Filtern
Volltext vorhanden
- ja (36) (entfernen)
Erscheinungsjahr
- 2003 (36) (entfernen)
Dokumenttyp
- Postprint (36) (entfernen)
Sprache
- Deutsch (25)
- Englisch (8)
- Französisch (3)
Schlagworte
- Germany (3)
- Theologie (3)
- transatlantic relations (3)
- Biogenic amine (2)
- European foreign policy (2)
- Flow-Erleben (2)
- G protein-coupled receptor (2)
- Iraq war (2)
- US foreign policy (2)
- ethnicity (2)
Institut
- Extern (10)
- Department Erziehungswissenschaft (8)
- Department Psychologie (5)
- Institut für Biochemie und Biologie (3)
- Institut für Chemie (3)
- Institut für Religionswissenschaft (3)
- Institut für Mathematik (2)
- Department für Inklusionspädagogik (1)
- Institut für Anglistik und Amerikanistik (1)
- Universitätsbibliothek (1)
Die Untersuchung "Gymnasio und Lykio in Griechenland. Ergebnisse einer Längsschnittuntersuchung, Kritik und Perspektiven" wurde von Panajotis Xochellis, Universität Thessaloniki, und Diether Hopf, Max-Planck-Institut für Bildungsforschung, 1980 begonnen und nach drei Messzeitpunkten mit einer letzten Datenerhebung im Schuljahr 2000/2001 abgeschlossen. Es geht um die Entwicklung ausgewählter Schulen in einem 20-jährigen Zeitraum, wobei Daten aus einer Vielzahl von Perspektiven erhoben wurden: Neben Informationen aus der allgemeinen griechischen Bildungsstatistik wurden die Schulleiter der Schulen befragt und interviewt, Lehrer füllten Fragebögen aus und ließen ihren Unterricht beobachten, außerdem wurden Schüler ausführlich befragt. Inhaltlich stehen die folgenden Themen im Vordergrund: Didaktik und Methodik in 5 Fächern (Neugriechisch, Altgriechisch, Geschichte, Mathematik, Physik), Leistungsbeurteilung und Übergangsauslese zum tertiären Sektor, Schul- und Unterrichtsklima, Motivation und Interessen der Schüler. Außerdem werden strukturelle Daten über das griechische Sekundarschulwesen insgesamt mit Bezug auf die untersuchten Schulen interpretiert und in den Zusammenhang mit internationalen Leistungsstudien (z.B. PISA) gestellt. Variablen wie Geschlecht der Schüler und Lehrer oder sozioökonomischer Status finden ebenfalls Berücksichtigung. Insgesamt ergibt sich eine Fülle interessanter Resultate, die teilweise von erheblicher bildungspolitischer Relevanz sind.
We question the assumption of serial attention shifts and the assumption that saccade programs are initiated or canceled only after stage one of word identification. Evidence: (1) Fixation durations prior to skipped words are not consistently higher compared to those prior to nonskipped words. (2) Attentional modulation of microsaccade rate might occur after early visual processing. Saccades are probably triggered by attentional selection.
Computational models such as E-Z Reader and SWIFT are ideal theoretical tools to test quantitatively our current understanding of eye-movement control in reading. Here we present a mathematical analysis of word skipping in the E-Z Reader model by semianalytic methods, to highlight the differences in current modeling approaches. In E-Z Reader, the word identification system must outperform the oculomotor system to induce word skipping. In SWIFT, there is competition among words to be selected as a saccade target. We conclude that it is the question of competitors in the “game” of word skipping that must be solved in eye movement research.
