"... auch auf das Werkzeug kommt es an" – Eine technikhistorische und techniktheoretische Annäherungen an den Werkzeugbegriff in der Medienpädagogik

Im Rahmen einer allgemeinpädagogischen und mediendidaktischen Betrachtung tradierter und aktueller Unterrichtsmedien sowie einer technikhistorischen und techniktheoretischen Annäherung an Potentiale digitaler Lehr- und Lernmedien wird im Beitrag eine begriffliche Differenzierung zwischen Unterrichts- und Bildungsmedien und didaktischen Werkzeugen vorgeschlagen. Die theoretisch-konzeptionelle Analyse zeigt, dass der Werkzeugbegriff den situativen Kontext der jeweiligen Nutzung sowie die Nutzenden in den Vordergrund rückt. Da moderne digitale Werkzeuge mediale Elemente, Codes und Repräsentationen konvergieren und sich durch Adaptivität auszeichnen, eröffnen sie neue gestalterische Zugänge und Möglichkeitsräume. Innerhalb dieser können Lehr- und Lernwerkzeuge auch außerhalb technischer Disziplinen – nämlich an pädagogischen und didaktischen Fragen orientiert – kontextbezogen und praxisnah entwickelt werden. Als disziplinäre Orte einer solchen übergreifenden Entwicklungspartnerschaft zwischen Pädagogik und Technik werden die Disziplinen der Medienpädagogik und der Bildungsinformatik vorgeschlagen. Diese interdisziplinäre Schnittmenge wird mit innovativen Ansätzen verbunden, die die Methodendiskussion der Medienpädagogik bereichern und die Bildungsinformatik begründen soll. (Autor

Not all GKK τ\tau-matrices are stable

Hermitian positive definite, totally positive, and nonsingular M-matrices enjoy many common properties, in particular: (A) positivity of all principal minors, (B) weak sign symmetry, (C) eigenvalue monotonicity, (D) positive stability. The class of GKK matrices is defined by properties (A) and (B), whereas the class of nonsingular $\tau$-matrices by (A) and (C). It was conjectured that: (A), (B) implies (D) [D. Carlson, J. Res. Nat. Bur. Standards Sect. B 78 (1974) 1-2], (A), (C) implies (D) [G.M. Engel and H. Schneider, Linear and Multilinear Algebra 4 (1976) 155-176], (A), (B) implies a property stronger than (D) [R. Varga, Numerical Methods in Linear Algebra, 1978, pp. 5-15], (A), (B), (C) implies (D) [D. Hershkowitz, Linear Algebra Appl. 171 (1992) 161-186]. We describe a class of unstable GKK $\tau$-matrices, thus disproving all four conjectures.Comment: 7 page

Incidence of grapevine leafroll associated viruses -1, -2, and -3 in Mendoza vineyards

Indexación: ScieloViticulture is important in Argentina's economy, especially in the province of Mendoza, which is responsible for more than 75% of the crop cultivated area. In this work, we evaluated the incidence of Grapevine leafroll-associated viruses (GLRaV) -1, -2, and -3 in Vitis vinifera clones of cultivars Cabernet Sauvignon, Cabernet Franc, and Sauvignon Blanc, planted in different zones of Mendoza. The selected clones were previously reported as putatively infected by GLRaV-2. All selected samples were analyzed by DAS-ELISA for GLRaV-1,-2 and -3. GLRaV-2 was the only virus identified in all the analyzed clones. The overall infection rates were 0.6%, 18.8% and 1.2 % for GLRaV-1, 2 and 3 respectively. For the clone Cabernet Sauvignon 337, the infection rate was very high (68.3%).http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1982-56762010000600007&nrm=is

Abschlussbericht Projekt fraLine. Oktober 2001 bis August 2014 unter besonderer Berücksichtigung der 4. Projektlaufzeit September 2011 bis August 2014

Das Kooperationsprojekt fraLine endete nach über zwölf Jahren im August 2014. Ein außergewöhnliches Projekt wurde damit abgeschlossen. Der Rückblick auf über zwölf Jahre partnerschaftliche IT- und Medienentwicklung gemeinsam mit den 156 Frankfurter Schulen und dem Stadtschulamt zeigt: Der zunehmende gesellschaftliche Wunsch, mit Computer und Internet auch in Schule und Unterricht zu arbeiten, verlangte eine zuverlässige und sichere technische Medieninfrastruktur sowie ein Betreuungskonzept, das sich an den Bedarfen der Schulen orientiert. Hierzu galt es, tragfähige Konzepte sowie unterstützende Tools zu entwickeln. Mit der technischen Weiterentwicklung digitaler Medien und den damit einhergehenden neuen Einsatzszenarien im Unterricht änderten sich auch die Anforderungen an Technik und Unterstützungssysteme: Benötigt wurden nun übergeordnete und nachhaltige, aber auch effiziente Konzepte für die Administration und Benutzerverwaltung der Geräte sowie für deren Einsatz im Rahmen der Schulorganisation und für den lehrunterstützenden und lernförderlichen Einsatz im Unterricht. (Autor

Open problems on GKK tau-matrices

We propose several open problems on GKK tau-matrices raised by examples showing that some such matrices are unstableComment: To appear in Linear Algebra and its Applications (LAA

