1,313 research outputs found

    Regularization Dependence of the Zero Mode Dynamics in the Schwinger Model

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    I compare heatkernel regularization with sharp gauge invariant cutoffs in the Hamiltonian formulation of the Coulomb gauged Schwinger model on a circle. The effective potential for the zero mode of the gauge field in a given fermionic configuration is different in these two regularizations, the difference being independent of the chosen fermionic configuration. In the continuum limit the gauge field can be localized or delocalized depending on the regulator.Comment: 7 pages, latex , (revised because of TEX problem

    Agreement between youth-reported and parent-reported psychopathology in a referred sample

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    Objective: The study examined parent-youth agreement regarding reports on psychopathology among adolescents suffering from psychiatric disorders. Method: A total of 1,718 patients between the age of 11 and 18, as well as their parents, were assessed using the child behavior checklist (CBCL), and the youth self-report (YSR). Results: Poor to low agreement between parent- and adolescent-reported problem behavior on the internalizing scale, the total problem scale and moderate agreement concerning the externalizing scale of the CBCL and the YSR were found. Independent from the amount of psychiatric diagnoses, adolescents reported significantly less behavioral problems than their parents. Concerning externalizing problems, parent-youth disagreement was stronger for patients suffering from comorbid psychiatric disorders, than for adolescents displaying only one psychiatric disorder. Conclusion: In clinically referred children, parents are likely to emphasize the severity of the difficulties, whereas adolescents’ under-report symptoms

    Signal characteristics of focal bone marrow lesions in patients with multiple myeloma using whole body T1w-TSE, T2w-STIR and diffusion-weighted imaging with background suppression

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    Objective: This study analyses the diagnostic potential of Diffusion-Weighted Imaging with Background Suppression (DWIBS) in the detection of focal bone marrow lesions from multiple myeloma. The signal and contrast properties of DWIBS are evaluated in correlation with the serum concentration of M-component (MC) and compared with established T1- and T2-weighted sequences. Methods: Data from 103 consecutive studies in 81 patients are analysed retrospectively. Signal intensities and apparent Diffusion Coefficients (ADC) of 79 focal lesions in the lumbar spine or pelvis of 38 patients are determined and contrast-to-noise-ratio (CNR) is calculated. Data from patients with low (20g/dL) MC are evaluated separately. Results: Signal intensities of focal myeloma lesions on T2w-STIR vary significantly depending on the MC, which leads to a loss in CNR in patients with high MC. No signal variation is observed for T1w-TSE and DWIBS. The CNR values provided by DWIBS in patients with high MC are slightly higher than those of T2w-STIR. ADC values in patients with low MC are significantly higher than in patients with high MC. Conclusion: Whole-body DWIBS has the potential to improve the conspicuity of focal myeloma lesions and provides additional biological information by ADC quantificatio

    Predictive MGMT status in a homogeneous cohort of IDH wildtype glioblastoma patients

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    Methylation of the O(6)-Methylguanine-DNA methyltransferase (MGMT) promoter is predictive for treatment response in glioblastoma patients. However, precise predictive cutoff values to distinguish "MGMT methylated" from "MGMT unmethylated" patients remain highly debated in terms of pyrosequencing (PSQ) analysis. We retrospectively analyzed a clinically and molecularly very well-characterized cohort of 111 IDH wildtype glioblastoma patients, who underwent gross total tumor resection and received standard Stupp treatment. Detailed clinical parameters were obtained. Predictive cutoff values for MGMT promoter methylation were determined using ROC curve analysis and survival curve comparison using Log-rank (Mantel-Cox) test. MGMT status was analyzed using pyrosequencing (PSQ), semi-quantitative methylation specific PCR (sqMSP) and direct bisulfite sequencing (dBiSeq). Highly methylated (> 20%) MGMT correlated with significantly improved progression-free survival (PFS) and overall survival (OS) in our cohort. Median PFS was 7.2 months in the unmethylated group (UM, 20% mean methylation). Median OS was 13.4 months for UM, 17.9 months for LM and 29.93 months for HM. Within the LM group, correlation of PSQ and sqMSP or dBiSeq was only conclusive in 51.5% of our cases. ROC curve analysis revealed superior test precision for survival if additional sqMSP results were considered (AUC = 0.76) compared to PSQ (cutoff 10%) alone (AUC = 0.67). We therefore challenge the widely used, strict PSQ cutoff at 10% which might not fully reflect the clinical response to alkylating agents and suggest applying a second method for MGMT testing (e.g. MSP) to confirm PSQ results for patients with LM MGMT levels if therapeutically relevant

    Das Projekt "Kunst und Mathematik"

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    Ausgehend von verschiedenen Kunstwerken werden Verbindungen zwischen ästhetischen und mathematischen Erfahrungen herausgearbeitet. Diese werden zum Entwurf von Lernumgebungen genutzt, die im Rahmen der Praxisphase erprobt und auf ihre Wirkung hin überprüft werden. (DIPF/Orig.

