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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

The role of the JNK/AP-1 pathway in the induction of iNOS and CATs in vascular cells

Zamani, Marzieh January 2013 (has links)
Nitric oxide (NO) is an important biological molecule within the body, which over production of this molecule in response to different stimulations can cause various inflammatory diseases. Over production of this molecule is caused by the induction of the inducible nitric oxide synthase (iNOS) enzyme. This enzyme uses L-arginine as a substrate and therefore the presence and transport of this amino acid into the cells can be a key factor in regulating NO over production. Different signalling mechanisms have been implicated in the regulation of this pathway and one of which involves the Mitogen Activated Protein Kinases (MAPK). This family of proteins respond to inflammatory conditions and may mediate effects induced by inflammatory mediators. Of the MAPKs, the role of the c-Jun-N-terminal kinase (JNK) pathway in the induction of iNOS is still controversial. JNK and its downstream target, the transcription factor Activator Protein-1 (AP-1), have shown contradictory effects on iNOS induction leading to controversies over their role in regulating iNOS expression in different cell systems or with various stimuli. The studies described in this thesis have determined the role of JNK/AP-1 on iNOS expression, NO production, L-arginine uptake and also on the transporters responsible for L-arginine transport into the cells. The studies were carried out in two different cell types: rat aortic smooth muscle cells (RASMCs) and J774 macrophages which are both critically associated with the over production of NO in vascular inflammatory disease states. The first approach was to block the expression of the inducible L-arginine-NO pathway using SP600125 and JNK Inhibitor VIII which are both pharmacological inhibitors of JNK. The results from these studies showed that the pharmacological intervention was without effect in RASMCs, but inhibited iNOS, NO and L-arginine transport in J774 macrophages. In contrast, the molecular approach employed using two dominant negative constructs of AP-1 (TAM-67 and a-Fos) revealed a different profile of effects in RASMCs, where a-Fos caused an induction in iNOS and NO while TAM-67 had an inhibitory effect on iNOS, NO, L-arginine transport and CAT-2B mRNA expression. The latter was unaffected in RASMCs but suppressed in J774 macrophages by SP600125. Examination of JNK isoforms expression showed the presence of JNK1 and 2 in both cell systems. Moreover, stimulation with LPS/IFN- or LPS alone resulted in JNK phosphorylation which did not reveal any difference between smooth muscle cells and macrophages. In contrast, expression and activation of AP-1 subunits revealed differences between the two cell systems. Activation of cells with LPS and IFN- (RASMCs) or LPS alone (J774 macrophages) resulted in changes in the activated status of the different AP-1 subunit which was different for the two cell systems. In both cell types c-Jun, JunD and Fra-1 were increased and in macrophages, FosB activity was also enhanced. Inhibition of JNK with SP600125 caused down-regulation in c-Jun in both cell types. Interestingly this down-regulation was in parallel with increases in the subunits JunB, JunD, c-Fos and Fra-1 in RASMCs or JunB and Fra-1 in J774 macrophages. Since, SP600125 was able to exert inhibitory effects in the latter cell type but not in RASMCs, it is possible that the compensatory up-regulation of certain AP-1 subunits in the smooth muscle cells may compensate for c-Jun inhibition thereby preventing suppression of iNOS expression. This notion clearly needs to be confirmed but it is potentially likely that hetero-dimers formed between JunB, JunD, c-Fos and Fra-1 could sustain gene transcription in the absence of c-Jun. The precise dimer required has not been addressed but unlikely to exclusively involve JunB and Fra-1 as these are up-regulated in macrophages but did not sustain iNOS, NO or induced L-arginine transport in the presence of SP600125. To further support the argument above, the dominant negatives caused varied effects on the activation of the different subunits. a-Fos down-regulated c-Jun, c-Fos, FosB, Fra-1 whereas TAM-67 reduced c-Jun and c-Fos but marginally induced Fra-1 activity. Associated with these changes was an up-regulation of iNOS-NO by a-Fos and inhibition by TAM-67. Taken together, the data proposes a complex mechanism(s) that regulate the expression of the inducible L-arginine-NO pathway in different cell systems and the complexity may reflect diverse intracellular changes that may be different in each cell type and not always be apparent using one experimental approach especially where this is pharmacological. Moreover, these findings strongly suggest exercising caution when interpreting pure pharmacological findings in cell-based systems particularly where these are inconsistent or contradictory.
322

Effects of Wnt and different TLR stimulations on microglia-induced invasion of breast cancer cells

Chuang, Eugenia Han-Ning 04 July 2011 (has links)
No description available.
323

Lifestyle and Biological Risk Factors for Liver Fibrosis in the Miami Adult Studies on HIV (MASH) Cohort: An HIV Infected and HIV/HCV Co-infected Population