Crystal and Molecular Structure of Chelidonine

The crystal and molecular structure of benzophenantridine alkaloid chelidonine, C20H19N05 CM = 353.37) was solved by direct methods and refined by the least-squares technique to a conventional R index of 0.117 for 1888 unique reflections. The crystals are monoclinic, space group P21. Both, B and C rings have half chair conformation and are in cis junction. The N-methyl and C14-hydroxyl groups are in equatorial and axial positions, respectively. The OH-group forms intramolecular hydrogen bond with N atom. Conformation of the molecule is quite different from that found in chelidonine-p-brombenzoateCBB)

Incidence of Grapevine Leafroll Associated Viruses -1, -2, and -3 in Mendoza vineyards

Viticulture is important in Argentina's economy, especially in the province of Mendoza, which is responsible for more than 75% of the crop cultivated area. In this work, we evaluated the incidence of Grapevine leafroll-associated viruses (GLRaV) -1, -2, and -3 in Vitis vinifera clones of cultivars Cabernet Sauvignon, Cabernet Franc, and Sauvignon Blanc, planted in different zones of Mendoza. The selected clones were previously reported as putatively infected by GLRaV-2. All selected samples were analyzed by DAS-ELISA for GLRaV-1,-2 and -3. GLRaV-2 was the only virus identified in all the analyzed clones. The overall infection rates were 0.6%, 18.8% and 1.2 % for GLRaV-1, 2 and 3 respectively. For the clone Cabernet Sauvignon 337, the infection rate was very high (68.3%).A viticultura é importante para a economia da Argentina, especialmente na província de Mendoza, que abrange mais de 75% da área cultivada do país. Neste trabalho, nós avaliamos a incidência de Grapevine leafroll associated virus (GLRaV) -1, -2 e -3 em clones de Vitis vinifera das cultivares Cabernet Sauvignon, Cabernet Franc e Sauvignon Blanc, cultivadas em diferentes zonas de Mendoza. Os clones selecionados foram previamente relatados como provavelmente infectados por GLRaV-2. Todas as amostras selecionadas foram analisadas por DAS-ELISA para GLRaV-1, -2 e -3. GLRaV-2 foi o único vírus identificado em todos os clones analisados. As incidëncias das infecçoes globais foram 0,6%, 18,8% e 1,2% para GLRaV-1, 2 e 3, respectivamente. No Cabernet Sauvignon clone 337 a incidëncia da infecção foi muito elevado (68,3%)Fil: Lanza Volpe, Melisa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Gomez Talquenca, Gonzalo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Engel, Esteban A. Fundación Ciencia para la Vida; Chile. Universidad Andrés Bello. Facultad de Ciencias de la Salud; ChileFil: Gracia, Olga. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentin

The neurovirulence and neuroinvasiveness of chimeric tick-borne encephalitis/dengue virus can be attenuated by introducing defined mutations into the envelope and NS5 protein genes and the 3′ non-coding region of the genome

AbstractTick-borne encephalitis (TBE) is a severe disease affecting thousands of people throughout Eurasia. Despite the use of formalin-inactivated vaccines in endemic areas, an increasing incidence of TBE emphasizes the need for an alternative vaccine that will induce a more durable immunity against TBE virus (TBEV). The chimeric attenuated virus vaccine candidate containing the structural protein genes of TBEV on a dengue virus genetic background (TBEV/DEN4) retains a high level of neurovirulence in both mice and monkeys. Therefore, attenuating mutations were introduced into the envelope (E315) and NS5 (NS5654,655) proteins, and into the 3′ non-coding region (Δ30) of TBEV/DEN4. The variant that contained all three mutations (vΔ30/E315/NS5654,655) was significantly attenuated for neuroinvasiveness and neurovirulence and displayed a reduced level of replication and virus-induced histopathology in the brains of mice. The high level of safety in the central nervous system indicates that vΔ30/E315/NS5654,655 should be further evaluated as a TBEV vaccine

Impact of COVID-19 pandemic on patients and health professionals of a radiation oncology department at a Spanish tertiary hospital

Background: The sanitary emergency created by the COVID-19 pandemic forced us to take exceptional measures that affect decision-making and administration of treatments with radiotherapy. The aim of the study was to analyze the impact of the COVID-19 pandemic on patients and professionals in a radiation oncology department. Materials and methods: We implement a plan with the objectives of maintaining radiotherapy treatment in those patients who need it and, at the same time, reducing the risk of spreading the virus to staff and patients. This plan included measures aimed at limiting the patient's stay in hospital, selecting those patients in whom radiotherapy cannot be delayed and protecting against infection through the use of physical protective measures. Results: Between March 16 and May 31, 2020, 360 patients received radiotherapy in our department. In 14 patients (4.7%) the start of treatment was delayed by an average of 28 days. Four patients had a positive COVID-19 polymerase chain reaction (PCR) (6.6% and 1.1% of tested and all patients, respectively). Among the professionals, two PCRs were positive (16.6% and 4% of tested and all individuals, respectively). In the serology analysis 4 out of 50 department members were IgG positive (8%). Conclusions: Despite the fact that our department is located in a region with a high incidence of COVID-19 infection, the impact of the pandemic on our patients and staff has been moderate. The implementation of measures against infection and an adequate selection of patients for treatment allows radiation oncology departments to maintain clinical activity