Entgrenzung durch Medien: Internationalisierungsprozesse als Rahmenbedingung der Mediendidaktik

Die Mediendidaktik ist eine Teildisziplin der Medienpädagogik und hat in den vergangenen Jahren einen enormen Zuwachs an Nachfrage und Bedeutung erfahren. Dieser Bedeutungszuwachs ist bedingt durch den verstärkten Einsatz digitaler Informations- und Kommunikationstechniken in Bildungsprozessen (Stichwort «E- Learning»). Der vorliegende Beitrag entwickelt die These, dass die Mediendidaktik ausgehend von medientechnischen Entwicklungen im Kontext von Globalisierung einer Entgrenzung unterworfen ist. Diese Entgrenzung ist Chance und Risiko zugleich. Der vorliegende Beitrag klärt zunächst den Begriff der Entgrenzung. Anhand dreier Phänomene werden Prozesse der Entgrenzung für die Mediendidaktik beschrieben. Ausgehend von der Problematisierung der Prozesse von Entgrenzung werden abschliessend einige Folgerungen für die Mediendidaktik als Teildisziplin der Medienpädagogik zur Diskussion gestellt

The Double Path of Expansive Learning in Complex Socio-Technical Change Processes

The purpose of this article is to describe how expansive learning in organisations can become a resource for learning in a wider community of practice (CoP). The “developmental work research” approach (DWR) based on cultural historical activity theory (CHAT) is beneficial for analysing and interpreting the requirements in a field of action. Engeström’s specific form of “action research” focuses on expansive learning in activity systems. However, complex socio-technical change processes cannot be initiated and managed by the local community of practise alone. In order to establish the use of new tools, new methodologies or organisational solutions in a field of work, a double path of expansive learning is needed: Findings from the participative analysis and interpretation of contradictions in the local activity system have to be transferred to wider communities of practice. This paper illustrates a double path of expansive learning by presenting the experiences of research and development in machine and plant engineering companies in Germany. In the AQUIMO project, a project team has developed an adaptable software tool for multidisciplinary mechatronical engineering and created a related qualification program. The support from external social researchers has helped to initiate, disseminate and establish new ways to organise the division of labour in teams of engineers.</p

Inherited and flatband-induced ordering in twisted graphene bilayers

The nature of the insulating and superconducting states in twisted bilayer graphene systems is intensely debated. While many works seek for explanations in the few flat bands near the Fermi level, theory and a number of experiments suggest that nontwisted bilayer graphene systems do exhibit - or are at least close to - an ordered, insulating ground state related to antiferromagnetic ordering. Here we investigate in which ways this magnetic ordering scenario is affected by the slight twisting between the layers. We find that at charge neutrality the ordering tendencies of twisted systems interpolate between those of untwisted AA and AB stacked bilayers at intermediate temperatures, while at lower temperatures of the order of typical flat-band dispersion energies, the ordering tendencies are even enhanced for the twisted systems. The preferred order at charge neutrality still exhibits an antiferromagnetic spin arrangement, with ordered moments alternating on the carbon-carbon bonds, with an enveloping variation on the moir\'e scale. This ordering can be understood as inherited from the untwisted systems. However, even in the RPA analysis, the possible low-energy behaviors are quite versatile, and slight doping of one or more electrons per moir\'e cell can take the system into a, potentially flat-band induced, ferromagnetic phase.Comment: 8 pages, 9 figure

The Double Path of Expansive Learning in Complex Socio-Technical Change Processes

The purpose of this article is to describe how expansive learning in organisations can become a resource for learning in a wider community of practice (CoP). The “developmental work research” approach (DWR) based on cultural historical activity theory (CHAT) is beneficial for analysing and interpreting the requirements in a field of action. Engeström’s specific form of “action research” focuses on expansive learning in activity systems. However, complex socio-technical change processes cannot be initiated and managed by the local community of practise alone. In order to establish the use of new tools, new methodologies or organisational solutions in a field of work, a double path of expansive learning is needed: Findings from the participative analysis and interpretation of contradictions in the local activity system have to be transferred to wider communities of practice. This paper illustrates a double path of expansive learning by presenting the experiences of research and development in machine and plant engineering companies in Germany. In the AQUIMO project, a project team has developed an adaptable software tool for multidisciplinary mechatronical engineering and created a related qualification program. The support from external social researchers has helped to initiate, disseminate and establish new ways to organise the division of labour in teams of engineers

