3,108 research outputs found

    Preconditioning for Allen-Cahn variational inequalities with non-local constraints

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    The solution of Allen-Cahn variational inequalities with mass constraints is of interest in many applications. This problem can be solved both in its scalar and vector-valued form as a PDE-constrained optimization problem by means of a primal-dual active set method. At the heart of this method lies the solution of linear systems in saddle point form. In this paper we propose the use of Krylov-subspace solvers and suitable preconditioners for the saddle point systems. Numerical results illustrate the competitiveness of this approach

    Allen-Cahn and Cahn-Hilliard variational inequalities solved with Optimization Techniques

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    Parabolic variational inequalities of Allen-Cahn and Cahn- Hilliard type are solved using methods involving constrained optimization. Time discrete variants are formulated with the help of Lagrange multipliers for local and non-local equality and inequality constraints. Fully discrete problems resulting from finite element discretizations in space are solved with the help of a primal-dual active set approach. We show several numerical computations also involving systems of parabolic variational inequalities

    Auswirkungen der Fröbelpädagogik auf das Umweltbewusstsein im Sachunterricht

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    Naturverbundenheit gilt als ein entscheidender Prädiktor für Umweltbewusstsein und somit für umweltfreundliches Verhalten1. Um der vorherrschenden ökologischen Krise entgegenzuwirken, ist eine erfolgreiche Rückbindung des Einzelnen an die Natur erforderlich. Auch Friedrich Fröbel sah in seinem Bildungs- und Erziehungsmodell die Einbeziehung der Natur als grundlegend an, sowohl für eine gesunde Entwicklung, als auch als entscheidend für die Ausbildung ethischen Verhaltens2. Diese Masterarbeit untersucht die Auswirkungen der Anwendung von Elementen der Pädagogik Friedrich Fröbels im Sachunterricht auf die Naturverbundenheit von Grundschulkindern. Anwendung findet hier ein quasiexperimentelles Forschungsdesign, welches in drei Phasen angelegt ist. Die geplanten Befragungen mittels standardisierter Fragebögen gehören zur ersten und dritten Phase und bilden den Pre- und Posttest. In diesen Phasen soll durch die Nutzung des Connection to Nature Index (CNI) nach Cheng/Monroe 2012 die Verbundenheit zur Natur erforscht werden3. Die Intervention in der zweiten Phase wurde innerhalb von drei Schulstunden zur Thematik Überwinterungsstrategien von Pflanzen und Bäumen im Sachunterricht durchgeführt. Kinder aus der Parallelklasse, die nicht an der Intervention teilnahmen, erhielten Klassenunterricht zu diesem Thema und dienten somit als Kontrollgruppe. Die Ergebnisse deuten darauf hin, dass die Anwendung fröbelpädagogischer Elemente im Sachunterricht eine stärkere Naturverbundenheit der Lernenden hervorruft, als signifikant erwies sich diese Aussage jedoch nicht (p = .129). ------------- 1 Vgl. Cervinka/Schmuck 2010, zitiert nach Cervinka, Renate/Schwab, Markus (2020): Naturverbundenheit – Ergebnisse der umweltpsychologischen Forschung für Agrar- und Umweltpädagogik und Green Care. In: Zeitschrift für Agrar- und Umweltpädagogische Forschung, Band 2, S. 10. 2 Vgl. Frey, Andreas/Gehrlein, Birgit/Wosnitza, Marold (2001): Fröbels ganzheitliche Pädagogik. Landau: Verlag Empirischer Pädagogik, S. 76f. 3 Vgl. Cheng, Judith Chen-Hsuan/Monroe, Martha C. (2012): Connection to nature: Children’s affective attitude toward nature. In: Environment and Behavior, 44, 1, S. 31

    Dissection of human papillomavirus type 33 L2 domains involved in nuclear domains (ND) 10 homing and reorganization

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    AbstractWe have recently shown that the minor capsid protein L2 of human papillomavirus type 33 (HPV33) recruits the transcriptional repressor Daxx into nuclear domains (ND) 10 and causes the loss of the transcriptional activator Sp100 from these subnuclear structures (Florin et al., 2002b). In order to dissect L2 domains involved in nuclear translocation, ND10 homing, loss of Sp100, and recruitment of Daxx, a detailed deletion mutagenesis of L2 was performed. Using immunofluorescence and green fluorescent protein fusions, we have identified two nuclear localization signals (NLS) in the central and C-terminal part of L2, respectively, homologous to previously identified NLS in HPV6B L2 (Sun et al., 1995). We mapped the ND10 localization domain to within a 30 amino acid peptide in the C-terminal half of L2. L2-induced attraction of Daxx into ND10, coimmunoprecipitation of L2 and Daxx, as well as induction of the loss of Sp100 from ND10 require an intact ND10 localization domain. This domain contains conserved PXXP motives characteristic of some protein/protein interacting domains. Our data also suggest that the Daxx/L2 interaction may be the driving force for L2 accumulation in ND10

    Quality of life in patients with severe mental illness: a cross-sectional survey in an integrated outpatient health care model

