Binnendifferenzierung und pädagogisches Handeln – Entwicklungsforschung an einer Brennpunktschule

In diesem Beitrag stellen wir ein Unterrichts- und Schulentwicklungsprojekt an einer sogenannten Brennpunktschule einer Großstadt vor, das sich zum Ziel setzt, gemeinsam mit den Lehrpersonen aus der Praxis ein Konzept der Binnendifferenzierung zu erarbeiten, welches zugleich das pädagogische Handeln stärker berücksichtigt als herkömmliche Ansätze. Im Zentrum unserer bisherigen 1,5-jährigen Arbeit steht dabei die Entwicklung der Schule bezogen auf den Mathematikunterricht in stark heterogenen Gruppen. In der (mathematik-)didaktischen Forschungslandschaft sind einige praxisbezogene Ansätze und Konzepte binnendifferenzierenden Unterrichts entstanden (z. B. Leuders & Prediger 2012). Eine derartige Schule ist allerdings in ihrer (Problem-)Struktur so komplex, dass Konzepte für Unterricht an die spezifischen Strukturen anknüpfen müssen, wenn sie erfolgreich sein sollen. Um dies zu erreichen, stellen wir uns der Komplexität in einem systemischen Zugang, welcher in einem Handlungsforschungsansatz auf evolutionäre Innovation (Reinmann 2005) ausgerichtet ist. In der praktischen Arbeit äußert sich dies in einer Form des fachspezifischen Unterrichtscoachings (Staub & Kreis 2013). Dabei übernehmen die Forscherinnen im Entwicklungs- und Unterrichtsprozess Mitverantwortung für die Gestaltungsarbeit. Die Datenerhebung erfolgt durch ethnographische Feldnotizen, dokumentarische Methoden und Interviews. Dabei liegt der Fokus auf der Erarbeitung eines Konzeptes zum binnendifferenzierten Mathematikunterricht unter den spezifischen Gegebenheiten und der Dokumentation des Entwicklungsprozesses aus verschiedenen Perspektiven – vornehmlich einer mathematikdidaktischen, pädagogischen und soziologischen Perspektive. Ziel des Artikels ist es, die Intention und Richtung der bisherigen Entwicklungsforschungsarbeit aufzuzeigen

Large-Scale Recombinant Production of the SARS-CoV-2 Proteome for High-Throughput and Structural Biology Applications

The highly infectious disease COVID-19 caused by the Betacoronavirus SARS-CoV-2 poses a severe threat to humanity and demands the redirection of scientific efforts and criteria to organized research projects. The international COVID19-NMR consortium seeks to provide such new approaches by gathering scientific expertise worldwide. In particular, making available viral proteins and RNAs will pave the way to understanding the SARS-CoV-2 molecular components in detail. The research in COVID19-NMR and the resources provided through the consortium are fully disclosed to accelerate access and exploitation. NMR investigations of the viral molecular components are designated to provide the essential basis for further work, including macromolecular interaction studies and high-throughput drug screening. Here, we present the extensive catalog of a holistic SARS-CoV-2 protein preparation approach based on the consortium’s collective efforts. We provide protocols for the large-scale production of more than 80% of all SARS-CoV-2 proteins or essential parts of them. Several of the proteins were produced in more than one laboratory, demonstrating the high interoperability between NMR groups worldwide. For the majority of proteins, we can produce isotope-labeled samples of HSQC-grade. Together with several NMR chemical shift assignments made publicly available on covid19-nmr.com, we here provide highly valuable resources for the production of SARS-CoV-2 proteins in isotope-labeled form

The experience of being admitted to a psychiatric clinic Part 1: development of a questionnaire (QAE-P)

Hintergrund Das Ziel der vorliegenden Untersuchung war die Entwicklung eines Fragebogens zur Erfassung der subjektiven Wahrnehmung und Bewertung der Aufnahme in eine psychiatrische Klinik (FEA-P). Material und Methoden Ausgehend von der Literatur und einer systematischen qualitativen Pilotstudie wurde ein 126 Items umfassender Fragebogen entwickelt und 708 Patienten in 6 Kliniken für Psychiatrie und Psychotherapie vorgelegt. Die Daten wurden an einer randomisierten Teilstichprobe hypothesengenerierend einer exploratorischen Faktorenanalyse (EFA) unterzogen und die Itemanzahl in einer Itemanalyse weiter reduziert. Die resultierende Skalenaufteilung wurde mittels konfirmatorischer Faktorenanalyse (KFA) an der 2. Teilstichprobe validiert. Ergebnisse Aus EFA und Itemanalyse resultierten 33 Items auf 7 Skalen: 1. hilfreich-positiv erlebte Beziehung zu den (Pflege-)Mitarbeitern, 2. (ärztliche) Aufklärung, Behandlungsplan und Einbeziehung der Patienten, 3. räumliche Bedingungen, 4. Kritik an Ärzten und Mitarbeitern, 5. negative Wahrnehmungen von Mitpatienten, 6. Umgang mit Stationsregeln, 7. Stationsatmosphäre. Die Plausibilität dieser Skalenstruktur wird durch die Ergebnisse der KFA gestützt. Schlussfolgerungen Der FEA-P erfüllt die Kriterien der klassischen Testtheorie, bildet ein breites Spektrum von Dimensionen des Erlebens der Aufnahme in eine psychiatrische Klinik ab und ist mit 33 Items praktikabel einsetzbar.Background The aim of the present study was to develop a questionnaire to assess the perception and evaluation of admission to a psychiatric hospital from a patient’s perspective (QAE-P). Material and methods Based on existing literature and a preparatory pilot study, a questionnaire consisting of 126 items was developed, and 708 inpatients based in 6 psychiatry and psychotherapy clinics were asked to answer the items. The resulting data were split into two data sets. In the first subset, exploratory factor analysis was used to help determine the number of scales and provide the basis for item reduction. The resulting questionnaire was validated by means of confirmatory factor analyses (CFA) in the second data subset. Results The resulting questionnaire comprises 33 items in 7 scales, which assess: (1) helpful, positive relations with staff members; (2) offering of medical explanations to patients and their involvement in treatment planning; (3) evaluation of rooms and clinical environment; (4) dissatisfaction with doctors and staff members; (5) evaluation of handling of ward rules by staff; (6) perception of ward atmosphere; and (7) negative perception of other inpatients. The plausibility of this factorial structure was supported by the results of the CFA. Conclusions The QAE-P is a short and feasible questionnaire that meets the criteria of classic test theory and assesses different dimensions of the patient’s experience of admission to a psychiatric hospital

