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Die im Französischunterricht an Deutschsprachige zu vermittelnden Kategorien der Verbalflexion
(2000)
Im Mittelpunkt des Beitrags steht eine sprachwissenschaftlich verantwortete Beschreibung der im Französischunterricht auf der Sekundarstufe I zu unterrichtenden grammatischen Kategorien der Verbalflexion. Aufgrund der Mängel in verbreiteten Lehrwerken erscheint es dringend notwendig, nachvollziehbare Empfehlungen zu den Tempora und Modi vorzulegen. Mein Vorschlag richtet sich in erster Linie an Lehrplan- und Lehrwerkautoren.
On peut qualifier les hyperlivres de matériaux d'enseignement et d'apprentissage innovants bâtis sur une structuration électronique des éléments du savoir. En lieu et place du texte écrit est créée une base de données, dans laquelle le texte, les schémas et le son sont organisés de façon numérique. C'est dans ce lien entre des données habituellement dissociées que réside la plus-value de qualité apportée par le média. L'hyperlivre dont il est question ici prépare les étudiants à la langue de spécialité juridique, ce qui leur permet d'aborder sans trop de difficultés les séminaires de leur cursus intégré de droit français et de droit allemand. De plus, il permet des compléments en auto-formation et en approfondissement des notions abordées dans une discipline qui n'est pas toujours facile d'accès pour les apprenants.
Untersucht werden die Wirkungen unterschiedlicher Trainingsprogramme für Kinder mit Lernstörungen. - Im Motivationstraining werden das Zielsetzungsverhalten und die Attribution trainiert. - Das metakognitive Strategietraining trainiert die Orientierung, Planung, Temporegulation und Selbstkontrolle bei Lernaufgaben. Das Motivations- und das Strategietraining arbeiten mit unterrichtsstoff-unabhängigen Inhalten. Erst später erfolgt eine Übertragung auf den Schulunterricht. - Ein Rechtschreiblerntraining fördert die Motivation und metakognitive Strategien in Rechtschreibung, also am möglicherweise aversiv besetzten Inhalt, aber auch mit der Chance, dass die Kinder ihre negativen Lernerfahrungen bald als Irrtum einordnen können. Diese drei Trainingsprogramme werden in Kleingruppen realisiert. - Ein "Unterrichtsintegriertes Training" trainiert die Motivation und metakognitive Strategien im Klassenunterricht. Die Programme wurden bei Kindern im Alter von 9 bis 12 Jahre mit sonderpädagogischem Förderbedarf im Lernen eingesetzt. Der IQ der Schüler lag zwischen 80 und 100. Die Schüler waren in ihrem Lernen entmutigt und realisierten ineffektive Lernstrategien. Lese-Rechtschreibschwäche oder Rechenschwäche wurden ausgeschlossen. Als Effektvariable wurden kognitive, metakognitive und motivationale Maße erhoben, aber auch das Verhalten bei Schwierigkeitserleben. Kontrolliert wurden sowohl die unmittelbaren Trainingswirkungen als auch die Langzeitwirkungen nach 3 bis 6 Monaten. Darüber hinaus wurden differenzielle Effekte erfasst. Alle Trainingsprogramme erreichten gute Effektstärken in kognitiven und metakognitiven Variablen. Eine gute Ermutigungswirkung erzielten allerdings nur das Motivations- und das Strategietraining. Diese Ermutigungswirkung wiederum erwies sich als entscheidend für die Nachhaltigkeit und Anwendung gelernter Strategien bei Schwierigkeitserleben. Verallgemeinert erfordert ein Trainingserfolg folgende Bedingungen: 1. Verbindung des Trainings von Motivation und Lernstrategien. 2. Realisierung eines Intensivtrainings, in dem die Ressourcen des Kindes aktiviert werden. 3. Festigung der gelernten Strategien über einen längeren Zeitraum und Anwendung im Schulunterricht.
