Cognitive, social and emotional development

No abstract available

Domain-Specific Knowledge and Memory Performance: A Comparison of High- and Low-Aptitude Children

Two studies compared memory performance and text comprehension of groups that were equivalent on domain-specific knowledge but differed in overall aptitude, to investigate whether prior knowledge about a particular domain or overall aptitude level was more important when the task was to acquire and use new information in the domain of interest. Both studies dealt with third-, fifth-, and seventh-grade soccer experts' and novices' memory and comprehension of a story dealing with a soccer game. Several measures of memory performance, memory monitoring, and text comprehension were used. Levels of soccer knowledge and of overall aptitude were varied in a factorial design. Neither study detected significant differences between high-aptitude and low-aptitude experts, regardless of their ages. Low aptitude experts outperformed high-aptitude novices on all memory and comprehension measures. The results indicate that domain-specific knowledge can compensate for low overall aptitude on domain-related cognitive tasks

Gating NO Release from Nitric Oxide Synthase

We have investigated the kinetics of NO escape from Geobacillus stearothermophilus nitric oxide synthase (gsNOS). Previous work indicated that NO release was gated at position 223 in mammalian enzymes; our kinetics experiments include mutants at that position along with measurements on the wild type enzyme. Employing stopped-flow UV–vis methods, reactions were triggered by mixing a reduced enzyme/N-hydroxy-l-arginine complex with an aerated buffer solution. NO release kinetics were obtained for wt NOS and three mutants (H134S, I223V, H134S/I223V). We have confirmed that wt gsNOS has the lowest NO release rate of known NOS enzymes, whether bacterial or mammalian. We also have found that steric clashes at positions 223 and 134 hinder NO escape, as judged by enhanced rates in the single mutants. The empirical rate of NO release from the gsNOS double mutant (H134/I223V) is nearly as rapid as that of the fastest mammalian enzymes, demonstrating that both positions 223 and 134 function as gates for escape of the product diatomic molecule

On high-speed turning of a third-generation gamma titanium aluminide

Gamma titanium aluminides are heat-resistant intermetallic alloys predestined to be employed in components suffering from high mechanical stresses and thermal loads. These materials are regarded as difficult to cut, so this makes process adaptation essential in order to obtain high-quality and defect-free surfaces suitable for aerospace and automotive parts. In this paper, an innovative approach for longitudinal external high-speed turning of a third-generation Ti-45Al-8Nb- 0.2C-0.2B gamma titanium aluminide is presented. The experimental campaign has been executed with different process parameters, tool geometries and lubrication conditions. The results are discussed in terms of surface roughness/integrity, chip morphology, cutting forces and tool wear. Experimental evidence showed that, due to the high cutting speed, the high temperatures reached in the shear zone improve chip formation, so a crack-free surface can be obtained. Furthermore, the use of a cryogenic lubrication system has been identified in order to reduce the huge tool wear, which represents the main drawback when machining gamma titanium aluminides under the chosen process condition

'Der gute Lehrer', 'die gute Lehrerin' im Spiegel der Wissenschaft. Was macht Lehrende wirksam und was führt zu ihrer Wirksamkeit?

Seit mehr als einem Jahrhundert beschäftigt sich die pädagogisch-psychologische Forschung mit der Persönlichkeit von Lehrerinnen und Lehrern, ihrem pädagogischen Handeln, mit der Bedeutung didaktischer Expertise und den Wirkungen des Unterrichts auf das Erleben, Verhalten und Lernen der Schülerinnen und Schüler. Was ist der gegenwärtige Erkenntnisstand dieser vielfältigen empirischen Forschungsbemühungen? Gibt es "den guten Lehrer, "die gute Lehrerin" überhaupt, und, wenn ja, wodurch lassen sie sich charakterisieren? Sind bestimmte Persönlichkeitsmerkmale entscheidend, spielen wirksame Lehrtechniken die dominierende Rolle oder geht es bevorzugt um die professionalisierte Unterrichtsexpertise? Im Beitrag werden verschiedene Paradigmen der Lehrer- und der Lehrforschung dargestellt, der aktuelle wissenschaftliche Erkenntnisstand skizziert und einige Schlussfolgerungen für die Aus- und Weiterbildung von Lehrerinnen und Lehrern diskutiert

Statistical evaluation of SCADA data for wind turbine condition monitoring and farm assessment

Operational data from wind farms is crucial for wind turbine condition monitoring and performance assessment. In this paper, we analyse three wind farms with the aim to monitor environmental and operational conditions that might result in underperformance or failures. The assessment includes a simple wind speed characterisation and wake analysis. The evolution of statistical parameters is used to identify anomalous turbine behaviour. In total, 88 turbines and 12 failures are analysed, covering different component failures. Notwithstanding the short period of data available, several operational parameters are found to deviate from the farm trend in some turbines affected by failures. As a result, some parameters show better monitoring capabilities than others, for the detection of certain failures. However, the limitations of SCADA statistics are also shown as not all failures showed anomalies in the observed parameters

Nonthermal fragmentation of C60

A theoretical study of the subpicosecond fragmentation of C60 clusters in response to ultrafast laser pulses is presented. We simulate the laser excitation and the consequent nonequilibrium relaxation dynamics of the electronic and nuclear degrees of freedom. The first stages of the nonequilibrium dynamics are dominated by a coherent breathing mode followed by the cold ejection of single C atoms, in contrast to the dimer emission which characterizes the thermal relaxation. We also determine the nonequilibrium damage thresholds as a function of the pulse duration.Comment: 5 pages, 4 figures, submitted to Chem. Phys. Let