Stewart, Tiffanie S. 15 April 2016 (has links)
Liver disease is now a leading cause of non-AIDS related morbidity and mortality in people living with HIV (PLWH). The present study investigated the interplay between adverse lifestyle factors that are prevalent in PLWH, biological mediators of liver pathogenesis, and a non-invasive measure of liver fibrosis (FIB-4 index) in HIV mono- and HIV/HCV co-infected individuals. The results of this investigation in the Miami Adult Studies of HIV (MASH) cohort show that the odds of liver fibrosis progression significantly increased over two years for HIV mono-infected participants who drank alcohol hazardously (OR 3.038, P=0.048), and had BMI ≥ 28kg/m2 (OR 2.934, P=0.027). Cocaine use reduced the odds of advancing one stage of liver fibrosis (OR 0.228, P=0.038), but an interaction between high BMI and cocaine use slightly raised the odds by 4.8% of liver fibrosis progression (P=0.072). HIV/HCV co-infected participants showed interactions between cocaine use and high BMI with increased FIB-4 stage (OR 4.985, P= 0.034), however no lifestyle factors could independently predict FIB-4 stage in this group. Biological mediators previously associated with liver pathogenesis were associated with higher FIB-4 index over 2 years in a subset of (n=65) HIV mono-infected participants. Plasma measures of oxidative stress (% oxidized glutathione: OR 4.342, P= 0.046), hepatocyte-specific apoptosis (Cytokeratin-18 (CK-18): OR 1.008, P=0.021), and microbial endotoxin (lipopolysaccharide (LPS): OR 1.098, P= 0.097) were associated with having higher odds of progressing at least one stage of FIB-4 over 2 years. The same biological mediators were also associated with liver fibrosis within HIV infected people who also had a harmful lifestyle characteristic. FIB-4 index was significantly associated with % oxidized glutathione in obese subjects (β=0.563, P=0.018), TGF-β1 in cocaine users (β=0.858, P=0.027), and CK-18 in HIV infected individuals without any adverse lifestyle factors (β=0.435, P=0.015). Taken together, the findings of these studies describe interrelationships between HIV disease status, lifestyle, and biological mediators of liver fibrosis. The results show interactions between lifestyle conditions and the mediators of liver fibrosis may account for higher rates of liver disease in HIV infection. Research is warranted to develop personalized therapeutics for PLWH to curb the burden of liver disease.
324

Stabilization Schemes for Convection Dominated Scalar Problems with Different Time Discretizations in Time dependent Domains

Srivastava, Shweta January 2017 (has links) (PDF)
Problems governed by partial differential equations (PDEs) in deformable domains, t Rd; d = 2; 3; are of fundamental importance in science and engineering. They are of particular relevance in the design of many engineering systems e.g., aircrafts and bridges as well as to the analysis of several biological phenomena e.g., blood ow in arteries. However, developing numerical scheme for such problems is still very challenging even when the deformation of the boundary of domain is prescribed a priori. Possibility of excessive mesh distortion is one of the major challenge when solving such problems with numerical methods using boundary tted meshes. The arbitrary Lagrangian- Eulerian (ALE) approach is a way to overcome this difficulty. Numerical simulations of convection-dominated problems have for long been the subject to many researchers. Galerkin formulations, which yield the best approximations for differential equations with high diffusivity, tend to induce spurious oscillations in the numerical solution of convection dominated equations. Though such spurious oscillations can be avoided by adaptive meshing, which is computationally very expensive on ne grids. Alternatively, stabilization methods can be used to suppress the spurious oscillations. In this work, the considered equation is designed within the framework of ALE formulation. In the first part, Streamline Upwind Petrov-Galerkin (SUPG) finite element method with conservative ALE formulation is proposed. Further, the first order backward Euler and the second order Crank-Nicolson methods are used for the temporal discretization. It is shown that the stability of the semi-discrete (continuous in time) ALE-SUPG equation is independent of the mesh velocity, whereas the stability of the fully discrete problem is unconditionally stable for implicit Euler method and is only conditionally stable for Crank-Nicolson time discretization. Numerical results are presented to support the stability estimates and to show the influence of the SUPG stabilization parameter in a time-dependent domain. In the second part of this work, SUPG stabilization method with non-conservative ALE formulation is proposed. The implicit Euler, Crank-Nicolson and backward difference methods are used for the temporal discretization. At the discrete level in time, the ALE map influences the stability of the corresponding discrete scheme with different time discretizations, and it leads to schemes where conservative and non-conservative formulations are no longer equivalent. The stability of the fully discrete scheme, irrespective of the temporal discretization, is only conditionally stable. It is observed from numerical results that the Crank-Nicolson scheme induces high oscillations in the numerical solution compare to the implicit Euler and the backward difference time discretiza-tions. Moreover, the backward difference scheme is more sensitive to the stabilization parameter k than the other time discretizations. Further, the difference between the solutions obtained with the conservative and non-conservative ALE forms is significant when the deformation of domain is large, whereas it is negligible in domains with small deformation. Finally, the local projection stabilization (LPS) and the higher order dG time stepping scheme are studied for convection dominated problems. The analysis is based on the quadrature formula for approximating the integrals in time. We considered the exact integration in time, which is impractical to implement and the Radau quadrature in time, which can be used in practice. The stability and error estimates are shown for the mathematical basis of considered numerical scheme with both time integration methods. The numerical analysis reveals that the proposed stabilized scheme with exact integration in time is unconditionally stable, whereas Radau quadrature in time is conditionally stable with time-step restriction depending on the ALE map. The theoretical estimates are illustrated with appropriate numerical examples with distinct features. The second order dG(1) time discretization is unconditionally stable while Crank-Nicolson gives the conditional stable estimates only. The convergence order for dG(1) is two which supports the error estimate.
325