Die 'Repräsentativstudie zum Drogenkonsum Potsdamer Jugendlicher 2002' ist eine Querschnittsstudie. Es wurden Art und Umfang des Drogenkonsums der Jugendlichen im Alter von 14 bis 18 Jahren, die in der Stadt Potsdam zur Zeit der Befragung wohnhaft waren, untersucht, im besonderem die Lifetime-Prävalenz, das Erstkonsumalter, 12-Monatsprävalenz, Konsumort, sozialer Kontext, Probierbereitschaft, Informationsquellen, Konsumwirkung sowie Probleme mit dem Drogenkonsum etc. Insgesamt kamen 953 Fragebögen zur Auswertung. Die enthaltenen Interpretationen dienen der Stadt Potsdam für langfristige Maßnahmen, die Drogenhilfe zu planen und durchzuführen.
Highly collimated, high velocity streams of hot plasma – the jets – are observed as a general phenomenon being found in a variety of astrophysical objects regarding their size and energy output. Known as jet sources are protostellar objects (T Tauri stars, embedded IR sources), galactic high energy sources ("microquasars"), and active galactic nuclei (extragalactic radio sources and quasars). Within the last two decades our knowledge regarding the processes involved in astro-physical jet formation has condensed in a kind of standard model. This is the scenario of a magnetohydrodynamically accelerated and collimated jet stream launched from the innermost part of an accretion disk close to the central object. Traditionally, the problem of jet formation is divided in two categories. One is the question how to collimate and accelerate an uncollimated low velocity disk wind into a jet. The second is the question how to initiate that outflow from a disk, i.e. how to turn accretion of matter into an ejection as a disk wind. My own work is mainly related to the first question, the collimation and acceleration process. Due to the complexity of both, the physical processes believed to be responsible for the jet launching and also the spatial configuration of the physical components of the jet source, the enigma of jet formation is not yet completely understood. On the theoretical side, there has been a substantial advancement during the last decade from purely station-ary models to time-dependent simulations lead by the vast increase of computer power. Observers, on the other hand, do not yet have the instruments at hand in order to spatially resolve observe the very jet origin. It can be expected that also the next years will yield a substantial improvement on both tracks of astrophysical research. Three-dimensional magnetohydrodynamic simu-lations will improve our understanding regarding the jet-disk interrelation and the time-dependent character of jet formation, the generation of the magnetic field in the jet source, and the interaction of the jet with the ambient medium. Another step will be the combina-tion of radiation transfer computations and magnetohydrodynamic simulations providing a direct link to the observations. At the same time, a new generation of telescopes (VLT, NGST) in combination with new instrumental techniques (IR-interferometry) will lead to a "quantum leap" in jet observation, as the resolution will then be sufficient in order to zoom into the innermost region of jet formation.
In a classical context, synchronization means adjustment of rhythms of self-sustained periodic oscillators due to their weak interaction. The history of synchronization goes back to the 17th century when the famous Dutch scientist Christiaan Huygens reported on his observation of synchronization of pendulum clocks: when two such clocks were put on a common support, their pendula moved in a perfect agreement. In rigorous terms, it means that due to coupling the clocks started to oscillate with identical frequencies and tightly related phases. Being, probably, the oldest scientifically studied nonlinear effect, synchronization was understood only in 1920-ies when E. V. Appleton and B. Van der Pol systematically - theoretically and experimentally - studied synchronization of triode generators. Since that the theory was well developed and found many applications. Nowadays it is well-known that certain systems, even rather simple ones, can exhibit chaotic behaviour. It means that their rhythms are irregular, and cannot be characterized only by one frequency. However, as is shown in the Habilitation work, one can extend the notion of phase for systems of this class as well and observe their synchronization, i.e., agreement of their (still irregular!) rhythms: due to very weak interaction there appear relations between the phases and average frequencies. This effect, called phase synchronization, was later confirmed in laboratory experiments of other scientific groups. Understanding of synchronization of irregular oscillators allowed us to address important problem of data analysis: how to reveal weak interaction between the systems if we cannot influence them, but can only passively observe, measuring some signals. This situation is very often encountered in biology, where synchronization phenomena appear on every level - from cells to macroscopic physiological systems; in normal states as well as in severe pathologies. With our methods we found that cardiovascular and respiratory systems in humans can adjust their rhythms; the strength of their interaction increases with maturation. Next, we used our algorithms to analyse brain activity of Parkinsonian patients. The results of this collaborative work with neuroscientists show that different brain areas synchronize just before the onset of pathological tremor. Morevoever, we succeeded in localization of brain areas responsible for tremor generation.
