Interesse durch Öffnung des Unterrichts - wodurch?

Aus motivationspsychologischer Forschungstradition ist bekannt, dass das Empfinden von Autonomie oder Selbstbestimmung unabdingbar für Aufbau und Erhalt von intrinsischer Motivation und Interesse ist. Für verschiedene Formen der Öffnung von Unterricht konnte auch gezeigt werden, dass sie dazu beitragen, das Interesse von Schüler/innen zu unterstützen. Nicht geklärt ist bislang jedoch, ob dieser Zusammenhang zwischen Öffnung von Unterricht und Interesse tatsächlich über das Empfinden von Selbstbestimmung geschieht oder ob andere Einflussfaktoren hier zum Tragen kommen. Die Daten einer Studie mit 1091 Grundschüler/innen aus 45 Klassen zeigen, dass in den untersuchten Klassen die Kinder mehr Interesse am Unterricht angaben, wenn dieser Unterricht durch Mitbestimmungsmöglichkeiten für sie geprägt war und sie sich dadurch als selbstbestimmt empfanden. Neben diesem Pfad über das Selbstbestimmungsempfinden gibt es jedoch keine weiteren positiven Zusammenhänge zwischen Öffnung von Unterricht und Interesse. Zugleich weisen die Schüler/innen, die sich trotz vorhandener Freiräume im Unterricht als wenig selbstbestimmt empfinden, das geringste Interesse auf. (DIPF/Orig.)Numerous results from research in motivation psychology show that the feeling of autonomy and self-determination is indispensable for constitution and maintenance of intrinsic motivation and interest. In addition it has been shown that different forms of open education contribute to support student\u27s interest. It is ambiguous however whether this correlation between open education and interest is actually linked to the feeling of self-determination or if it is effected by other psychological factors. Our own studies with 1091 students from 45 classes at elementary schools show that children have more interest in instruction contents if this teaching is affected by opportunities of participation which gives them a feeling of self-determination. Beside this path there was no positive correlation between open education and interest, however. At the same time the students showed a minimum interest, who felt less self-determined despite obviously existing open forms of education. (DIPF/Orig.

Cooperative dynamics in doped manganite films: phonon anomalies in the ferromagnetic state

We present optical measurements of phononic excitations in La$_{2/3}$Ca$_{1/3}$MnO$_{3}$ (LCMO) and La$_{2/3}$Sr$_{1/3}$MnO$_{3}$ (LSMO) thin films covering the full temperature range from the metallic ferromagnetic to the insulating paramagnetic phase. All eight phonons expected for the R$\bar{3}$c symmetry in LSMO and 17 out of the expected 25 phonons for the Pnma symmetry in LCMO have been determined. Close to the ferromagnetic-to-paramagnetic transition both compounds reveal an anomalous behavior but with different characteristics. Anomalies in the phononic spectra are a manifestation of the coupling of lattice degrees of freedom (DOF) to electronic DOF. Specifically, the low-frequency external group proves to be an indicator for lattice modifications induced by electronic correlations. The enhanced electron-phonon coupling in LCMO is responsible for Fano-like interference effects of distinct phonon modes with electronic continuum excitations: we observe asymmetric phonon line shapes, mode splitting and spectral weight transfer between modes.Comment: 10 pages, 10 figure

Large and Small Polaron Excitations in La2/3(Sr/Ca)1/3MnO3 Films

We present detailed optical measurements of the mid-infrared (MIR) excitations in thin films of La2/3Sr1/3MnO3 (LSMO) and La2/3Ca1/3MnO3 (LCMO) across the magnetic transition. The shape of the excitation at about 0.2 eV in both samples is analyzed in terms of polaron models. We propose to identify the MIR resonance in LSMO as the excitation of large polarons and that in LCMO as a small polaron excitation. A scaling behavior for the low-energy side of the polaronic MIR resonance in LSMO is established