Insight into the activation mechanism of Toll-like receptor 4 by diC14-amidine

Schmidt, Boris 12 September 2014 (has links)
SUMMARY:<p>The bacterial lipopolysaccharide (LPS)-sensing machinery with the innate immune system receptor Toll-like receptor 4 (TLR4) at its centre has been the subject of extensive research but while TLR4 and myeloid differentiation factor 2 (MD2) were both shown to be essential, the role of other, so-called "accessory", molecules is much less clear. The co-receptor cluster of differentiation 14 (CD14) has been widely perceived as being a mere facilitator for the capture and transfer of LPS to TLR4, until recent studies suggested it might have a determining influence on which TLR4-dependent signaling cascades are triggered in response to LPS. The TLR4 receptor complex was shown to be specifically activated by diC14 amidine, a cationic lipid originally synthesized for its carrier properties. The lipid's immunostimulatory activity extends to both TLR4-dependent signaling cascades, the MyD88 and TRIF pathways.<p>The aim of this work was to gain more insight into how diC14 amidine is able to trigger these cascades and to contribute to the general understanding of the TLR4 machinery and its activation by non-LPS ligands. More precisely we were interested in the role of CD14 in the activation of both MyD88 and TRIF pathways by diC14-amidine and in potential consequences of possible divergent requirements of diC14 amidine and LPS for this co receptor.<p>Our study of the role of the membrane-associated and the soluble form of CD14 in the activation of the TLR4-dependent pathways by diC14 amidine revealed that – unlike LPS – the cationic lipid does not require CD14 to exercise its immunostimulatory activity, although the presence of the co receptor modulates the TLR4 activation and infrared spectroscopy experiments suggest a direct interaction.<p>In the case of sensing LPS, CD14 is required for the endocytosis of TLR4 and the subsequent activation of the TRIF pathway. By blocking the endocytosis mechanism at different stages we found that diC14-amidine generally enters the cell via endocytosis and that it activates – unlike LPS – both signaling cascades from inside endosomal vesicles, albeit at different stages of the endocytosis process.<p>Although the eventual immunological responses caused by diC14 amidine and LPS resemble each other or are even identical, our research revealed differences in the actual mechanism of activating TLR4, the receptor responsible for the corresponding innate immune response. These findings illustrate the uniqueness of diC14 amidine and the potential of further exploring its intriguing properties and mechanisms as a tool to decipher the TLR4 signaling machinery and with the perspective of designing new immunomodulators for vaccination and therapy.<p><p><p>RÉSUMÉ:<p>Le mécanisme de reconnaissance des lipopolysaccharides bactériens (LPS) par le récepteur de l'immunité innée Toll-like receptor 4 (TLR4) a fait l'objet d'une recherche intensive ces dernières années. Alors que TLR4 et son co-récepteur myeloid differentiation factor 2 (MD2) ont été démontrés comme étant essentiels pour la détection du LPS, le rôle des molécules dites "accessoires" est beaucoup moins évident. Le co-récepteur cluster of differentiation 14 (CD14) a largement été considéré comme un simple facilitateur pour la capture et le transfert des LPS à TLR4, mais des études récentes suggèrent qu'il pourrait avoir une influence déterminante sur les cascades de signalisation dépendantes de TLR4 induites en réponse au LPS. La diC14-amidine, un lipide cationique synthétisé initialement pour ses qualités en tant que vecteur de transfection, a révélé récemment une activité immunostimulatrice dépendante du récepteur TLR4, impliquant les deux cascades de signalisation dépendantes de TLR4, les voies MyD88 et TRIF.<p>Le but de ce travail était de mieux comprendre le mécanisme par lequel la diC14¬ amidine induit ces cascades et de contribuer à la compréhension générale du fonctionnement du complexe récepteur TLR4 et son activation par des ligands non-LPS. Plus précisément nous nous sommes intéressés au rôle de CD14 dans l'activation des voies MyD88 et TRIF par la diC14-amidine et des conséquences potentielles d’éventuelles divergences en termes d’exigence pour ce co-récepteur entre la diC14-amidine et le LPS. <p>Notre étude sur le rôle de la forme membranaire ou soluble de CD14 dans l'activation des voies dépendantes de TLR4 par la diC14-amidine a révélé que - contrairement au LPS - le lipide cationique ne nécessite pas de CD14 pour exercer son activité immunostimulatrice. Cependant, la présence du co-récepteur module l'activation de TLR4 et des expériences de spectroscopie infrarouge suggèrent une interaction directe entre le lipide et le CD14. <p>Dans le cas de la détection de LPS, le CD14 est nécessaire pour l'endocytose de TLR4 et l'activation subséquente de la voie TRIF. En bloquant le mécanisme d'endocytose à différents stades, nous avons montré que la diC14-amidine active - contrairement au LPS - les deux cascades de signalisation depuis l'intérieur des vésicules endosomiales, mais à des stades différents du processus d'endocytose.<p>En conclusion, bien que les réponses immunologiques causées par la diC14-amidine et le LPS se ressemblent, notre recherche a mis en évidence des différences substantielles dans leurs modes d'action. Ces différences illustrent le caractère unique de la diC14-amidine et son potentiel comme outil pour explorer la complexité du système de signalisation du TLR4 et en tirer des enseignements qui permettront de contribuer à la conception de nouveaux immunomodulateurs pour la vaccination et la thérapie. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
326

