Macht das Fachstudium einen Unterschied? Zur Rolle der Lehrerexpertise für Lernerfolg und Motivation in der Grundschule

Die vorliegende Grundschulstudie hat zum Ziel, Effekte der Lehrerexpertise auf die Leistungs- und Persönlichkeitsentwicklung von Kindern zu analysieren. Die Lehrerexpertise wurde über das Fachstudium der Lehrkräfte operationalisiert. An einer Stichprobe von 1.126 Grundschulkindern dritter und vierter Klassen wurden die Lernleistungen, der Lernzuwachs, die Lernfreude und die Selbstkonzepte ermittelt. Die Datenauswertung erfolgte mittels Mehrebenenanalysen. Das Fachstudium der Lehrkraft zeigte keinen positiven Effekt auf den Lernzuwachs in der Rechtschreibleistung und in der Mathematik sowie auf das Niveau der Lesekompetenz. Auch die Motivation der Schulkinder erwies sich als vom Fachstudium der Lehrkraft unabhängig. Die Studie liefert einen Beitrag zur Frage nach den Kontextbedingungen der Leistungs- und Persönlichkeitsentwicklung im Grundschulalter. (DIPF/Orig.)The present elementary-school study aims at analyzing the impact of the teachers\u27 subject-matter expertise on children\u27s achievement and personality development. The teacher expertise was operationalized through the teachers\u27 special subject-related training. On the basis of a random sample survey among 1.126 elementary school kids in third and fourth grade, learning achievement, increase in learning, the pleasure derived from learning, and the children\u27s selfconcepts were determined. The data were evaluated through multi-level analyses. The teachers\u27 special subject-related studies showed no positive impact on achievement growth in spelling and in maths nor did it influence the level of reading competence. Furthermore, the children\u27s motivation to learn proved to be independent of the teachers´ subject-matter training. The study provides a contribution to the issue of context-related conditions of achievement and personality development among elementary-school children. (DIPF/Orig.

Exploiting Gene Families for Phylogenomic Analysis of Myzostomid Transcriptome Data

BACKGROUND: In trying to understand the evolutionary relationships of organisms, the current flood of sequence data offers great opportunities, but also reveals new challenges with regard to data quality, the selection of data for subsequent analysis, and the automation of steps that were once done manually for single-gene analyses. Even though genome or transcriptome data is available for representatives of most bilaterian phyla, some enigmatic taxa still have an uncertain position in the animal tree of life. This is especially true for myzostomids, a group of symbiotic (or parasitic) protostomes that are either placed with annelids or flatworms. METHODOLOGY: Based on similarity criteria, Illumina-based transcriptome sequences of one myzostomid were compared to protein sequences of one additional myzostomid and 29 reference metazoa and clustered into gene families. These families were then used to investigate the phylogenetic position of Myzostomida using different approaches: Alignments of 989 sequence families were concatenated, and the resulting superalignment was analyzed under a Maximum Likelihood criterion. We also used all 1,878 gene trees with at least one myzostomid sequence for a supertree approach: the individual gene trees were computed and then reconciled into a species tree using gene tree parsimony. CONCLUSIONS: Superalignments require strictly orthologous genes, and both the gene selection and the widely varying amount of data available for different taxa in our dataset may cause anomalous placements and low bootstrap support. In contrast, gene tree parsimony is designed to accommodate multilocus gene families and therefore allows a much more comprehensive data set to be analyzed. Results of this supertree approach showed a well-resolved phylogeny, in which myzostomids were part of the annelid radiation, and major bilaterian taxa were found to be monophyletic

Steam Drum Design for Direct Steam Generation

For the direct steam generation in solar fields, the recirculation concept has been demonstrated in several installations. Water masses in the solar field vary during transient phases, such as passing clouds. The volume of the steam drum can serve as a buffer during such transients by taking in excess water and providing water storage. The saturated steam mass flow to the superheating section or the consumer can be maintained almost constant during short transients; therefore the steam drum plays a key role for constant steam supply. Its buffer effect depends on the right sizing of the steam drum for the prevailing situations. Due to missing experiences, steam drums have been sized under conservative assumptions and are thereby usually oversized. With this paper, experiences on the steam drum of the 5 MWel TSE1 power plant are discussed for optimized future plant design. The results are also of relevance for process heat installations, in which saturated steam is produced by the solar field

Experience of operating a solar parabolic trough direct steam generation power plant with superheating

TSE1 is the first solar thermal power plant operating in Southeast Asia. It was planned by Solarlite GmbH with support of Tiede- & Niemann GmbH, both German based. It is the first power plant with direct steam generation (DSG) concept and superheating in parabolic troughs. The solar field has a nominal power of 19 MWth driving a 5 MWel turbine by superheated steam at 30 bar and 330 °C. During 2010/2011 Solarlite built the solar field, while the later owner and operator Thai Solar Energy (TSE) from Bangkok built the power block, in Kanchanaburi, Thailand. TSE1 is being operated by TSE since January 2012 (Krüger et al., 2012). This publication is based on a study within the KanDis project, funded by the German Federal Ministry for Economic Affairs and Energy, in which an extensive database of records of almost 500 sensors installed in the power plant (solar field and power block) has been investigated. The data have been provided by Solarlite with a time resolution of about 1 minute. Within the KanDis project, a stable operation could be demonstrated (Khenissi et al., 2015, Krüger et al., 2016). Even under the fluctuating irradiance conditions in the rainy season of Thailand, the turbine could be operated well and generate electricity. Evaluation of the operation data has helped to learn more about DSG behaviour. The TSE1 layout and the implemented control strategies were evaluated and strategies for improvement of TSE1 are suggested within this paper. From the experiences with the TSE1 power plant, conclusions could be drawn to improve the layout and control of future DSG plants