115 research outputs found

    Investigation of the marine compound spongistatin 1 links the inhibition of PKCĪ± translocation to nonmitotic effects of tubulin antagonism in angiogenesis

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    The aims of the study were to meet the demand of new tubulin antagonists with fewer side effects by characterizing the antiangiogenic properties of the experimental compound spongistatin 1, and to elucidate nonmitotic mechanisms by which tubulin antagonists inhibit angiogenesis. Although tubulin-inhibiting drugs and their antiangiogenic properties have been investigated for a long time, surprisingly little is known about their underlying mechanisms of action. Antiangiogenic effects of spongistatin 1 were investigated in endothelial cells in vitro, including functional cell-based assays, live-cell imaging, and a kinome array, and in the mouse cornea pocket assay in vivo. Spongistatin 1 inhibited angiogenesis at nanomolar concentrations (IC50: cytotoxicity>50 nM, proliferation 100 pM, migration 1.0 nM, tube formation 1.0 nM, chemotaxis 1.0 nM, aortic ring sprouting 500 pM, neovascularization in vivo 10 Ī¼g/kg). Further, a kinome array and validating data showed that spongistatin 1 inhibits the phosphorylation activity of protein kinase CĪ± (PKCĪ±), an essential kinase in angiogenesis, and its translocation to the membrane. Thus, we conclude that PKCĪ± might be an important target for the antiangiogenic effects of tubulin antagonism. In addition, the data from the kinase array suggest that different tubulin antagonists might have individual intracellular actions.ā€”Rothmeier, A. S., Ischenko, I., Joore, J., Garczarczyk, D., FuĀØrst, R., Bruns, C. J., Vollmar, A. M., Zahler, S. Investigation of the marine compound spongistatin 1 links the inhibition of PKCĪ± translocation to nonmitotic effects of tubulin antagonism in angiogenesis

    Crop cultural and chemical methods to control grey mould on grapes

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    The efficiency of crop cultural (leaf removal) as well as of chemical methods (plant growth regulator, botryticide) to control grey mould caused by Botrytis cinerea was investigated in two seasons (2008 and 2009) on the varieties 'Pinot blanc' and 'Pinot gris' in the Moselle valley (Luxembourg). The application of the plant growth regulator RegalisĀ® (a.i. prohexadione-Ca) led to a considerably more flexible cluster structure and a slight decrease of grey mould disease severity. The reduction of bunch rot infestation was of the same level than obtained by a single application of a botryticide (a.i. fenhexamid) before berries touching. Leaf removal reduced the cluster density slightly and proved to be more efficient against B. cinerea than the chemical treatments (reduction of grey mould disease severity of 57 % on average). Thus, leaf removal in the cluster-zone shortly after bloom can be recommended as an important tool in integrated as well as in organic bunch rot protection strategies. The best loosening effect on the cluster structure as well as the best B. cinerea reduction efficiency (75 % on average) was achieved when combining leaf removal and RegalisĀ® application. The combination of leaf removal and botryticide application showed comparable results. Simulation of the B. cinerea epidemiology demonstrated that all treatments tested might allow for a longer maturation time due to lower infestation. The longest potential harvest delay until reaching an assumed threshold of 5 % disease severity was achieved by combining leaf removal and application of RegalisĀ® or a botryticide (on average 11.6 or 9.9 days, respectively). The here presented strategies can thus be recommended to maximize wine quality in two ways ā€“ through a reduction of fungal contamination and/or an improvement of grape maturity.

    XAS signatures of Am(III) adsorbed onto magnetite and maghemite

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    Trivalent americium was adsorbed on magnetite and maghemite under similar chemical conditions and the local environment probed by EXAFS spectroscopy. In both samples, partially hydrated Am(III) binds the surface but slightly different surface complexes were identified. On Fe3O4, Am(III) forms monomeric tridentate surface complexes similar to that reported for Pu(III) at the (111) surface. In contrast, the lower number of detected Fe atoms may suggest that Am(III) forms monomeric bidentate surface complexes on Ī³-Fe2O3. Alternatively, the lower Fe coordination number can also be due to the presence of vacancies in maghemite. XPS data imply very similar binding environments for Am at both Fe oxide surfaces

    TVB-EduPack: An interactive learning and scripting platform for The Virtual Brain

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    The Virtual Brain (TVB; thevirtualbrain.org) is a neuroinformatics platform for full brain network simulation based on individual anatomical connectivity data. The framework addresses clinical and neuroscientific questions by simulating multi-scale neural dynamics that range from local population activity to large-scale brain function and related macroscopic signals like electroencephalography and functional magnetic resonance imaging. TVB is equipped with a graphical and a command-line interface to create models that capture the characteristic biological variability to predict the brain activity of individual subjects. To enable researchers from various backgrounds a quick start into TVB and brain network modeling in general, we developed an educational module: TVB-EduPack. EduPack offers two educational functionalities that seamlessly integrate into TVB's graphical user interface (GUI): (i) interactive tutorials introduce GUI elements, guide through the basic mechanics of software usage and develop complex use-case scenarios; animations, videos and textual descriptions transport essential principles of computational neuroscience and brain modeling; (ii) an automatic script generator records model parameters and produces input files for TVB's Python programming interface; thereby, simulation configurations can be exported as scripts that allow flexible customization of the modeling process and self-defined batch- and post-processing applications while benefitting from the full power of the Python language and its toolboxes. This article covers the implementation of TVB-EduPack and its integration into TVB architecture. Like TVB, EduPack is an open source community project that lives from the participation and contribution of its users. TVB-EduPack can be obtained as part of TVB from thevirtualbrain.org

