“I feel enthusiastic, when the homework is done well”: teachers’ emotions related to homework and their antecedents

Emotions are an important factor influencing teaching behavior and teaching quality. Previous studies have primarily focused on teachers’ emotions in the classroom in general, rather than focusing on a specific aspect of teaching such as homework practice. Since emotions vary between situations, it can be assumed that teachers’ emotions also vary between the activities that teachers perform. In this study, we therefore focus on one specific teacher activity in our study, namely homework practice. We explore teachers’ emotions in homework practice and their antecedents. Methodologically, semi-structured interviews were conducted with 23 Swiss secondary school teachers teaching German and analysed using structuring qualitative content analysis. The results show that teachers experience a variety of positive and negative emotions related to homework practice, with positive emotions predominating. According to the teachers’ reflections, the antecedents of their emotions could be attributed to the context (e.g., conditions at home), teacher behavior and (inner) demands (e.g., perceived workload) and student behavior (e.g., learning progress). Implications for teacher education and training are discussed

Time reproduction during high and low attentional tasks in Alzheimer’s Disease “A watched kettle never boils”

A wealth of empirical evidence suggests that directing attention to temporal processing increases perceived duration, whereas drawing attention away from it has the opposite effect. Our work investigates this phenomenon by comparing perceived duration during a high attentional and a low attentional task in Alzheimer‟s Disease (AD) patients since these participants tend to show attentional deficits. In the high attentional task, AD patients and older adults were asked to perform the interference condition of the Stroop test for 15s while in the low attentional task, they had to fixate on a cross for the same length of time. In both conditions, participants were not aware they would be questioned about timing until the end of the task when they had to reproduce the duration of the previously-viewed stimulus. AD patients under-reproduced the duration of previously-exposed stimulus in the high attentional relative to the low attentional task, and the same pattern was observed in older adults. Due to their attentional deficits, AD patients might be overwhelmed by the demand of the high attentional task, leaving very few, if any, attentional resources for temporal processing

Prospects of Transition Interface Sampling simulations for the theoretical study of zeolite synthesis

The transition interface sampling (TIS) technique allows to overcome large free energy barriers within reasonable simulation time, which is impossible for straightforward molecular dynamics. Still, the method does not impose an artificial driving force, but it surmounts the timescale problem by an importance sampling of true dynamical pathways. Recently, it was shown that the efficiency of TIS to calculate reaction rates is less sensitive to the choice of reaction coordinate than those of the standard free energy based techniques. This could be an important advantage in complex systems for which a good reaction coordinate is usually very difficult to find. We explain the principles of this method and discuss some of the promising applications related to zeolite formation.Comment: 9 pages, accepted for publication in Phys. Chem. Chem. Phys. for the special issue of the CECAM workshop: Computational aspects of building blocks, nucleation, and synthesis of porous materials Aug. 29 2006 to Aug. 31 200

Filtre multicouche en bande C à résonateurs en boucle-ouverte carrée et plots métalliques flottants

National audienceL'évolution constante et rapide des systèmes de télécommunications conduit à rechercher des solutions hyperfréquences faibles coûts toujours plus performantes et de taille réduite. Afin de satisfaire aux spécifications très sévères des filtres, il est nécessaire d'associer des topologies adéquates, des outils de simulation précis et une technologie maîtrisée. A cet effet, les topologies à base de couplages croisés qui permettent de favoriser les couplages entre résonateurs non adjacents pour améliorer les performances, sont très attractives [1]. Une grande variété de formes de résonateurs planaires a été développée mais généralement implémentée pour des applications de filtre à bande étroite. En effet, pour des filtres plus large bande, des niveaux de couplage plus élevés sont nécessaires, ce qui se traduit par des distances inter-résonateurs très faibles. Une solution pratique pour résoudre cette difficulté est d'utiliser des structures multi niveaux [2]. Dans la littérature, la plupart des filtres multicouches décrits sont à bande étroite (bande passante relative inférieure à 10%), et l'objectif est clairement la réduction de taille. Cet article décrit un filtre présentant une bande passante de 22% et utilisant des résonateurs en boucle ouverte. Les niveaux élevés de couplage sont réalisés en considérant deux niveaux conducteurs et des plots métalliques flottants [3]. Notre objectif est d'illustrer les bénéfices d'une technologie multicouche au travers de la conception d'un filtre large-bande basée sur une approche de type matrice de couplage

\u3ci\u3eChlorella\u3c/i\u3e Viruses Evoke a Rapid Release of K\u3csup\u3e+\u3c/sup\u3e from Host Cells During the Early Phase of Infection