The IM-9 cell line: a model for evaluating TCDD-induced modulation of the polymorphic human hs1,2 enhancer within the 3' immunoglobulin heavy chain regulatory region

Chambers-Turner, Ruth C. 26 March 2010 (has links)
No description available.
327

Characterisation of anandamide uptake in resting and activated murine cells

Fredriksson Sundbom, Marcus January 2015 (has links)
Modifying the metabolism of the body’s own endocannabinoids is a novel approach for analgesia. Two key catabolic enzymes are fatty acid amide hydrolase (FAAH) and inflammation-inducible cyclooxygenase 2 (COX-2). The cellular uptake of the key endocannabinoid anandamide (AEA) has been found to be regulated by its FAAH-catalysed intracellular degradation, but COX-2 has not been investigated in this respect. We aimed to find out whether or not COX-2 in an in vitro inflammation setting would be able to gate AEA uptake. To achieve this, C6 cells and Raw 264.7 cells were stimulated with LPS/INF-γ and lysates then analyzed by immunoblot in order to verify COX-2 expression. AEA cellular uptake was quantified using a radioassay with [3H]-AEA. It was found that COX-2 was not inducible in C6 cells using the LPS/INF-γ conditions studied, while it was inducible in Raw 264.7 cells. AEA uptake in the COX-2-induced Raw 264.7 cells was not reduced by inhibitors of this enzyme. FAAH appeared to be down-regulated in the stimulated Raw 264.7 cells, and this was reflected in an overall lower AEA uptake. Our interpretation of the data points to FAAH as gating AEA uptake. Additional experiments are required to validate our findings by verifying significance.
328

Analyses on tech-enhanced and anonymous Peer Discussion as well as anonymous Control Facilities for tech-enhanced Learning / Analysen zur technologieunterstützten und anonymem Peer Discussion sowie anonymen Einflusswerkzeuge für technologieunterstütztes Lernen