    Between Poisson and GUE statistics: Role of the Breit-Wigner width

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    We consider the spectral statistics of the superposition of a random diagonal matrix and a GUE matrix. By means of two alternative superanalytic approaches, the coset method and the graded eigenvalue method, we derive the two-level correlation function X2(r)X_2(r) and the number variance Σ2(r)\Sigma^2(r). The graded eigenvalue approach leads to an expression for X2(r)X_2(r) which is valid for all values of the parameter λ\lambda governing the strength of the GUE admixture on the unfolded scale. A new twofold integration representation is found which can be easily evaluated numerically. For λ1\lambda \gg 1 the Breit-Wigner width Γ1\Gamma_1 measured in units of the mean level spacing DD is much larger than unity. In this limit, closed analytical expression for X2(r)X_2(r) and Σ2(r)\Sigma^2(r) can be derived by (i) evaluating the double integral perturbatively or (ii) an ab initio perturbative calculation employing the coset method. The instructive comparison between both approaches reveals that random fluctuations of Γ1\Gamma_1 manifest themselves in modifications of the spectral statistics. The energy scale which determines the deviation of the statistical properties from GUE behavior is given by Γ1\sqrt{\Gamma_1}. This is rigorously shown and discussed in great detail. The Breit-Wigner Γ1\Gamma_1 width itself governs the approach to the Poisson limit for rr\to\infty. Our analytical findings are confirmed by numerical simulations of an ensemble of 500×500500\times 500 matrices, which demonstrate the universal validity of our results after proper unfolding.Comment: 25 pages, revtex, 5 figures, Postscript file also available at http://germania.ups-tlse.fr/frah

    Rezensionen

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    Rezensionen zu folgenden Titeln: 1) Eirmbter-Stolbrink, Eva; König-Fuchs, Claudia: Erziehungswissenschaftliche Methodenforschung: Vermittlung und Aneignung von Wissen. Reinbek: Lau 2012. ISBN 978-3941400405. 2) Fahrenwald, Claudia: Erzählen im Kontext neuer Lernkulturen. Eine bildungstheoretische Analyse im Spannungsverhältnis von Wissen, Lernen und Subjekt. Wiesbaden: VS Verl. f. Sozialwiss. 2001. ISBN 978-3-531-18385-5. 3) Kerres, Michael: Mediendidaktik. Konzeption und Entwicklung mediengestützter Lernangebote. München: Oldenbourg 2012 (3., vollst. überarb. Aufl.). ISBN 978-3-486-27207-9. 4) Schmidt-Lauff, Sabine (Hg.): Zeit und Bildung: Annäherung an eine zeittheoretische Grundlegung. Münster: Waxmann 2012. ISBN 978-3-8309-2660-3. 5) Uhmann, Christine: Aktuelle Herausforderungen im Management von Weiterbildungsorganisationen. Hannover: ArtSet/EXPRESSUM-Verl. 2011. ISBN 978-3-89069-026-1

    Strategieoptionen zur Realisierung einer 100%igen Biofütterung bei Monogastriern im ökologischen Landbau

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    Die Umstellung auf 100%ige Biofütterung innerhalb der nächsten drei Jahre stellt eine große Herausforderung in der Monogastrierfütterung dar. Die in diesem Dossier vorgestellten Lösungsoptionen sind hinsichtlich ihrer Implementierungsmöglichkeit sehr unterschiedlich zu bewerten: Manche Optionen, wie beispielsweise die bakterielle Aminosäureherstellung, setzen noch erhebliche Forschungsarbeiten voraus, andere, wie die Verfütterung von bestimmten Silagen, sind bereits bewerte Praxis bei der Fütterung von Wiederkäuern, müssen allerdings erst noch auf Monogastrier angepasst werden. Während für die bakterielle Aminosäureherstellung entsprechende Bakterienstämme in ihrer Leistungsfähigkeit optimiert und geeignete Biosubstrate gefunden werden müssen, müssen bei der Silagebereitung und -verfütterung vor allem noch verbesserte technische Lösungen gefunden und installiert werden, damit das darin vorhandene Potenzial zur Entfaltung kommt