Infection of Chlorella NC64A cells by PBCV-1 produces a rapid depolarization of the host probably by incorporation of a viral-encoded K+ channel (Kcv) into the host membrane. To examine the effect of an elevated conductance, we monitored the virus-stimulated efflux of K+ from the Chlorella cells. The results indicate that all 8 Chlorella viruses tested evoked a host specific K+ efflux with a concomitant decrease in the intracellular K+. This K+ efflux is partially reduced by blockers of the Kcv channel. Qualitatively these results support the hypothesis that depolarization and K+ efflux are at least partially mediated by Kcv. The virus-triggered K+ efflux occurs in the same time frame as host cell wall degradation and ejection of viral DNA. Therefore, it is reasonable to postulate that loss of K+ and associated water fluxes from the host lower the pressure barrier to aid ejection of DNA from the virus particles into the host

Exploitation des couplages de proximité dans une topologie de filtres à stubs

National audienceParmi les nombreuses topologies de filtres décrites dans la littérature, la topologie Dual Behavior Resonator (DBR) apporte de nombreux avantages [1]. Elle permet un contrôle indépendant et simultané de la fréquence centrale et des bandes atténuées adjacentes. Ses caractéristiques particulières, ses degrés de liberté et sa souplesse, lui permettent de répondre aisément à des spécifications électriques sévères. Toutefois, comme pour les autres topologies classiques de filtres à stubs, un phénomène n'est pas pris en compte dans la synthèse : il s'agit des couplages de proximité apparaissant de façon fortuite entre les résonateurs adjacents ou non adjacents. Ces couplages non pris en compte par les synthèses traditionnelles influent beaucoup sur la réponse électrique des structures, et peuvent être de surcroît de nouveaux paramètres de réglage. Ce papier est consacré à l'exploitation des phénomènes de couplage pour améliorer les performances de la topologie DBR. Cela nécessite de définir et de mettre en oeuvre des techniques de synthèse adaptées pour maîtriser ces phénomènes

An Atypical Form of αB-crystallin Is Present in High Concentration in Some Human Cataractous Lenses IDENTIFICATION AND CHARACTERIZATION OF ABERRANT N- AND C-TERMINAL PROCESSING

Two unique polypeptides, 22.4 and 16.4 kDa, were prominent in some human cataracts. Both proteins were identified as modified forms of the small heat shock protein, αB-crystallin. The concentration of total αB-crystallin in most of these cataracts was significantly increased. The 22.4-kDa protein was subsequently designated as αBg. Mass spectrometric analyses of tryptic and Asp-N digests showed αBg is αB-crystallin minus the C-terminal lysine. αBg constituted 10–90% of the total αB-crystallin in these cataracts and was preferentially phosphorylated over the typical form of αB-crystallin. Human αBg and αB-crystallin were cloned and expressed inEscherichia coli. The differences in electrophoretic mobility and the large difference in native pI values suggest some structural differences exist. The chaperone-like activity of recombinant human αBg was comparable to that of recombinant human αB-crystallin in preventing the aggregation of lactalbumin induced by dithiothreitol. The mechanism involved in generating αBg is not known, but a premature termination of the αB-crystallin gene was ruled out by sequencing the polymerase chain reaction products of the last exon for the αB-crystallin gene from lenses containing αBg. The 16.4-kDa protein was an N-terminally truncated fragment of αBg. The high concentration of αB-crystallin in these cataracts is the first observation of this kind in human lenses

The HCN domain couples voltage gating andcAMP response in hyperpolarization-activatedcyclic nucleotide-gated channels

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control spontaneous electrical activity in heart and brain. Binding of cAMP to the cyclic nucleotide-binding domain (CNBD) facilitates channel opening by relieving a tonic inhibition exerted by the CNBD. Despite high resolution structures of the HCN1 channel in the cAMP bound and unbound states, the structural mechanism coupling ligand binding to channel gating is unknown. Here we show that the recently identified helical HCN-domain (HCND) mechanically couples the CNBD and channel voltage sensing domain (VSD), possibly acting as a sliding crank that converts the planar rotational movement of the CNBD into a rotational upward displacement of the VSD. This mode of operation and its impact on channel gating are confirmed by computational and experimental data showing that disruption of critical contacts between the three domains affects cAMP- and voltage-dependent gating in three HCN isoforms

The HCN domain couples voltage gating and cAMP response in hyperpolarization-activated cyclic nucleotide-gated channels

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control spontaneous electrical activity in heart and brain. Binding of cAMP to the cyclic nucleotide-binding domain (CNBD) facilitates channel opening by relieving a tonic inhibition exerted by the CNBD. Despite high resolution structures of the HCN1 channel in the cAMP bound and unbound states, the structural mechanism coupling ligand binding to channel gating is unknown. Here we show that the recently identified helical HCN-domain (HCND) mechanically couples the CNBD and channel voltage sensing domain (VSD), possibly acting as a sliding crank that converts the planar rotational movement of the CNBD into a rotational upward displacement of the VSD. This mode of operation and its impact on channel gating are confirmed by computational and experimental data showing that disruption of critical contacts between the three domains affects cAMP- and voltagedependent gating in three HCN isoforms

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis