105 research outputs found

    Digital Teaching and Learning in the Corona Semester from the Perspective of Students: Consequences for an Agile Quality Development

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    Die pandemiebedingte, kurzfristige Umstellung der Hochschullehre auf ausschliesslich digitale Veranstaltungsangebote stellte Lehrende und Studierende im Frühjahr 2020 vor grosse Herausforderungen. Unter enormem Zeitdruck mussten bewährte Präsenzlehrformate transformiert und für Lehrende wie Studierende organisationale Unterstützungssysteme etabliert werden. Dieser forcierte Digitalisierungsprozess beinhaltet für hiesige Hochschulen die Chance, die Weiterentwicklung der Lehre agil und evidenzbasiert voranzutreiben und dabei nicht zuletzt auch die Herausforderungen und Grenzen digitalen Lernens zu identifizieren. Nachhaltige Digitalisierungsstrategien sollten ganzheitlich und mehrperspektivisch sein, hier bietet insbesondere der Einbezug der Perspektive von Studierenden wichtige Einsichten für den Digitalisierungsprozess und die Qualitätsentwicklung der Hochschullehre. Diesem Beitrag liegen die Fragen zugrunde, wie Studierende die Rahmenbedingungen, Qualität und Effekte der digitalen Hochschullehre im ersten Corona-Semester 2020 bewerten und mit welchen spezifischen Herausforderungen sie sich konfrontiert sehen. Erkenntnisse dazu wurden an der Universität Stuttgart im Rahmen einer Fragebogenerhebung in drei Wellen gewonnen. Es zeigt sich etwa, dass die Strukturierung der Arbeit zuhause vielen Studierenden schwerfällt und die gefühlte Arbeitsbelastung gestiegen ist. Besonders Bachelorstudierende wünschen sich mehr Unterstützung bei der Vorbereitung auf Prüfungen und der Koordination von Lerngruppen. Neben der Ableitung von konkreten Optimierungsempfehlungen stehen insbesondere die Konsequenzen im Fokus, die sich für die strategische Qualitätsentwicklung der Hochschullehre und den weiteren Digitalisierungsprozess ergeben.The pandemic-related, short-term conversion of university teaching to the digital confronted lecturers and students with major challenges in spring 2020. Under enormous time pressure, proven teaching formats had to be transformed and organizational support systems had to be established for both teachers and students. This accelerated digitization process offers universities the opportunity to drive forward the further development of teaching in an agile and evidence-based manner and to identify the challenges and limitations of digital learning. Sustainable digitization strategies should be holistic and multi-perspective, especially including the perspective of students offers important insights for the digitization process and the quality development of university teaching. This paper is based on the questions of how students evaluate the conditions, quality and effects of the digital teaching in the first Corona Semester 2020 and what specific challenges they face. Findings were obtained at the University of Stuttgart as part of a questionnaire survey in three waves. Many students find it difficult to structure their work at home and their perceived workload has increased. Especially bachelor students need more support in preparing for exams and coordinating learning groups. Consequences for the strategic quality development of university teaching and the digitization process are taken in view

    Drosophila Serpin-28D regulates hemolymph phenoloxidase activity and adult pigmentation

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    In insects the enzyme phenoloxidase (PO) catalyzes melanin deposition at the wound site and around parasitoid eggs. Its proenzyme prophenoloxidase (proPO) is proteolytically cleaved to active phenoloxidase by a cascade consisting of serine proteases and inhibited by serpins. The Drosophila genome encodes 29 serpins, of which only two, Serpin-27A (Spn27A) and Necrotic, have been analyzed in detail. Using a genetic approach, we demonstrate that the so far uncharacterized Serpin-28D (Spn28D, CG7219) regulates the proPO cascade in both hemolymph and tracheal compartments. spn28D is the serpin gene most strongly induced upon injury. Inactivation of spn28D causes pupal lethality and a deregulated developmental PO activation leading to extensive melanization of tissues in contact with air and pigmentation defects of the adult cuticle. Our data also show that Spn28D regulates hemolymph PO activity in both larvae and adults at a different level than Spn27A. Our data support a model in which Spn28D confines PO availability by controlling its initial release, while Spn27A is rather limiting the melanization reaction to the wound site. This study further highlights the complexity of the proPO cascade that can be differentially regulated in different tissues during development

