Die Beurteilung angehender Lehrer*innen im Referendariat. Relevanz, Kontext und erste Explorationen

Der Autor untersucht eine noch kaum diskutierte Prüfungspraxis, die schriftliche Beurteilung angehender Lehrpersonen im Referendariat. Er stellt Ansatz und explorativ an ersten Daten den methodischen Zugang seiner Grounded Theory Studie zur Prüfungspraxis mit schriftlichen Gutachten von Fach- und Schulleistungen im Referendariat dar. Dabei arbeitet er unter anderem am Beispiel der Klassenführung heraus, dass zum einen – unter Bezugnahme auf den Kompetenzbegriff – eine grundsätzliche Erlernbarkeit der wichtigsten Berufskompetenzen postuliert werde, dass aber im Gegensatz dazu in starkem Ausmaß Persönlichkeitsaspekte als Erklärung von Berufserfolg in den Gutachten herangezogen würden, deren Erlernbarkeit – zumindest in der kurzen Zeit – fraglich ist. (DIPF/Orig.

Mitochondrial sequence data expose the putative cosmopolitan polychaete Scoloplos armiger (Annelida, Orbiniidae) as a species complex

Background Polychaetes assigned as Scoloplos armiger (Orbiniidae) show a cosmopolitan distribution and have been encountered in all zoogeographic regions. Sibling S. armiger-like species have been revealed by recent studies using RAPDs and AFLP genetic data. We sequenced a ~12 kb fragment of the Scoloplos cf. armiger mitochondrial genome and developed primers for variable regions including the 3' end of the cox3 gene, trnQ, and most of nad6. A phylogenetic analysis of this 528-nucleotide fragment was carried out for S. armiger-like individuals from the Eastern North Atlantic as well as Pacific regions. The aim of this study is to test the cosmopolitan status, as well as to clarify the systematics of this species complex in the Eastern North Atlantic, while using a few specimens from the Pacific Ocean for comparision. Results Phylogenetic analysis of the cox3-trnQ-nad6 data set recovered five different clades of Scoloplos cf. armiger. The fragment of the mitochondrial genome of Scoloplos cf. armiger is 12,042 bp long and contains 13 protein coding genes, 15 of the 22 expected tRNAs, and the large ribosomal subunit (rrnl). Conclusion The sequenced cox3-trnQ-nad6 fragment proved to be very useful in phylogenetic analyses of Scoloplos cf. armiger. Due to its larger sampling scale this study goes beyond previous analyses which used RAPD and AFLP markers. The results of this study clearly supports that Scoloplos armiger represents a species complex and not a cosmopolitan species. We find at least two S. armiger-like species within the Pacific region and three different S. armiger-like species in the North Atlantic. Implications for the taxonomy and the impact on ecological studies are discussed

“Digital In, Digital Out?“ – Evidence for a Curvilinear Relationship Between IT Experience in Top Management Teams and Firms’ Digital Orientation

To drive digital transformation, firms are increasingly adding IT-experienced executives to their top management team (TMT). Yet, whether IT-experienced executives can aid firms to achieve digital transformation remains unresolved theoretically and empirically. Drawing on human capital and group literature, we propose that there are limits to the benefits received from adding IT-experienced executives to a TMT, resulting in a curvilinear relationship between the share of IT-experienced executives in the TMT and a firm’s digital orientation. We also propose that this relationship is moderated by CEO entrepreneurial orientation and power concentration in the TMT. We test and find support for most of our hypotheses using a secondary panel data set comprising 1,855 firm-year observations from 256 firms listed in the S&P 500 between 2005 and 2017

Goal Size Signaling in Entrepreneurial Finance: Evidence for Costless and Simultaneous Signaling in Initial Coin Offerings

Initial Coin Offerings (ICOs), a novel form of entrepreneurial finance, are characterized by extreme information asymmetry. To reduce this asymmetry and attract potential investors, entrepreneurs send signals about unobservable characteristics of their ventures to investors. This paper examines the signaling effects of entrepreneurs’ fundraising goals in ICOs. Using a hand-collected dataset of more than 400 ICOs, we show that the relationship between the size of fundraising goals and actual funding obtained follows curvilinear shapes. We also find that these curvilinear shapes are contingent on the presence of simultaneously sent, costless signals. Our findings enhance understanding how fundraising goals affect fundraising success and provide evidence that in ICOs costless signals are interpreted by investors in conjunction with each other