Hara, Tenshi 12 September 2016 (has links) (PDF)
An increasing number of university freshmen has been observable in absolute number as well as percentage of population over the last decade. However, at the same time the drop-out rate has increased significantly. While a drop in attendance could be observed at the same time, statistics show that young professionals consider only roughly thirty percent of their qualification to originate in their university education. Taking this into consideration with the before mentioned, one conclusion could be that students fail to see the importance of fundamental classes and choose to seek knowledge elsewhere, for example in free online courses. However, the so acquired knowledge is a non-attributable qualification. One solution to this problem must be to make on-site activities more attractive. A promising approach for raised attractiveness would be to support students in self-regulated learning processes, making them experience importance and value of own decisions based on realistic self-assessment and self-evaluation. At the same time, strict ex-cathedra teaching should be replaced by interactive forms of education, ideally activating on a meta-cognitive level. Particularly, as many students bring mobile communication devices into classes, this promising approach could be extended by utilising these mobile devices as second screens. That way, enhanced learning experiences can be provided. The basic idea is simple, namely to contribute to psychological concepts with the means of computer science. An example for this idea are audience response systems. There has been numerous research into these and related approaches for university readings, but other forms of education have not been sufficiently considered, for example tutorials. This technological aspect can be combined with recent didactics research and concepts like peer instruction or visible learning. Therefore, this dissertation presents an experimental approach at providing existing IT solutions for on-site tutorials, specifically tools for audience responses, evaluations, learning demand assessments, peer discussion, and virtual interactive whiteboards. These tools are provided under observation of anonymity and cognisant incidental utilisation. They provide insight into students\' motivation to attend classes, their motivation to utilise tools, and into their tool utilisation itself. Experimental findings are combined into an extensible system concept consisting of three major tool classes: anonymous peer discussion means, anonymous control facilities, and learning demand assessment. With the exception of the latter, promising findings in context of tutorials are presented, for example the reduction of audience response systems to an emergency brake, the versatility of (peer) discussion systems, or a demand for retroactive deanonymisation of contributions. The overall positive impact of tool utilisation on motivation to attend and perceived value of tutorials is discussed and supplemented by a positive impact on the final exams\' outcomes. / Über die vergangene Dekade ist eine zunehmende Zahl Studienanfänger beobachtbar, sowohl in der absoluten Anzahl, als auch im Bevölkerungsanteil. Demgegenüber steht aber eine überproportional hohe Steigerung der Abbruchquote. Während gleichzeitig die Anwesenheit in universitären Lehrveranstaltungen sinkt, zeigen Statistiken, dass nur etwa ein Drittel der Berufseinsteiger die Grundlagen ihrer Qualifikation im Studium sieht. Daraus könnte man ableiten, dass Studierende den Wert und die Bedeutung universitärer Ausbildung unterschätzen und stattdessen Wissen in anderen Quellen suchen, beispielsweise unentgeltlichen Online-Angeboten. Das auf diese Art angeeignete Wissen stellt aber eine formell nicht nachweise Qualifikation dar. Ein Weg aus diesem Dilemma muss die Steigerung der Attraktivität der universitären Lehrveranstaltungen sein. Ein vielversprechender Ansatz ist die Unterstützung der Studierenden im selbst-regulierten Lernen, wodurch sie die Wichtigkeit und den Wert eigener Entscheidung(sfindungsprozesse) auf Basis realistischer Selbsteinschätzung und Selbstevaluation erlernen. Gleichzeitig sollte Frontalunterricht durch interaktive Lehrformen ersetzt werden, idealerweise durch Aktivierung auf meta-kognitiver Ebene. Dies ist vielversprechend insbesondere, weil viele Studierende ihre eigenen mobilen Endgeräte in Lehrveranstaltungen bringen. Diese Geräte können als Second Screen für die neuen Lehrkonzepte verwendet werden. Auf diese Art kann dann eine verbesserte Lernerfahrung vermittelt werden. Die Grundidee ist simpel, nämlich in der Psychologie bewährte Didaktik-Konzepte durch die Mittel der Informatik zu unterstützen. Ein Beispiel dafür sind Audience Response Systeme, die hinlänglich im Rahmen von Vorlesungen untersucht worden sind. Andere Lehrformen wurden dabei jedoch unzureichend berücksichtigt, beispielsweise Tutorien. Ähnliche Überlegungen gelten natürlich auch für bewährte didaktische Konzepte wie Peer Instruction oder Betrachtungen in Form von Visible Learning. Deshalb präsentiert diese Dissertation einen experimentellen Ansatz, informationstechnische Lösungen für vor-Ort-Übungen anzubieten, nämlich Werkzeuge für Audience Response Systeme, Evaluationen, Lernbedarfsermittlung, Peer Discussion, sowie virtuelle interaktive Whiteboards. Die genannten Werkzeuge wurden unter Beachtung von Anonymitäts- und Beiläufigkeitsaspekten bereitgestellt. Sie erlauben einen Einblick in die Motivation der Studierenden Tutorien zu besuchen und die Werkzeuge zu nutzen, sowie ihr Nutzungsverhalten selbst. Die experimentellen Ergebnisse werden in ein erweiterbares Systemkonzept kombiniert, das drei Werkzeugklassen unterstützt: anonyme Peer Discussion, anonyme Kontrollwerkzeuge und Lernbedarfsermittlung. Für die ersten beiden Klassen liegen vielversprechende Ergebnisse vor, beispielsweise die notwendige Reduktion des Audience Response Systems auf eine Art Notbremse, die Vielseitigkeit von (Peer-)Discussion-Systemen, oder aber auch der Bedarf für eine retroaktive Deanonymisierung von initial anonymen Beiträgen. Der allgemein positive Einfluss der Werkzeugnutzung auf die Motivation an Tutorien teilzunehmen sowie den wahrgenommenen Wert der Tutorien werden abschließend diskutiert und durch verbesserte Abschlussklausurergebnisse untermauert.
329

