Flexibilität mit Risiko – nicht ohne Nebenwirkung:Situation und Perspektiven des Hauptfachs Erziehungs und Bildungswissenschaft: Schwerpunkt Erwachsenenbildung

Der Beitrag von Peter Faulstich und Gernot Graeßner basiert auf einem Text, der für die Veröffentlichung im „Datenreport Erziehungswissenschaft 2006“ (Reihe „Schriften der DGfE“, VS Verlag für Sozialwissenschaften) vorgesehen ist. Die Autoren analysieren die Ergebnisse einer Erhebung zum aktuellen Stand der Hauptfach-Studiengänge Erziehungs- und Bildungswissenschaft mit dem Schwerpunkt Erwachsenenbildung. Sie zeigen, dass die europaweite Umstellung auf Bachelor- und Master-Abschlüsse (Bologna-Prozess) in Deutschland erst in Ansätzen greift. Von 50 Hochschulen, die einen Schwerpunkt Erwachsenenbildung oder Weiterbildung in ihrem Profil verankert haben, bieten 33 den Diplom-Abschluss, sechs einen Bachelor, sieben einen Master und 14 einen Magister-Abschluss an. Diese Situation unterscheidet sich noch wenig von den 2001 bzw. 2004 durchgeführten Erhebungen. Bei den Weiterbildungsangeboten wurden sieben Programme weniger verzeichnet. Faulstich/Graeßner rechnen für 2006/2007 mit einer Welle von Umstellungen auf das konsekutive BA-/MA-Modell – bei gleichzeitigem Auslaufen der bisherigen Diplom- und Magisterstudiengänge. Die einzelnen Hochschulen setzen bei der Umstellung auf Bachelor- und Masterstudiengänge unterschiedliche Schwerpunkte (z. B. Konzentration auf Master-Studiengänge und Vernachlässigung des Bachelors). Am Beispiel ausgewählter Universitäten zeichnen die Autoren Konzepte, Entwicklung und Stand der Umsetzung nach. Faulstich/Graeßner warnen vor einer – sich bereits abzeichnenden – Destabilisierung des Hauptfachs Erziehungswissenschaft infolge des Bologna-Prozesses. Sie plädieren für eine gemeinsame Strategie der Hochschulen und empfehlen in den Bachelor-Studiengängen eine breite Grundlage zu schaffen, die die einzelnen Tätigkeitsschwerpunkte berücksichtigt, aber noch nicht zu sehr ausdifferenziert. In den Master-Studiengängen könnten dann – je nach Profil der einzelnen Hochschulen – unterschiedliche Modelle umgesetzt werden

Microplastics in Namibian river sediments – a first evaluation

The African continent is rarely the focus of microplastics research, although the ubiquity of microplastics in the environment is undisputed and still increasing. Due to the high production and use of plastic products and the partial lack of recycling systems in many parts of the African continent, it can be assumed that microplastic particles are already present in limnic and terrestrial ecosystems. Few studies, mainly from South Africa and the Northern African region, show a contamination with microplastics, especially in marine environments. This study aims to explore the presence and composition of microplastics in fluvial sediments of the major catchments in Namibia with a regional focus on the Iishana system in Northern Namibia, as one of the most densely populated areas in the country. In March 2019 and March 2021, at the end of the rainy seasons, sediments from the Iishana system and of the largest river catchments were sampled. Extraction was performed by density separation using the Microplastic Sediment Separator (MPSS) with the separation solution sodium chloride (density of 1.20 g/cm3). The particle size was determined by filtration and fractionation, and the polymer type by measurement with ATR-FTIR spectroscopy (minimum particle size 0.3 mm). Microplastics were found in the sediments of each river system, most of the particles in the Iishana system (average of 13.2 particles/kg dry weight). The perennial, the ephemeral rivers, and the Iishana system are similar concerning polymer type and particle size. Polyethylene and polypropylene were the dominant polymer types. Most of the particles were found in the size fractions 0.3 – 0.5 mm and 0.5 – 1.0 mm. The particles were found mainly as fragments and films, the majority transparent and brown

Hochschulisches Lernen – eine analytische Perspektive

Dieser Beitrag betrachtet hochschulisches Lernen unter einer analytischen Perspektive: Danach artikuliert sich hochschulisches Lernen im institutionellen Kontext der Hochschule mit ihren studiengangstrukturellen Rahmenbedingungen in einer je spezifischen, dabei stets kontingenten und polymorphen Koppelung zwischen Wissenschaft als Ort der Wissensproduktion einerseits und Studium als Ort der Erschliesung von Sinn- und Handlungsressourcen andererseits. Hochschulisches Lernen lasst sich als Moglichkeitsraum von Figurationen dieser Bezugnahmen rekonstruieren. Die Analyse des Lernens an Hochschulen erschliest auserdem Forschungsperspektiven einer bildungswissenschaftlichen Hochschulforschung und einer theoretischen Hochschuldidaktik, zu denen die Erwachsenenbildungswissenschaft substanzielle Beitrage liefern kann