    Comparison of embedded and added motor imagery training in patients after stroke: Results of a randomised controlled pilot trial

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    Copyright @ 2012 Schuster et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Motor imagery (MI) when combined with physiotherapy can offer functional benefits after stroke. Two MI integration strategies exist: added and embedded MI. Both approaches were compared when learning a complex motor task (MT): ‘Going down, laying on the floor, and getting up again’. Methods: Outpatients after first stroke participated in a single-blinded, randomised controlled trial with MI embedded into physiotherapy (EG1), MI added to physiotherapy (EG2), and a control group (CG). All groups participated in six physiotherapy sessions. Primary study outcome was time (sec) to perform the motor task at pre and post-intervention. Secondary outcomes: level of help needed, stages of MT-completion, independence, balance, fear of falling (FOF), MI ability. Data were collected four times: twice during one week baseline phase (BL, T0), following the two week intervention (T1), after a two week follow-up (FU). Analysis of variance was performed. Results: Thirty nine outpatients were included (12 females, age: 63.4 ± 10 years; time since stroke: 3.5 ± 2 years; 29 with an ischemic event). All were able to complete the motor task using the standardised 7-step procedure and reduced FOF at T0, T1, and FU. Times to perform the MT at baseline were 44.2 ± 22s, 64.6 ± 50s, and 118.3 ± 93s for EG1 (N = 13), EG2 (N = 12), and CG (N = 14). All groups showed significant improvement in time to complete the MT (p < 0.001) and degree of help needed to perform the task: minimal assistance to supervision (CG) and independent performance (EG1+2). No between group differences were found. Only EG1 demonstrated changes in MI ability over time with the visual indicator increasing from T0 to T1 and decreasing from T1 to FU. The kinaesthetic indicator increased from T1 to FU. Patients indicated to value the MI training and continued using MI for other difficult-to-perform tasks. Conclusions: Embedded or added MI training combined with physiotherapy seem to be feasible and benefi-cial to learn the MT with emphasis on getting up independently. Based on their baseline level CG had the highest potential to improve outcomes. A patient study with 35 patients per group could give a conclusive answer of a superior MI integration strategy.The research project was partially funded by the Gottfried und Julia Bangerter-Rhyner Foundation

    The Toll immune-regulated Drosophila protein Fondue is involved in hemolymph clotting and puparium formation

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    Clotting is critical in limiting hemolymph loss and initiating wound healing in insects as in vertebrates. It is also an important immune defense, quickly forming a secondary barrier to infection, immobilizing bacteria and thereby promoting their killing. However, hemolymph clotting is one of the least understood immune responses in insects. Here, we characterize fondue (fon; CG15825), an immune-responsive gene of Drosophila melanogaster that encodes an abundant hemolymph protein containing multiple repeat blocks. After knockdown of fon by RNAi, bead aggregation activity of larval hemolymph is strongly reduced, and wound closure is affected. fon is thus the second Drosophila gene after hemolectin (hml), for which a knockdown causes a clotting phenotype. In contrast to hml-RNAi larvae, clot fibers are still observed in samples from fon-RNAi larvae. However, clot fibers from fon-RNAi larvae are more ductile and longer than in wt hemolymph samples, indicating that Fondue might be involved in cross-linking of fiber proteins. In addition, fon-RNAi larvae exhibit melanotic tumors and constitutive expression of the antifungal peptide gene Drosomycin (Drs), while fon-RNAi pupae display an aberrant pupal phenotype. Altogether, our studies indicate that Fondue is a major hemolymph protein required for efficient clotting in Drosophila

    Comparison of embedded and added motor imagery training in patients after stroke: Study protocol of a randomised controlled pilot trial using a mixed methods approach

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    Copyright @ 2009 Schuster et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Two different approaches have been adopted when applying motor imagery (MI) to stroke patients. MI can be conducted either added to conventional physiotherapy or integrated within therapy sessions. The proposed study aims to compare the efficacy of embedded MI to an added MI intervention. Evidence from pilot studies reported in the literature suggests that both approaches can improve performance of a complex motor skill involving whole body movements, however, it remains to be demonstrated, which is the more effective one.Methods/Design: A single blinded, randomised controlled trial (RCT) with a pre-post intervention design will be carried out. The study design includes two experimental groups and a control group (CG). Both experimental groups (EG1, EG2) will receive physical practice of a clinical relevant motor task ('Going down, laying on the floor, and getting up again') over a two week intervention period: EG1 with embedded MI training, EG2 with MI training added after physiotherapy. The CG will receive standard physiotherapy intervention and an additional control intervention not related to MI.The primary study outcome is the time difference to perform the task from pre to post-intervention. Secondary outcomes include level of help needed, stages of motor task completion, degree of motor impairment, balance ability, fear of falling measure, motivation score, and motor imagery ability score. Four data collection points are proposed: twice during baseline phase, once following the intervention period, and once after a two week follow up. A nested qualitative part should add an important insight into patients' experience and attitudes towards MI. Semi-structured interviews of six to ten patients, who participate in the RCT, will be conducted to investigate patients' previous experience with MI and their expectations towards the MI intervention in the study. Patients will be interviewed prior and after the intervention period.Discussion: Results will determine whether embedded MI is superior to added MI. Findings of the semi-structured interviews will help to integrate patient's expectations of MI interventions in the design of research studies to improve practical applicability using MI as an adjunct therapy technique

    Pathogen Entrapment by Transglutaminase—A Conserved Early Innate Immune Mechanism

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    Clotting systems are required in almost all animals to prevent loss of body fluids after injury. Here, we show that despite the risks associated with its systemic activation, clotting is a hitherto little appreciated branch of the immune system. We compared clotting of human blood and insect hemolymph to study the best-conserved component of clotting systems, namely the Drosophila enzyme transglutaminase and its vertebrate homologue Factor XIIIa. Using labelled artificial substrates we observe that transglutaminase activity from both Drosophila hemolymph and human blood accumulates on microbial surfaces, leading to their sequestration into the clot. Using both a human and a natural insect pathogen we provide functional proof for an immune function for transglutaminase (TG). Drosophila larvae with reduced TG levels show increased mortality after septic injury. The same larvae are also more susceptible to a natural infection involving entomopathogenic nematodes and their symbiotic bacteria while neither phagocytosis, phenoloxidase or—as previously shown—the Toll or imd pathway contribute to immunity. These results firmly establish the hemolymph/blood clot as an important effector of early innate immunity, which helps to prevent septic infections. These findings will help to guide further strategies to reduce the damaging effects of clotting and enhance its beneficial contribution to immune reactions

    Cellular and Genetic Analysis of Wound Healing in Drosophila Larvae

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    To establish a genetic system to study postembryonic wound healing, we characterized epidermal wound healing in Drosophila larvae. Following puncture wounding, larvae begin to bleed but within an hour a plug forms in the wound gap. Over the next couple of hours the outer part of the plug melanizes to form a scab, and epidermal cells surrounding the plug orient toward it and then fuse to form a syncytium. Subsequently, more-peripheral cells orient toward and fuse with the central syncytium. During this time, the Jun N-terminal kinase (JNK) pathway is activated in a gradient emanating out from the wound, and the epidermal cells spread along or through the wound plug to reestablish a continuous epithelium and its basal lamina and apical cuticle lining. Inactivation of the JNK pathway inhibits epidermal spreading and reepithelialization but does not affect scab formation or other wound healing responses. Conversely, mutations that block scab formation, and a scabless wounding procedure, provide evidence that the scab stabilizes the wound site but is not required to initiate other wound responses. However, in the absence of a scab, the JNK pathway is hyperinduced, reepithelialization initiates but is not always completed, and a chronic wound ensues. The results demonstrate that the cellular responses of wound healing are under separate genetic control, and that the responses are coordinated by multiple signals emanating from the wound site, including a negative feedback signal between scab formation and the JNK pathway. Cell biological and molecular parallels to vertebrate wound healing lead us to speculate that wound healing is an ancient response that has diversified during evolution