Analyses on tech-enhanced and anonymous Peer Discussion as well as anonymous Control Facilities for tech-enhanced Learning

Hara, Tenshi 14 June 2016 (has links)
An increasing number of university freshmen has been observable in absolute number as well as percentage of population over the last decade. However, at the same time the drop-out rate has increased significantly. While a drop in attendance could be observed at the same time, statistics show that young professionals consider only roughly thirty percent of their qualification to originate in their university education. Taking this into consideration with the before mentioned, one conclusion could be that students fail to see the importance of fundamental classes and choose to seek knowledge elsewhere, for example in free online courses. However, the so acquired knowledge is a non-attributable qualification. One solution to this problem must be to make on-site activities more attractive. A promising approach for raised attractiveness would be to support students in self-regulated learning processes, making them experience importance and value of own decisions based on realistic self-assessment and self-evaluation. At the same time, strict ex-cathedra teaching should be replaced by interactive forms of education, ideally activating on a meta-cognitive level. Particularly, as many students bring mobile communication devices into classes, this promising approach could be extended by utilising these mobile devices as second screens. That way, enhanced learning experiences can be provided. The basic idea is simple, namely to contribute to psychological concepts with the means of computer science. An example for this idea are audience response systems. There has been numerous research into these and related approaches for university readings, but other forms of education have not been sufficiently considered, for example tutorials. This technological aspect can be combined with recent didactics research and concepts like peer instruction or visible learning. Therefore, this dissertation presents an experimental approach at providing existing IT solutions for on-site tutorials, specifically tools for audience responses, evaluations, learning demand assessments, peer discussion, and virtual interactive whiteboards. These tools are provided under observation of anonymity and cognisant incidental utilisation. They provide insight into students\' motivation to attend classes, their motivation to utilise tools, and into their tool utilisation itself. Experimental findings are combined into an extensible system concept consisting of three major tool classes: anonymous peer discussion means, anonymous control facilities, and learning demand assessment. With the exception of the latter, promising findings in context of tutorials are presented, for example the reduction of audience response systems to an emergency brake, the versatility of (peer) discussion systems, or a demand for retroactive deanonymisation of contributions. The overall positive impact of tool utilisation on motivation to attend and perceived value of tutorials is discussed and supplemented by a positive impact on the final exams\' outcomes.:List of Definitions, Theorems and Proofs List of Figures List of Tables Introduction and Motivation Part I: Propaedeutics 1 Working Theses 1.1 Definitions 1.2 Context of Working Theses and Definitions 2 Existing Concepts 2.1 Psychology 2.1.1 Self-Regulation and self-regulated Learning 2.1.2 Peer Instruction, Peer Discussion 2.1.3 Learning Process Supervision: Learning Demand Assessment 2.1.4 Cognitive Activation 2.1.5 Note on Gamification 2.1.6 Note on Blended Learning 2.2 Computer Science 2.2.1 Learning Platforms 2.2.2 Audience Response Systems (ARS) 2.2.3 Virtual Interactive Whiteboard Systems (V-IWB) 2.2.4 Cognisant Incidential Utilisation (CIU) 2.3 Appraisal 3 Related Work 3.1 Visible Learning 3.2 auditorium 3.3 Auditorium Mobile Classroom Service 3.4 ARSnova and other Audience Response Systems 3.5 Google Classroom 3.6 StackOverflow 3.7 AwwApp Part II: Proceedings 4 Global Picture and Prototype 4.1 Global Picture 4.2 System