    The significance of trust in the political system and motivation for pupils' learning progress in politics lessons

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    Very little research has been conducted on the contribution of political education to learning progress in Germany. Hence, there is a need for intervention studies measuring performance against the theoretical background of a political competence model. This model comprises three constructs: subject knowledge, motivation and attitudes. According to this model, politics lessons should not only convey knowledge but also arouse subject interest, promote political attitudes and develop problem-solving skills. This study investigates how knowledge acquisition is influenced by intervention using theory-oriented teaching materials on the European Union, intervention using conventional textbooks on the European Union and politics lessons without any reference to the European Union. It further asks how the performance-related self-concept and subject interest in political issues impact political knowledge and whether civic virtue and trust in the system are related to it. The sample comprises 1071 pupils. Theory-oriented politics classes lead to greater growth of pupilsā€™ knowledge than in the control group. As anticipated, this study proves that a positive subject-specific self-concept impacts knowledge. The examination of political attitudes reveals a positive correlation between civic virtue and knowledge. There is no connection between trust in the political system and knowledge

    Konstruktivistische AnsƤtze in der Erwachsenenbildung und Weiterbildung

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    Theoretical approaches in the field of further education and advanced vocational training have to face multifaceted demands: the analysis of knowledge aquisition and knowledge transfer and its instructional support as well as the revealment of the mechanisms which influence further education on an organisational level in companies. This article describes, that herefore especially moderate constructivistic approaches are useful. After an introduction to the philosophical tradition of these approaches and important characteristics of adult learning, two examples of constructivistic models are being described particularly: The theory of situated learning environments and career counseling. Concluding it is shown, that a moderate constructive perspective fulfils important criteria for the theoretic modelling of further education processes.Theoretische AnsƤtze in der Erwachsenen- und insbesondere in der beruflichen Weiterbildung mĆ¼ssen sich vielfƤltigen AnsprĆ¼chen stellen: der Analyse des Wissenserwerbs und Wissenstransfers und seiner instruktionalen UnterstĆ¼tzung ebenso wie der Aufdeckung der Mechanismen, die in den Betrieben auf organisatorischer Ebene die Weiterbildung beeinflussen. In diesem Beitrag wird die Auffassung vertreten, daƟ dafĆ¼r insbesondere liberalisierte konstruktivistische AnsƤtze gut geeignet sind. Nach einer EinfĆ¼hrung in die philosophische Tradition dieser AnsƤtze und wichtiger Merkmale des Lernens im Erwachsenenalter werden zwei Beispiele konstruktivistischer Modelle genauer beschrieben: die Theorie situierter Lernumgebungen und das career counseling. AbschlieƟend wird gezeigt, daƟ eine liberalisierte konstruktivistische Perspektive wichtige Kriterien fĆ¼r die theoretische Modellierung von Weiterbildungsprozessen erfĆ¼llt

    Lipid rafts are essential for release of phosphatidylserine-exposing extracellular vesicles from platelets.

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    Platelets protect the vascular system during damage or inflammation, but platelet activation can result in pathological thrombosis. Activated platelets release a variety of extracellular vesicles (EVs). EVs shed from the plasma membrane often expose phosphatidylserine (PS). These EVs are pro-thrombotic and increased in number in many cardiovascular and metabolic diseases. The mechanisms by which PS-exposing EVs are shed from activated platelets are not well characterised. Cholesterol-rich lipid rafts provide a platform for coordinating signalling through receptors and Ca2+ channels in platelets. We show that cholesterol depletion with methyl-Ī²-cyclodextrin or sequestration with filipin prevented the Ca2+-triggered release of PS-exposing EVs. Although calpain activity was required for release of PS-exposing, calpain-dependent cleavage of talin was not affected by cholesterol depletion. P2Y12 and TPĪ±, receptors for ADP and thromboxane A2, respectively, have been reported to be in platelet lipid rafts. However, the P2Y12 antagonist, AR-C69931MX, or the cyclooxygenase inhibitor, aspirin, had no effect on A23187-induced release of PS-exposing EVs. Together, these data show that lipid rafts are required for release of PS-exposing EVs from platelets.Isaac Newton Trust/ Wellcome Trust ISSF/University of Cambridge Joint Research Grant British Heart Foundation grant SP/15/7/3156

    Neuroinflammatory responses in diabetic retinopathy

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