Deciphering satellite observations of compressional ULF waveguide modes

T. Elsden would like to thank STFC for financial support for a doctoral training grant, number AMC3 STFC12. A.N. Wright was supported by STFC grant ST/N000609/1.We present an analytical method for determining incident and reflection co- efficients for flank ULF compressional waveguide modes in Earth’s magnetosphere. In the flank magnetosphere, compressional waves propagate azimuthally, but exhibit a mixed standing/propagating nature radially. Understanding this radial dependence will yield information on the energy absorption and transport of these waves. We provide a step by step method that can be applied to observations of flank ULF waves, which separates these fluctuations into incident and reflected parts. As a means of testing, we apply the method to data from a numerical waveguide simulation, which shows the effect on the reflection coefficient when energy is absorbed at a field line resonance.Publisher PDFPeer reviewe

Metabolization of [Ru(η6-C6H5CF3)(pta)Cl2]: a cytotoxic RAPTA-type complex with a strongly electron withdrawing arene ligand

The anticancer ruthenium-arene compound [Ru(η6-C6H5CF3)(pta)Cl2] (where pta is 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane), termed RAPTA-CF3, with the electron-withdrawing α,α,α-trifluorotoluene ligand, is one of the most cytotoxic RAPTA compounds known. To rationalize the high observed cytotoxicity, the hydrolysis of RAPTA-CF3 in water and brine (100mM sodium chloride) and its reactions with the protein ubiquitin and a double-stranded oligonucleotide (5′-GTATTGGCACGTA-3′) were studied using NMR spectroscopy, high-resolution Fourier transform ion cyclotron resonance mass spectrometry, and gel electrophoresis. The aquation of the ruthenium-chlorido complex was accompanied by a loss of the arene ligand, independent of the chloride concentration, which is a special property of the compound not observed for other ruthenium-arene complexes with relatively stable ruthenium-arene bonds. Accordingly, the mass spectra of the biomolecule reaction mixtures contained mostly [Ru(pta)]-biomolecule adducts, whereas [Ru(pta)(arene)] adducts typical of other RAPTA compounds were not observed in the protein or DNA binding studies. Gel electrophoresis experiments revealed a significant degree of decomposition of the oligonucleotide, which was more pronounced in the case of RAPTA-CF3 compared with RAPTA-C. Consequently, facile arene loss appears to be responsible for the increased cytotoxicity of RAPTA-CF3. Graphical abstract: RAPTA-CF3 is a fast-acting cytotoxic compound that degrades DNA and has a mode of action fundamentally different from that of other ruthenium(II)-arene compound

Dynamic conductivity of semiconducting manganites approaching the metal-insulator transition

We report the frequency-dependent conductivity of the manganite system La1-xSrxMnO3 (x <= 0.2) when approaching the metal-insulator transition from the insulating side. Results from low-frequency dielectric measurements are combined with spectra in the infrared region. For low doping levels the behavior is dominated by hopping transport of localized charge carriers at low frequencies and by phononic and electronic excitations in the infrared region. For the higher Sr contents the approach of the metallic state is accompanied by the successive suppression of the hopping contribution at low frequencies and by the development of polaronic excitations in the infrared region, which finally become superimposed by a strong Drude contribution in the fully metallic state.Comment: 10 pages, 7 figure

Ruthenium versus platinum: interactions of anticancer metallodrugs with duplex oligonucleotides characterised by electrospray ionisation mass spectrometry

The binding of the ruthenium-based anticancer drug candidates KP1019, NAMI-A and RAPTA-T towards different double-stranded oligonucleotides was probed by electrospray ionisation mass spectrometry and compared with that of the widely used platinum-based chemotherapeutics cisplatin, carboplatin and oxaliplatin. It was found that the extent of adduct formation decreased in the following order: cisplatin>oxaliplatin>NAMI-A>RAPTA-T>carboplatin>KP1019. In addition to the characterisation of the adducts formed with the DNA models, the binding sites of the metallodrugs on the oligonucleotides were elucidated employing top-down tandem mass spectrometry and were found to be similar for all the metallodrugs studied, irrespective of the sequence of the oligonucleotide. A strong preference for guanine residues was establishe