Functional renormalization group for a large moir\'e unit cell

Layers of two-dimensional materials arranged at a twist angle with respect to each other lead to enlarged unit cells with potentially strongly altered band structures, offering a new arena for novel and engineered many-body ground states. For the exploration of these, renormalization group methods are an appropriate, flexible tool that take into account the mutual influence of competing tendencies. Here we show that, within reasonable, non-trivial approximations, the functional renormalization group known from simpler two-dimensional systems can be employed for the large-unit cell moir\'e superlattices with more than 10.000 bands, remedying the need to employ ad hoc restrictions to effective low-energy theories of a few bands and/or effective continuum theories. This provides a description on the atomic scale, allowing one to absorb available ab-initio information on the model parameters and therefore lending the analysis a more concrete quantitative character. For the case of twisted bilayer graphene models, we explore the leading ordering tendencies depending on the band filling and the range of interactions. The results indicate a delicate balance between distinct magnetically ordered ground states, as well as the occurrence of a charge modulation within the moir\'e unit cell for sufficiently non-local repulsive interaction.Comment: 9 pages, 8 figure

Competition of Density Waves and Superconductivity in Twisted Tungsten Diselenide

Evidence for correlated insulating and superconducting phases around regions of high density of states was reported in the strongly spin-orbit coupled van-der Waals material twisted tungsten diselenide (tWSe2). We investigate their origin and interplay by using a functional renormalization group approach that allows to describe superconducting and spin/charge instabilities in an unbiased way. We map out the phase diagram as function of filling and perpendicular electric field, and find that the moiré Hubbard model for tWSe2 features mixed-parity superconducting order parameters with s/f-wave and topological d/p-wave symmetry next to (incommensurate) density wave states. Our work systematically characterizes competing interaction-driven phases in tWSe2 beyond mean-field approximations and provides guidance for experimental measurements by outlining the fingerprint of correlated states in interacting susceptibilities

Spin-fluctuation-induced pairing in twisted bilayer graphene

We investigate the interplay of magnetic fluctuations and Cooper pairing in twisted bilayer graphene from a purely microscopic model within a large-scale tight-binding approach resolving the \AA ngstr\"om scale. For local onsite repulsive interactions and using the random-phase approximation for spin fluctuations, we derive a microscopic effective pairing interaction that we use for self-consistent solutions of the Bogoliubov-de-Gennes equations of superconductivity. We study the predominant pairing types as function of interaction strength, temperature and band filling. For large regions of this parameter space, we find chiral $d$-wave pairing regimes, spontaneously breaking time-reversal symmetry, separated by magnetic instabilities at integer band fillings. Interestingly, the $d$-wave pairing is strongly concentrated in the AA regions of the moir\'e unit cell and exhibits phase windings of integer multiples of $2\pi$ around these superconducting islands, i.e. pinned vortices. The spontaneous circulating current creates a distinctive magnetic field pattern. This signature of the chiral pairing should be measurable by state-of-the-art experimental techniques.Comment: 5 pages, 3 figure

Qualitative Methodentriangulation bei der arbeitswissenschaftlichen Exploration von Tätigkeitssystemen