    Protein Crosslinking by Transglutaminase Controls Cuticle Morphogenesis in Drosophila

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    Transglutaminase (TG) plays important and diverse roles in mammals, such as blood coagulation and formation of the skin barrier, by catalyzing protein crosslinking. In invertebrates, TG is known to be involved in immobilization of invading pathogens at sites of injury. Here we demonstrate that Drosophila TG is an important enzyme for cuticle morphogenesis. Although TG activity was undetectable before the second instar larval stage, it dramatically increased in the third instar larval stage. RNA interference (RNAi) of the TG gene caused a pupal semi-lethal phenotype and abnormal morphology. Furthermore, TG-RNAi flies showed a significantly shorter life span than their counterparts, and approximately 90% of flies died within 30 days after eclosion. Stage-specific TG-RNAi before the third instar larval stage resulted in cuticle abnormality, but the TG-RNAi after the late pupal stage did not, indicating that TG plays a key role at or before the early pupal stage. Immediately following eclosion, acid-extractable protein from wild-type wings was nearly all converted to non-extractable protein due to wing maturation, whereas several proteins remained acid-extractable in the mature wings of TG-RNAi flies. We identified four proteins—two cuticular chitin-binding proteins, larval serum protein 2, and a putative C-type lectin—as TG substrates. RNAi of their corresponding genes caused a lethal phenotype or cuticle abnormality. Our results indicate that TG-dependent protein crosslinking in Drosophila plays a key role in cuticle morphogenesis and sclerotization

    Identification of unannotated exons of low abundance transcripts in Drosophila melanogaster and cloning of a new serine protease gene upregulated upon injury

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    <p>Abstract</p> <p>Background</p> <p>The sequencing of the <it>D.melanogaster </it>genome revealed an unexpected small number of genes (~ 14,000) indicating that mechanisms acting on generation of transcript diversity must have played a major role in the evolution of complex metazoans. Among the most extensively used mechanisms that accounts for this diversity is alternative splicing. It is estimated that over 40% of <it>Drosophila </it>protein-coding genes contain one or more alternative exons. A recent transcription map of the <it>Drosophila </it>embryogenesis indicates that 30% of the transcribed regions are unannotated, and that 1/3 of this is estimated as missed or alternative exons of previously characterized protein-coding genes. Therefore, the identification of the variety of expressed transcripts depends on experimental data for its final validation and is continuously being performed using different approaches. We applied the Open Reading Frame Expressed Sequence Tags (ORESTES) methodology, which is capable of generating cDNA data from the central portion of rare transcripts, in order to investigate the presence of hitherto unnanotated regions of <it>Drosophila </it>transcriptome.</p> <p>Results</p> <p>Bioinformatic analysis of 1,303 <it>Drosophila </it>ORESTES clusters identified 68 sequences derived from unannotated regions in the current <it>Drosophila </it>genome version (4.3). Of these, a set of 38 was analysed by polyA<sup>+ </sup>northern blot hybridization, validating 17 (50%) new exons of low abundance transcripts. For one of these ESTs, we obtained the cDNA encompassing the complete coding sequence of a new serine protease, named SP212. The <it>SP212 </it>gene is part of a serine protease gene cluster located in the chromosome region 88A12-B1. This cluster includes the predicted genes CG9631, CG9649 and CG31326, which were previously identified as up-regulated after immune challenges in genomic-scale microarray analysis. In agreement with the proposal that this <it>locus </it>is co-regulated in response to microorganisms infection, we show here that SP212 is also up-regulated upon injury.</p> <p>Conclusion</p> <p>Using the ORESTES methodology we identified 17 novel exons from low abundance <it>Drosophila </it>transcripts, and through a PCR approach the complete CDS of one of these transcripts was defined. Our results show that the computational identification and manual inspection are not sufficient to annotate a genome in the absence of experimentally derived data.</p
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