Architecture 4.2.1 Anonymous Discussion Means 4.2.2 Anonymous Control Facilities 4.3 Implementation 4.3.1 The Prototype 5 Investigated Tools 5.1 Note on Methodology 5.2 Anonymity 5.2.1 Methodology 5.2.2 Visible Learning Effects 5.2.3 Assertion 5.2.4 Experiments 5.2.5 Results 5.2.6 Conclusions 5.3 Learning Demand Assessment 5.3.1 Methodology 5.3.2 Visible Learning Effects 5.3.3 Tool Description 5.3.4 Assertion 5.3.5 Experiments 5.3.6 Results 5.3.7 Conclusions 5.4 Peer Discussion System 5.4.1 Methodology 5.4.2 Visible Learning Effects 5.4.3 Tool Description 5.4.4 Assertion 5.4.5 Experiments 5.4.6 Results 5.4.7 Conclusions 5.5 Virtual Interactive Whiteboard 5.5.1 Methodology 5.5.2 Visible Learning Effects 5.5.3 Tool Description 5.5.4 Assertion 5.5.5 Experiments 5.5.6 Results 5.5.7 Conclusions 5.6 Audience Response System and Emergency Brake 5.6.1 Methodology 5.6.2 Visible Learning Effects 5.6.3 Tool Description 5.6.4 Assertion 5.6.5 Experiments 5.6.6 Results 5.6.7 Conclusions 5.7 Evaluation System 5.7.1 Methodology 5.7.2 Visible Learning Effects 5.7.3 Tool Description 5.7.4 Assertion 5.7.5 Experiments 5.7.6 Results and Conclusion 6 Exam Outcome 7 Utilisation and Motivation 7.1 Prototype Utilisation 7.2 Motivational Aspects Part III: Appraisal 8 Lessons learned 9 Discussion 9.1 Working Theses’ Validity 9.2 Research Community: Impact and Outlook 9.2.1 Significance to Learning Psychology 9.3 Possible Extension of existing Solutions 10 Conclusion 10.1 Summary of scientific Contributions 10.2 Future Work Part IV: Appendix A Experimental Arrangement B Questionnaires B.1 Platform Feedback Sheet B.1.1 Original PFS in 2014 B.1.2 Original PFS in 2015 B.2 Minute Paper B.3 Motivation and Utilisation Questionnaires B.3.1 Motivation 2013 and 2014 B.3.2 Motivation 2015 B.3.3 Utilisation 2014 B.3.4 Utilisation 2015, Rev. I B.3.5 Utilisation 2015, Rev. II C References C.1 Auxiliary Means D Publications D.1 Original Research Contributions D.2 Student Theses E Glossary F Index G Milestones Acknowledgements / Über die vergangene Dekade ist eine zunehmende Zahl Studienanfänger beobachtbar, sowohl in der absoluten Anzahl, als auch im Bevölkerungsanteil. Demgegenüber steht aber eine überproportional hohe Steigerung der Abbruchquote. Während gleichzeitig die Anwesenheit in universitären Lehrveranstaltungen sinkt, zeigen Statistiken, dass nur etwa ein Drittel der Berufseinsteiger die Grundlagen ihrer Qualifikation im Studium sieht. Daraus könnte man ableiten, dass Studierende den Wert und die Bedeutung universitärer Ausbildung unterschätzen und stattdessen Wissen in anderen Quellen suchen, beispielsweise unentgeltlichen Online-Angeboten. Das auf diese Art angeeignete Wissen stellt aber eine formell nicht nachweise Qualifikation dar. Ein Weg aus diesem Dilemma muss die Steigerung der Attraktivität der universitären Lehrveranstaltungen sein. Ein vielversprechender Ansatz ist die Unterstützung der Studierenden im selbst-regulierten Lernen, wodurch sie die Wichtigkeit und den Wert eigener Entscheidung(sfindungsprozesse) auf Basis realistischer Selbsteinschätzung und Selbstevaluation erlernen. Gleichzeitig sollte Frontalunterricht durch interaktive Lehrformen ersetzt werden, idealerweise durch Aktivierung auf meta-kognitiver Ebene. Dies ist vielversprechend insbesondere, weil viele Studierende ihre eigenen mobilen Endgeräte in Lehrveranstaltungen bringen. Diese Geräte können als Second Screen für die neuen Lehrkonzepte verwendet werden. Auf diese Art kann dann eine verbesserte Lernerfahrung vermittelt werden. Die Grundidee ist simpel, nämlich in der Psychologie bewährte Didaktik-Konzepte durch die Mittel der Informatik zu unterstützen. Ein Beispiel dafür sind Audience Response Systeme, die hinlänglich im Rahmen von Vorlesungen untersucht worden sind. Andere Lehrformen wurden dabei jedoch unzureichend berücksichtigt, beispielsweise Tutorien. Ähnliche Überlegungen gelten natürlich auch für bewährte didaktische Konzepte wie Peer Instruction oder Betrachtungen in Form von Visible Learning. Deshalb präsentiert diese Dissertation einen experimentellen Ansatz, informationstechnische Lösungen für vor-Ort-Übungen anzubieten, nämlich