Research concerning ergonomic issues in interdisciplinary projects often raises several very specific questions depending on project objectives. To answer these questions the application of research methods should be thoroughly considered, regarding both the expenditure and the options within the scope of the given resources. The project AQUIMO develops an adaptable modelling tool for mechatronical engineering and creates a related qualification program. The task of social scientific research within this project is to identify requirements viewed from the perspective of the subsequent users. This formative evaluation is based on the approach of "developmental work research" as set forth by ENGESTRÖM and, thus, is a form of "action research". This paper discusses the triangulation of several qualitative methods addressing the examination of difficulties in interdisciplinary collaboration in mechatronical engineering. After a description of both background and analytic approach within the project AQUIMO, the methods are briefly described concerning their advantages and critical points. Their application within the research project AQUIMO is explained from an activity theoretical perspective. URN: urn:nbn:de:0114-fqs0803158A menudo surgen preguntas diversas y muy específicas en la investigación sobre temas ergonómicos en proyectos interdisciplinarios. Para responder tales preguntas debe considerarse cuidadosamente la aplicación de métodos de investigación, observando tanto los gastos como las opciones en el marco de los recursos disponibles. El proyecto AQUIMO desarrolla una adaptable herramienta de modelamiento para la ingeniería mecatrónica y crea un programa de calificación vinculado. La tarea de la investigación científica social en este proyecto es identificar las necesidades vistas desde la perspectiva de los usuarios. Esta evaluación formativa se basa en el enfoque de "trabajo de investigación para el desarrollo" formulado por ENGESTRÖM y, por ello, es una forma de "investigación acción". Este artículo discute la triangulación de varios métodos cualitativos examinando las dificultades de la colaboración interdisciplinaria en la ingeniería mecatrónica. Luego de la descripción de los antecedentes y del enfoque analítico en el proyecto AQUIMO, se describen brevemente los métodos de acuerdo con sus ventajas y puntos críticos. Se explica su aplicación en el proyecto de investigación AQUIMO desde una perspectiva teórica de la actividad. URN: urn:nbn:de:0114-fqs0803158Arbeitswissenschaftliche Aufgabenstellungen in interdisziplinären Projekten zeichnen sich häufig dadurch aus, dass sie entsprechend des Projektauftrages mehrere sehr spezifische Fragestellungen aufwerfen, deren Beantwortung im Rahmen der gegebenen Ressourcen eine sorgfältige Abwägung des Methodeneinsatzes hinsichtlich des Aufwandes und der Möglichkeiten erforderlich macht. Im Projekt AQUIMO sollen durch sozialwissenschaftliche Begleitforschung Anforderungen für die ingenieurwissenschaftliche Entwicklung eines computerbasierten Werkzeuges zur Unterstützung des mechatronischen Konstruktionsprozesses und einer dazugehörigen Qualifizierungsmaßnahme abgeleitet werden. Die formative Evaluation gründet auf dem Ansatz der entwickelnden Arbeitsforschung nach ENGESTRÖM und ist damit eine Form der Aktionsforschung. Der Beitrag befasst sich mit der Triangulation mehrerer qualitativer Methoden zur Untersuchung von Schwierigkeiten in der interdisziplinären Zusammenarbeit bei der mechatronischen Konstruktionstätigkeit. Nach einer Beschreibung der Ausgangslage und des Analyseansatzes im Projekt werden die Methoden hinsichtlich ihrer Vorzüge und kritischen Punkte jeweils kurz dargestellt und ihr Einsatz im Rahmen des Projektes AQUIMO aus tätigkeitstheoretischer Perspektive begründet. URN: urn:nbn:de:0114-fqs080315

Serum antibodies in first-degree relatives of patients with IBD: A marker of disease susceptibility? A follow-up pilot-study after 7 years

Introduction: Various disease-specific serum antibodies were described in patients with inflammatory bowel disease and their yet healthy first-degree relatives. In the latter, serum antibodies are commonly regarded as potential markers of disease susceptibility. The present long-term follow-up study evaluated the fate of antibody-positive first-degree relatives. Patients and Methods: 25 patients with Crohn's disease, 19 patients with ulcerative colitis and 102 first-degree relatives in whom presence of ASCA, pANCA, pancreatic- and goblet-cell antibodies had been assessed were enrolled. The number of incident cases with inflammatory bowel disease was compared between antibody-positive and antibody-negative first-degree relatives 7 years after storage of serum samples. Results: 34 of 102 (33%) first-degree relatives were positive for at least one of the studied serum antibodies. In the group of first-degree relatives, one case of Crohn's disease and one case of ulcerative colitis were diagnosed during the follow-up period. However, both relatives did not display any of the investigated serum antibodies (p = 1). Discussion: The findings of our pilot study argue against a role of serum antibodies as a marker of disease susceptibility in first-degree relatives of patients with inflammatory bowel disease. However, these data have to await confirmation in larger ideally prospective multicenter studies before definite conclusions can be drawn

Serum antibodies in first-degree relatives of patients with IBD: A marker of disease susceptibility? A follow-up pilot-study after 7 years

Introduction: Various disease-specific serum antibodies were described in patients with inflammatory bowel disease and their yet healthy first-degree relatives. In the latter, serum antibodies are commonly regarded as potential markers of disease susceptibility. The present long-term follow-up study evaluated the fate of antibody-positive first-degree relatives. Patients and Methods: 25 patients with Crohn's disease, 19 patients with ulcerative colitis and 102 first-degree relatives in whom presence of ASCA, pANCA, pancreatic- and goblet-cell antibodies had been assessed were enrolled. The number of incident cases with inflammatory bowel disease was compared between antibody-positive and antibody-negative first-degree relatives 7 years after storage of serum samples. Results: 34 of 102 (33%) first-degree relatives were positive for at least one of the studied serum antibodies. In the group of first-degree relatives, one case of Crohn's disease and one case of ulcerative colitis were diagnosed during the follow-up period. However, both relatives did not display any of the investigated serum antibodies (p = 1). Discussion: The findings of our pilot study argue against a role of serum antibodies as a marker of disease susceptibility in first-degree relatives of patients with inflammatory bowel disease. However, these data have to await confirmation in larger ideally prospective multicenter studies before definite conclusions can be drawn