Adieu à l'école unique socialiste : transformations de l'école en Allemagne après la réunification
(2003)
Biogenic amines and their receptors regulate and modulate many physiological and behavioural processes in animals. In vertebrates, octopamine is only found in trace amounts and its function as a true neurotransmitter is unclear. In protostomes, however, octopamine can act as neurotransmitter, neuromodulator and neurohormone. In the honeybee, octopamine acts as a neuromodulator and is involved in learning and memory formation. The identification of potential octopamine receptors is decisive for an understanding of the cellular pathways involved in mediating the effects of octopamine. Here we report the cloning and functional characterization of the first octopamine receptor from the honeybee, Apis mellifera . The gene was isolated from a brain-specific cDNA library. It encodes a protein most closely related to octopamine receptors from Drosophila melanogaster and Lymnea stagnalis . Signalling properties of the cloned receptor were studied in transiently transfected human embryonic kidney (HEK) 293 cells. Nanomolar to micromolar concentrations of octopamine induced oscillatory increases in the intracellular Ca2+ concentration. In contrast to octopamine, tyramine only elicited Ca2+ responses at micromolar concentrations. The gene is abundantly expressed in many somata of the honeybee brain, suggesting that this octopamine receptor is involved in the processing of sensory inputs, antennal motor outputs and higher-order brain functions.
Dopamine is found in many invertebrate organisms, including insects, however, the mechanisms through which this amine operates remain unclear. We have expressed two dopamine receptors cloned from honey bee (AmDOP1 and AmDOP2) in insect cells (Spodoptera frugiperda), and compared their pharmacology directly using production of cAMP as a functional assay. In each assay, AmDOP1 receptors required lower concentrations of dopamine and 6,7-ADTN for maximal activation than AmDOP2 receptors. Conversely, butaclamol and cis(Z)-flupentixol were more potent at blocking the cAMP response mediated through AmDOP2 than AmDOP1 receptors. Expression of AmDOP1, but not AmDOP2, receptors significantly increased levels of cAMP even in the absence of ligand. This constitutive activity was blocked by cis(Z)-flupentixol. This work provides the first evidence of a constitutively activated dopamine receptor in invertebrates and suggests that although AmDOP1 and AmDOP2 share much less homology than their vertebrate counterparts, they display a number of functional parallels with the mammalian D1-like dopamine receptors.
Electro-chemical signal transduction is the basis of communication between n eurons and their target cells. An important group of neuroactive substances that are released by action potentials from neurons are the biogenic amines. These a re small organic molecules that bind to specific receptors located in the target cell membrane. Once activated these receptors cause changes in the intracellula r concentration of second messengers, i.e. cyclic nucleotides, phosphoinositides , or Ca2+, leading to slow but long-lasting cellular responses. Biochemical, pha rmacological, physiological, and molecular biological approaches have unequivoca lly shown that biogenic amines are important regulators of cellular function in both vertebrates and invertebrates. In this review, we will concentrate on the p roperties of two biogenic amines and their receptors that were originally identi fied in invertebrates: tyramine and octopamine.
(aus dem Inhalt): Ansätze zum problembasierten Lernen rücken didaktische Begründungen und pädagogische Handlungsmöglichkeiten in den Vordergrund von E-Learning-Konzepten. Der problembasierte Ansatz nimmt seinen Ausgangspunkt in praktischen Problemstellungen, zielt auf erfolgreiche Praxis und ist deshalb besonders für betriebliche Praktiker interessant. Angenommen wird, dass durch das Zugrundelegen von Problemen im Lehr-, Lernprozess Motivation unterstützt, Lerneraktivität gefördert und der Erwerb transferfähigeren Wissens und Könnens verbessert wird. Komplexe, realitätsnahe und subjektiv bedeutsame Problemstellungen sollen ein kognitiver und motivationaler Stimulus für das Lernen sein. Sind diese Hoffnungen begründet?
Investigations with frequency domain photon density waves allow elucidation of absorption and scattering properties of turbid media. The temporal and spatial propagation of intensity modulated light with frequencies up to more than 1 GHz can be described by the P1 approximation to the Boltzmann transport equation. In this study, we establish requirements for the appropriate choice of turbid model media and characterize mixtures of isosulfan blue as absorber and polystyrene beads as scatterer. For these model media, the independent determination of absorption and reduced scattering coefficients over large absorber and scatterer concentration ranges is demonstrated with a frequency domain photon density wave spectrometer employing intensity and phase measurements at various modulation frequencies.