Interacting models for twisted bilayer graphene: a quantum chemistry approach

The nature of correlated states in twisted bilayer graphene (TBG) at the magic angle has received intense attention in recent years. We present a numerical study of an interacting Bistritzer-MacDonald (IBM) model of TBG using a suite of methods in quantum chemistry, including Hartree-Fock, coupled cluster singles, doubles (CCSD), and perturbative triples (CCSD(T)), as well as a quantum chemistry formulation of the density matrix renormalization group method (DMRG). Our treatment of TBG is agnostic to gauge choices, and hence we present a new gauge-invariant formulation to detect the spontaneous symmetry breaking in interacting models. To benchmark our approach, we focus on a simplified spinless, valleyless IBM model. At integer filling ($\nu=0$), all numerical methods agree in terms of energy and $C_{2z} \mathcal{T}$ symmetry breaking. Additionally, as part of our benchmarking, we explore the impact of different schemes for removing ``double-counting'' in the IBM model. Our results at integer filling suggest that cross-validation of different IBM models may be needed for future studies of the TBG system. After benchmarking our approach at integer filling, we perform the first systematic study of the IBM model near integer filling (for $|\nu|< 0.2$). In this regime, we find that the ground state can be in a metallic and $C_{2z} \mathcal{T}$ symmetry breaking phase. The ground state appears to have low entropy, and therefore can be relatively well approximated by a single Slater determinant. Furthermore, we observe many low entropy states with energies very close to the ground state energy in the near integer filling regime

Screening of depression in adolescents through the Internet: Sensitivity and specificity of two screening questionnaires.

.001). The scores on both instruments were significantly increased in all subjects with a mood disorder, whether current or lifetime, except for lifetime minor depression. In the ROC analyses, high areas under the curve were found for the MDI (0.89) and CESD (0.90). The best cut-off point for the MDI was 19 (sensitivity: 90.48; specificity: 71.53), and for the CES-D it was 22 (sensitivity: 90.48; specificity: 74.31). We conclude that the MDI and CES-D are reliable and valid instruments that can be used for this screening

Hypoxia Alters Cell Cycle Regulatory Protein Expression and Induces Premature Maturation of Oligodendrocyte Precursor Cells

Periventricular white matter injury (PWMI) is a common form of brain injury sustained by preterm infants. A major factor that predisposes to PWMI is hypoxia. Because oligodendrocytes (OLs) are responsible for myelination of axons, abnormal OL development or function may affect brain myelination. At present our understanding of the influences of hypoxia on OL development is limited. To examine isolated effects of hypoxia on OLs, we examined the influences of hypoxia on OL development in vitro.Cultures of oligodendrocyte precursor cells (OPCs) were prepared from mixed glial cultures and were 99% pure. OPCs were maintained at 21% O(2) or hypoxia (1% or 4% O(2)) for up to 7 days. We observed that 1% O(2) lead to an increase in the proportion of myelin basic protein (MBP)-positive OLs after 1 week in culture, and a decrease in the proportion of platelet-derived growth factor receptor alpha (PDGFRalpha)-positive cells suggesting premature OL maturation. Increased expression of the cell cycle regulatory proteins p27(Kip1) and phospho-cdc2, which play a role in OL differentiation, was seen as well.These results show that hypoxia interferes with the normal process of OL differentiation by inducing premature OPC maturation

Mutation in Archain 1, a Subunit of COPI Coatomer Complex, Causes Diluted Coat Color and Purkinje Cell Degeneration

Intracellular trafficking is critical for delivering molecules and organelles to their proper destinations to carry out normal cellular functions. Disruption of intracellular trafficking has been implicated in the pathogenesis of various neurodegenerative disorders. In addition, a number of genes involved in vesicle/organelle trafficking are also essential for pigmentation, and loss of those genes is often associated with mouse coat-color dilution and human hypopigmentary disorders. Hence, we postulated that screening for mouse mutants with both neurological defects and coat-color dilution will help identify additional factors associated with intracellular trafficking in neuronal cells. In this study, we characterized a mouse mutant with a unique N-ethyl-N-nitrosourea (ENU)–induced mutation, named nur17. nur17 mutant mice exhibit both coat-color dilution and ataxia due to Purkinje cell degeneration in the cerebellum. By positional cloning, we identified that the nur17 mouse carries a T-to-C missense mutation in archain 1 (Arcn1) gene which encodes the δ subunit of the coat protein I (COPI) complex required for intracellular trafficking. Consistent with this function, we found that intracellular trafficking is disrupted in nur17 melanocytes. Moreover, the nur17 mutation leads to common characteristics of neurodegenerative disorders such as abnormal protein accumulation, ER stress, and neurofibrillary tangles. Our study documents for the first time the physiological consequences of the impairment of the ARCN1 function in the whole animal and demonstrates a direct association between ARCN1 and neurodegeneration

Evolutionarily Divergent, Unstable Filamentous Actin Is Essential for Gliding Motility in Apicomplexan Parasites

Apicomplexan parasites rely on a novel form of actin-based motility called gliding, which depends on parasite actin polymerization, to migrate through their hosts and invade cells. However, parasite actins are divergent both in sequence and function and only form short, unstable filaments in contrast to the stability of conventional actin filaments. The molecular basis for parasite actin filament instability and its relationship to gliding motility remain unresolved. We demonstrate that recombinant Toxoplasma (TgACTI) and Plasmodium (PfACTI and PfACTII) actins polymerized into very short filaments in vitro but were induced to form long, stable filaments by addition of equimolar levels of phalloidin. Parasite actins contain a conserved phalloidin-binding site as determined by molecular modeling and computational docking, yet vary in several residues that are predicted to impact filament stability. In particular, two residues were identified that form intermolecular contacts between different protomers in conventional actin filaments and these residues showed non-conservative differences in apicomplexan parasites. Substitution of divergent residues found in TgACTI with those from mammalian actin resulted in formation of longer, more stable filaments in vitro. Expression of these stabilized actins in T. gondii increased sensitivity to the actin-stabilizing compound jasplakinolide and disrupted normal gliding motility in the absence of treatment. These results identify the molecular basis for short, dynamic filaments in apicomplexan parasites and demonstrate that inherent instability of parasite actin filaments is a critical adaptation for gliding motility