the presence of ASF induces cluster formation in S. epidermidis 1457 and mutant 1457-M10. Consistent with the aggregative properties, both strains formed multilayered biofilms when analyzed by confocal laser scanning microscopy. In parallel to the phenotypic findings, expression analysis after growth in ASF found upregulation of genes encoding for intercellular adhesins (icaA, aap, and embp) as well as atlE, encoding for the major cell wall autolysin being responsible for eDNA release. In contrast, growth in ASF was associated with reduced expression of the master regulator agr. Collectively, these results indicate that ASF induces expression profiles that are able to support intercellular adhesion in both PIA-positive and PIA-negative S. epidermidis. Given the observation that ASF overall induced biofilm formation in a collection of S. epidermidis isolates from PJI, the results strongly support the idea of using growth media mimicking host environments. ASF may play an important role in future studies related to the pathogenesis of S. epidermidis PJI
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