One of the classical ways to describe the dynamics of nonlinear systems is to analyze theur Fourier spectra. For periodic and quasiperiodic processes the Fourier spectrum consists purely of discrete delta-functions. On the contrary, the spectrum of a chaotic motion is marked by the presence of the continuous component. In this work, we describe the peculiar, neither regular nor completely chaotic state with so called singular-continuous power spectrum. Our investigations concern various cases from most different fields, where one meets the singular continuous (fractal) spectra. The examples include both the physical processes which can be reduced to iterated discrete mappings or even symbolic sequences, and the processes whose description is based on the ordinary or partial differential equations.
Line driven winds are accelerated by the momentum transfer from photons to a plasma, by absorption and scattering in numerous spectral lines. Line driving is most efficient for ultraviolet radiation, and at plasma temperatures from 10^4 K to 10^5 K. Astronomical objects which show line driven winds include stars of spectral type O, B, and A, Wolf-Rayet stars, and accretion disks over a wide range of scales, from disks in young stellar objects and cataclysmic variables to quasar disks. It is not yet possible to solve the full wind problem numerically, and treat the combined hydrodynamics, radiative transfer, and statistical equilibrium of these flows. The emphasis in the present writing is on wind hydrodynamics, with severe simplifications in the other two areas. I consider three topics in some detail, for reasons of personal involvement. 1. Wind instability, as caused by Doppler de-shadowing of gas parcels. The instability causes the wind gas to be compressed into dense shells enclosed by strong shocks. Fast clouds occur in the space between shells, and collide with the latter. This leads to X-ray flashes which may explain the observed X-ray emission from hot stars. 2. Wind runaway, as caused by a new type of radiative waves. The runaway may explain why observed line driven winds adopt fast, critical solutions instead of shallow (or breeze) solutions. Under certain conditions the wind settles on overloaded solutions, which show a broad deceleration region and kinks in their velocity law. 3. Magnetized winds, as launched from accretion disks around stars or in active galactic nuclei. Line driving is assisted by centrifugal forces along co-rotating poloidal magnetic field lines, and by Lorentz forces due to toroidal field gradients. A vortex sheet starting at the inner disk rim can lead to highly enhanced mass loss rates.
The behaviour of an adhering cell is strongly influenced by the chemical, topographical and mechanical properties of the surface it attaches to. During recent years, it has been found experimentally that adhering cells actively sense the elastic properties of their environment by pulling on it through numerous sites of adhesion. The resulting build-up of force at sites of adhesion depends on the elastic properties of the environment and is converted into corresponding biochemical signals, which can trigger cellular programmes like growth, differentiation, apoptosis, and migration. In general, force is an important regulator of biological systems, for example in hearing and touch, in wound healing, and in rolling adhesion of leukocytes on vessel walls. In the habilitation thesis by Ulrich Schwarz, several theoretical projects are presented which address the role of forces and elasticity in cell adhesion. (1) A new method has been developed for calculating cellular forces exerted at sites of focal adhesion on micro-patterned elastic substrates. The main result is that cell-matrix contacts function as mechanosensors, converting internal force into protein aggregation. (2) A one-step master equation for the stochastic dynamics of adhesion clusters as a function of cluster size, rebinding rate and force has been solved both analytically and numerically. Moreover this model has been applied to the regulation of cell-matrix contacts, to dynamic force spectroscopy, and to rolling adhesion. (3) Using linear elasticity theory and the concept of force dipoles, a model has been introduced and solved which predicts the positioning and orientation of mechanically active cells in soft material, in good agreement with experimental observations for fibroblasts on elastic substrates and in collagen gels.