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    Purpose: This study (a) assessed quality of life (QoL) in a patient sample with severe mental illness in an integrated psychiatric care (IC) programme in selected regions in Germany, (b) compared QoL among diagnostic groups and (c) identified socio-demographic, psychiatric anamnestic and clinical characteristics associated with QoL. Methods: This cross-sectional study included severely mentally ill outpatients with substantial impairments in social functioning. Separate dimensions of QoL were assessed with the World Health Organisation’s generic 26-item quality of life (WHOQOL-BREF) instrument. Descriptive analyses and analyses of variance (ANOVAs) were conducted for the overall sample as well as for diagnostic group. Results: A total of 953 patients fully completed the WHOQOL-BREF questionnaire. QoL in this sample was lower than in the general population (mean 34.1; 95% confidence interval (CI) 32.8 to 35.5), with the lowest QoL in unipolar depression patients (mean 30.5; 95% CI 28.9 to 32.2) and the highest in dementia patients (mean 53.0; 95% CI 47.5 to 58.5). Main psychiatric diagnosis, living situation (alone, partner/relatives, assisted), number of disease episodes, source of income, age and clinical global impression (CGI) scores were identified as potential predictors of QoL, but explained only a small part of the variation. Conclusion: Aspects of health care that increase QoL despite the presence of a mental disorder are essential for severely mentally ill patients, as complete freedom from the disorder cannot be expected. QoL as a patient-centred outcome should be used as only one component among the recovery measures evaluating treatment outcomes in mental health care

    A phase I/II trial to evaluate the safety, feasibility and activity of salvage therapy consisting of the mTOR inhibitor Temsirolimus added to standard therapy of Rituximab and DHAP for the treatment of patients with relapsed or refractory diffuse large cell B-Cell lymphoma - the STORM trial

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    Background: The current standard treatment of patients with relapsed or refractory diffuse large cell B-Cell lymphoma (DLBCL) primarily consists of intensified salvage therapy and, if the disease is chemo-sensitive, high dose therapy followed with autologous stem cell transplantation. In the rituximab era however, this treatment approach has shown only limited benefit. In particular, patients relapsing after rituximab-containing primary treatment have an adverse prognosis, especially if this occurs within the first year after therapy or if the disease is primarily refractory. Therefore there is an ultimate need for improved salvage treatment approaches. Methods/design: The STORM study is a prospective, multicentre phase I/II study to evaluate the safety, feasibility and activity of salvage therapy consisting of the mTOR inhibitor temsirolimus added to the standard therapy rituximab and DHAP for the treatment of patients with relapsed or refractory DLBCL. The primary objective of the phase I of the trial is to establish the maximum tolerated dose (MTD) of temsirolimus in combination with rituximab and DHAP. The secondary objective is to demonstrate that stem cells can be mobilized during this regimen in patients scheduled to proceed to high dose therapy. In phase II, the previously established maximum tolerated dose of temsirolimus will be used. The primary objective is to evaluate the overall response rate (ORR) in patients with relapsed DLBCL. The secondary objective is to evaluate progression free survival (PFS), overall survival (OS) and toxicity. The study will be accompanied by an analysis of lymphoma subtypes determined by gene expression analysis (GEP). Discussion: The STORM trial evaluates the safety, feasibility and activity of salvage therapy consisting of the mTOR inhibitor temsirolimus added to standard therapy of rituximab and DHAP for the treatment of patients with relapsed or refractory DLBCL. It also might identify predictive markers for this treatment modality

    Mapping the depleted area of silicon diodes using a micro-focused X-ray beam

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    For the Phase-II Upgrade of the ATLAS detector at CERN, the current ATLAS Inner Detector will be replaced with the ATLAS Inner Tracker. The ATLAS Inner Tracker will be an all-silicon detector, consisting of a pixel tracker and a strip tracker. Sensors for the ITk strip tracker are required to have a low leakage current up to bias voltages of -700 V to maintain a low noise and power dissipation. In order to minimise sensor leakage currents, particularly in the high-radiation environment inside the ATLAS detector, sensors are foreseen to be operated at low temperatures and to be manufactured from wafers with a high bulk resistivity of several k{\Omega} cm. Simulations showed the electric field inside sensors with high bulk resistivity to extend towards the sensor edge, which could lead to increased surface currents for narrow dicing edges. In order to map the electric field inside biased silicon sensors with high bulk resistivity, three diodes from ATLAS silicon strip sensor prototype wafers were studied with a monochromatic, micro-focused X-ray beam at the Diamond Light Source. For all devices under investigation, the electric field inside the diode was mapped and its dependence on the applied bias voltage was studied. The findings showed that the electric field in each diode under investigation extended beyond its bias ring and reached the dicing edge

    Parameter Identification of Fiber Orientation Models Based on Direct Fiber Simulation with Smoothed Particle Hydrodynamics

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    The behavior of fiber suspensions during flow is of fundamental importance to the process simulation of discontinuous fiber reinforced plastics. However, the direct simulation of flexible fibers and fluid poses a challenging two-way coupled fluid-structure interaction problem. Smoothed Particle Hydrodynamics (SPH) offers a natural way to treat such interactions. Hence, this work utilizes SPH and a bead chain model to compute a shear flow of fiber suspensions. The introduction of a novel viscous surface traction term is key to achieve full agreement with Jeffery’s equation. Careful modelling of contact interactions between fibers is introduced to model suspensions in the non-dilute regime. Finally, parameters of the Reduced-Strain Closure (RSC) orientation model are identified using ensemble averages of multiple SPH simulations implemented in PySPH and show good agreement with literature data
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