Werkzeuge für Audience Response Systeme, Evaluationen, Lernbedarfsermittlung, Peer Discussion, sowie virtuelle interaktive Whiteboards. Die genannten Werkzeuge wurden unter Beachtung von Anonymitäts- und Beiläufigkeitsaspekten bereitgestellt. Sie erlauben einen Einblick in die Motivation der Studierenden Tutorien zu besuchen und die Werkzeuge zu nutzen, sowie ihr Nutzungsverhalten selbst. Die experimentellen Ergebnisse werden in ein erweiterbares Systemkonzept kombiniert, das drei Werkzeugklassen unterstützt: anonyme Peer Discussion, anonyme Kontrollwerkzeuge und Lernbedarfsermittlung. Für die ersten beiden Klassen liegen vielversprechende Ergebnisse vor, beispielsweise die notwendige Reduktion des Audience Response Systems auf eine Art Notbremse, die Vielseitigkeit von (Peer-)Discussion-Systemen, oder aber auch der Bedarf für eine retroaktive Deanonymisierung von initial anonymen Beiträgen. Der allgemein positive Einfluss der Werkzeugnutzung auf die Motivation an Tutorien teilzunehmen sowie den wahrgenommenen Wert der Tutorien werden abschließend diskutiert und durch verbesserte Abschlussklausurergebnisse untermauert.:List of Definitions, Theorems and Proofs List of Figures List of Tables Introduction and Motivation Part I: Propaedeutics 1 Working Theses 1.1 Definitions 1.2 Context of Working Theses and Definitions 2 Existing Concepts 2.1 Psychology 2.1.1 Self-Regulation and self-regulated Learning 2.1.2 Peer Instruction, Peer Discussion 2.1.3 Learning Process Supervision: Learning Demand Assessment 2.1.4 Cognitive Activation 2.1.5 Note on Gamification 2.1.6 Note on Blended Learning 2.2 Computer Science 2.2.1 Learning Platforms 2.2.2 Audience Response Systems (ARS) 2.2.3 Virtual Interactive Whiteboard Systems (V-IWB) 2.2.4 Cognisant Incidential Utilisation (CIU) 2.3 Appraisal 3 Related Work 3.1 Visible Learning 3.2 auditorium 3.3 Auditorium Mobile Classroom Service 3.4 ARSnova and other Audience Response Systems 3.5 Google Classroom 3.6 StackOverflow 3.7 AwwApp Part II: Proceedings 4 Global Picture and Prototype 4.1 Global Picture 4.2 System Architecture 4.2.1 Anonymous Discussion Means 4.2.2 Anonymous Control Facilities 4.3 Implementation 4.3.1 The Prototype 5 Investigated Tools 5.1 Note on Methodology 5.2 Anonymity 5.2.1 Methodology 5.2.2 Visible Learning Effects 5.2.3 Assertion 5.2.4 Experiments 5.2.5 Results 5.2.6 Conclusions 5.3 Learning Demand Assessment 5.3.1 Methodology 5.3.2 Visible Learning Effects 5.3.3 Tool Description 5.3.4 Assertion 5.3.5 Experiments 5.3.6 Results 5.3.7 Conclusions 5.4 Peer Discussion System 5.4.1 Methodology 5.4.2 Visible Learning Effects 5.4.3 Tool Description 5.4.4 Assertion 5.4.5 Experiments 5.4.6 Results 5.4.7 Conclusions 5.5 Virtual Interactive Whiteboard 5.5.1 Methodology 5.5.2 Visible Learning Effects 5.5.3 Tool Description 5.5.4 Assertion 5.5.5 Experiments 5.5.6 Results 5.5.7 Conclusions 5.6 Audience Response System and Emergency Brake 5.6.1 Methodology 5.6.2 Visible Learning Effects 5.6.3 Tool Description 5.6.4 Assertion 5.6.5 Experiments 5.6.6 Results 5.6.7 Conclusions 5.7 Evaluation System 5.7.1 Methodology 5.7.2 Visible Learning Effects 5.7.3 Tool Description 5.7.4 Assertion 5.7.5 Experiments 5.7.6 Results and Conclusion 6 Exam Outcome 7 Utilisation and Motivation 7.1 Prototype Utilisation 7.2 Motivational Aspects Part III: Appraisal 8 Lessons learned 9 Discussion 9.1 Working Theses’ Validity 9.2 Research Community: Impact and Outlook 9.2.1 Significance to Learning Psychology 9.3 Possible Extension of existing Solutions 10 Conclusion 10.1 Summary of scientific Contributions 10.2 Future Work Part IV: Appendix A Experimental Arrangement B Questionnaires B.1 Platform Feedback Sheet B.1.1 Original PFS in 2014 B.1.2 Original PFS in 2015 B.2 Minute Paper B.3 Motivation and Utilisation Questionnaires B.3.1 Motivation 2013 and 2014 B.3.2 Motivation 2015 B.3.3 Utilisation 2014 B.3.4 Utilisation 2015, Rev. I B.3.5 Utilisation 2015, Rev. II C References C.1 Auxiliary Means D Publications D.1 Original Research Contributions D.2 Student Theses E Glossary F Index G Milestones Acknowledgements

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