    Regionale Verteilung der Bakterien-Abundanz und Aktivität in der Unterelbe und Unterweser: Ein Vergleich zwischen beiden Ästuaren (=Regional distribution of bacterial abundance and activity in the Lower Elbe and Weser Rivers A comparison between both estuaries)

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    Die Mündungsgebiete von Elbe und Weser bilden die beiden größten deutschen Ästuare. Sie weisen eine Reihe von hydrologischen, geologischen und klimatischen Gemeinsamkeiten auf. Ziel der Arbeit war es zu untersuchen, ob und wieweit diese Gemeinsamkeiten auch in planktologisch/mikrobiologischer Hinsicht gelten. Hierzu wurden bei niedrigem Oberwasserabfluss im Juni 2005 Oberflächenproben in 10 km Abständen in beiden Ästuaren von ihrem limnischen Bereich bis in die Deutsche Bucht genommen. Untersucht wurden die abiotischen Parameter Temperatur, Salzgehalt, Gesamt- und Feintrübung < 2 μm sowie die biologischen Parameter Chlorophyll a und Phäopigmente, Bakterienzahl und bakterielle Biomasseproduktion. Die biologischen Variablen hatten ihr Maximum stets in der limnischen Zone. Hier beliefen sich die Werte in der Elbe auf 10,3 μg l-1 Chlorophyll a (Chl a), 9,5 x 109 l-1 Bakterien (BZ) und eine bakterielle Biomasseproduktion (BBP) von 4,3 μg C l-1 h-1. In der Weser lagen sie bei 22,5 μg l-1 (Chl a), 7,8 x 109 l-1 (BZ) und 4,1 μg C l-1 h-1 (BBP). Ein Minimum wurde im Bereich der oberen Brackwassergrenze mit 5,2 μg l-1 (Chl a), 5,4 x 109 l-1 (BZ) und 1,0 μg C l-1 h-1 (BBP) in der Elbe und mit 3,8 μg l-1 (Chl a), 7,4 x 109 l-1 (BZ) und 1,4 μg C l-1 h-1 (BBP) in der Weser gefunden. An der seewärtigen Grenze der Ästuarregionen trat ein erneutes Maximum auf. Damit stimmten beide Ästuare sowohl in der regionalen Verteilung als auch in der Größe der Parameter weitgehend überein

    Safety and immunogenicity of H1/IC31®, an adjuvanted TB subunit vaccine, in HIV-infected adults with CD4+ lymphocyte counts greater than 350 cells/mm3: a phase II, multi-centre, double-blind, randomized, placebo-controlled trial.

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    BACKGROUND: Novel tuberculosis vaccines should be safe, immunogenic, and effective in various population groups, including HIV-infected individuals. In this phase II multi-centre, double-blind, placebo-controlled trial, the safety and immunogenicity of the novel H1/IC31 vaccine, a fusion protein of Ag85B-ESAT-6 (H1) formulated with the adjuvant IC31, was evaluated in HIV-infected adults. METHODS: HIV-infected adults with CD4+ T cell counts >350/mm3 and without evidence of active tuberculosis were enrolled and followed until day 182. H1/IC31 vaccine or placebo was randomly allocated in a 5:1 ratio. The vaccine was administered intramuscularly at day 0 and 56. Safety assessment was based on medical history, clinical examinations, and blood and urine testing. Immunogenicity was determined by a short-term whole blood intracellular cytokine staining assay. RESULTS: 47 of the 48 randomised participants completed both vaccinations. In total, 459 mild or moderate and 2 severe adverse events were reported. There were three serious adverse events in two vaccinees classified as not related to the investigational product. Local injection site reactions were more common in H1/IC31 versus placebo recipients (65.0% vs. 12.5%, p = 0.015). Solicited systemic and unsolicited adverse events were similar by study arm. The baseline CD4+ T cell count and HIV viral load were similar by study arm and remained constant over time. The H1/IC31 vaccine induced a persistent Th1-immune response with predominately TNF-α and IL-2 co-expressing CD4+ T cells, as well as polyfunctional IFN-γ, TNF-α and IL-2 expressing CD4+ T cells. CONCLUSION: H1/IC31 was well tolerated and safe in HIV-infected adults with a CD4+ Lymphocyte count greater than 350 cells/mm3. The vaccine did not have an effect on CD4+ T cell count or HIV-1 viral load. H1/IC31 induced a specific and durable Th1 immune response. TRIAL REGISTRATION: Pan African Clinical Trials Registry (PACTR) PACTR201105000289276
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