Exploring the pH dependence of an improved PETase

International audienceEnzymatic recycling of plastic and especially of polyethylene terephthalate (PET) has shown great potential to reduce its negative impact on our society. PET hydrolases (PETases) have been optimized using rational design and machine learning, but the mechanistic details of the PET depolymerization process remain unclear. Belonging to the carboxylic-ester hydrolase family with a canonical Ser-His-Asp catalytic triad, their observed alkaline pH optimum is generally thought to be related to the protonation state of the catalytic His. Here, we explore this aspect in the context of LCCICCG, an optimized PETase, derived from the Leaf-branch Compost Cutinase (LCC) enzyme. We use NMR to identify the dominant tautomeric structure of the six histidines. Five show surprisingly low pKa values below 4.0 while the catalytic H242 in the active enzyme displays a pKa value that varies from 4.9 to 4.7 when temperatures increase from 30°C to 50°C. Whereas the hydrolytic activity of the enzyme towards a soluble substrate can be modeled by the corresponding protonation/deprotonation curve, an important discrepancy is found when the substrate is the solid plastic. This opens the way to further mechanistic understanding of the PETase activity, and underscores the importance of studying the enzyme at the liquid/solid interfac

Extract from Rumex acetosa L. for Prophylaxis of Periodontitis: Inhibition of Bacterial In Vitro Adhesion and of Gingipains of Porphyromonas gingivalis by Epicatechin-3-O-(4β→8)-Epicatechin-3-O-Gallate (Procyanidin-B2-Di-Gallate)

Background: The aerial parts of Rumex acetosa L. have been used in traditional European medicine for inflammatory diseases of the mouth epithelial tissue. The following study aimed to investigate the influence of a proanthocyanidin-enriched extract from R. acetosa extract against the adhesion of Porphyromonas gingivalis (P. gingivalis), a pathogen strongly involved in chronic and aggressive periodontitis. A further goal was to define the bioactive lead structures responsible for a potential antiadhesive activity and to characterize the underlying molecular mechanisms of the antiadhesive effects. Methodology: An extract of R. acetosa (RA1) with a defined mixture of flavan-3-ols, oligomeric proanthocyanidins and flavonoids, was used. Its impact on P. gingivalis adhesion to KB cells was studied by flow cytometry, confocal laser scanning microscopy and in situ adhesion assay using murine buccal tissue. RA1 and its compounds 1 to 15 were further investigated for additional effects on gingipain activity, hemagglutination and gene expression by RT-PCR. Principal Findings: RA1 (5 to 15 μg/mL) reduced P. gingivalis adhesion in a dose-dependent manner to about 90%. Galloylated proanthocyanidins were confirmed to be responsible for this antiadhesive effect with epicatechin-3-O-gallate-(4β,8)-epicatech​in-3’-O-gallate(syn. procyanidin B2-di-gallate) being the lead compound. Ungalloylated flavan-3-ols and oligomeric proanthocyanidins were inactive. RA1 and the galloylated proanthocyanidins strongly interact with the bacterial virulence factor Arg-gingipain, while the corresponding Lys-gingipain was hardly influenced. RA1 inhibited also hemagglutination. In silico docking studies indicated that epicatechin-3-O-gallate-(4β,8)-epicatech​in-3’-O-gallateinteracts with the active side of Arg-gingipain and hemaglutinin from P. gingivalis; the galloylation of the molecule seems to be responsible for fixation of the ligand to the protein. In conclusion, the proanthocyanidin-enriched extract RA1 and its main active constituent procyanidin B2-di-gallate protect cells from P. gingivalis infection by inhibiting bacterial adhesion to the host cell. RA1 and procyanidin B2-di-gallate appear to be promising candidates for future cytoprotective preparations for oral mouth care products

UHPLC of RA1 (1 mg/mL).

<p><b>7</b> epicatechin-(4β→8)-epicatechin, <b>14</b> epicatechin-(4β-→8)-epicatechin(4β→8,2β→O→7)-epicatechin, <b>5</b> epicatechin-3-O-gallate, <b>15</b> quercetin-3-O-glucuronide, <b>8</b> epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate, <b>IS</b> internal standard epigallocatechin-3-O-gallate.</p