Virtual Element Method for Cross-Wedge Rolling during Tailored Forming Processes

In this work we present an application of the virtual element method (VEM) to a forming process of hybrid metallic structures by cross-wedge rolling. The modeling of that process is embedded in a thermomechanical framework undergoing large deformations, as outlined in [1, 2]. Since forming processes include mostly huge displacements within a plastic regime, the difficulty of an accurate numerical treatment arises. As shown in [3], VEM illustrates a stable, robust and quadratic convergence rate under extreme loading conditions in many fields of numerical mechanics. Numerically, the forming process is achieved by assigning time-dependent boundary conditions instead of modeling the contact mechanics yielding to a simplified formulation. Based on the two metallic combinations of steel and aluminum, different material properties are considered in the simulations. The purpose of this contribution is to illustrate the effectiveness of such a non-contact macroscopic framework by employing suitable boundary conditions within a virtual element scheme. A comparison with the classical finite element method (FEM) is performed to demonstrate the efficiency of the chosen approach. The numerical examples proposed in this work stem out from the DFG Collaborative Research Centre (CRC) 1153 “Process chain for the production of hybrid high-performance components through tailored forming”

Den einen Lehrkräftemangel gibt es nicht. Ein Diskussionsbeitrag zur Differenzierung

Die mediale Berichterstattung, die politische Diskussion sowie der wissenschaftliche Diskurs zum (vermeintlich richtigen) Umgang mit dem Lehrkräftemangel in der Bundesrepublik Deutschland werden zunehmend sehr allgemein und somit verkürzt geführt. Wir möchten dazu anregen, in der mitunter pauschalen Diskussion die Perspektiven auf den Lehrkräftemangel zu differenzieren, um den vielfältigen Problemlagen gerecht zu werden. Wir unterscheiden in der folgenden Darstellung zwischen der räumlichen Dimension, der Differenzierung nach Schulformen und Lehrämtern sowie nach Unterrichtsfächern. (DIPF/Orig.

Wissensaustausch zwischen Forschung und Praxis erfolgreich gestalten

Um die gesellschaftliche Transformation zu gestalten, wird der Austausch von Wissen zwischen Wissenschaft und Praxis immer wichtiger. Dieser Artikel benennt Prinzipien, Kompetenzen und Rahmenbedingungen für erfolgreichen Wissensaustausch

A distributed wireless MAC scheme for service differentiation in WLANs.

Mobile communications is evolving due to the recent technological achievements in wireless networking. Today, wireless networks exist in many forms, providing different types of services in a range of local, wide area and global coverage. The most widely used WLAN standard today is IEEE 802.11. However, it still has problems with providing the QoS required for multimedia services using distributed methods. In this thesis, a new distributed MAC scheme is proposed to support QoS in wireless LANs. In the scheme, stations use CSMA for channel access, with collisions between stations being resolved by sending a set of beacons in a predefined manner, and virtual collisions being resolved by schedulers at the stations. The proposed MAC scheme is analyzed mathematically, for two-priority case, and the results obtained are validated by simulation. The mathematical model estimates the average delay experienced by data packets of priority one and two under different conditions. A performance evaluation study of the proposed MAC scheme as well as the IEEE 802.11 DCF, and IEEE 802.11e EDCF MAC schemes is also done by means of stochastic simulation. It is found that the results obtained by simulation are in very good agreement with the analytical results, thereby validating them. Moreover, the simulation study evaluated different performance measures of these MAC schemes. The results showed that the IEEE 802.11 DCF scheme does not support QoS, but the proposed MAC scheme and the upcoming IEEE 802.11 EDCF both do. In general, the results show that the proposed MAC scheme performs equally or better than the current IEEE 802.11 DCF scheme in every case considered. It is also found that the proposed MAC scheme performs equally well as the upcoming IEEE 802.11e EDCF scheme, in every case considered in this thesis