„Mit Steuern steuern?“ Chancen und Grenzen gemeinwohlorientierter Fiskalpolitik

Bericht zu den 8. Heppenheimer Tagen zur christlichen Gesellschaftsethi

The wilms tumor gene wt1a contributes to blood-cerebrospinal fluid barrier function in zebrafish

The Wilms tumor suppressor gene Wt1 encodes a zinc finger transcription factor, which is highly conserved among vertebrates. It is a key regulator of urogenital development and homeostasis but also plays a role in other organs including the spleen and the heart. More recently additional functions for Wt1 in the mammalian central nervous system have been described. In contrast to mammals, bony fish possess two paralogous Wt1 genes, namely wt1a and wt1b. By performing detailed in situ hybridization analyses during zebrafish development, we discovered new expression domains for wt1a in the dorsal hindbrain, the caudal medulla and the spinal cord. Marker analysis identified wt1a expressing cells of the dorsal hindbrain as ependymal cells of the choroid plexus in the myelencephalic ventricle. The choroid plexus acts as a blood-cerebrospinal fluid barrier and thus is crucial for brain homeostasis. By employing wt1a mutant larvae and a dye accumulation assay with fluorescent tracers we demonstrate that Wt1a is required for proper choroid plexus formation and function. Thus, Wt1a contributes to the barrier properties of the choroid plexus in zebrafish, revealing an unexpected role for Wt1 in the zebrafish brain

Lessons learned from the QUENCH-LOCA experiments

Seven QUENCH-LOCA bundle tests (QUENCH-L0…-L5 and -L3HT) with different cladding materials (Zry-4, M5®, Opt. ZIRLO™) were performed according to a temperature/time-scenario typical for a LBLOCA in German PWRs. For two tests (QUENCH-L4 and -L5) pre-hydrogenated claddings (with 100 and 300 wppm H for M5® and Opt. ZIRLO™, correspondingly) were used. Generally, a peak cladding temperature of about 1350 K (1250 K for QUENCH-L5) was reached at the end of the heat-up phase at the bundle elevation of 950 mm. The maximal heat-up rate was 8 K/s (2.6 K/s for commissioning test QUENCH-L0); the cooling phase lasted about 120 s (0 s for QUENCH-L0) and was terminated by 3.3 g/s/effective rod water flooding. The tangential temperature gradient across a rod was between 30 and 70 K on the burst onset. The detailed profilometry measurements performed over whole length of the claddings showed formation of not only main ballooning area (with burst) but also, for several rods of each bundle, additional two or three ballooning regions. Another parameter calculated based on profilometry measurements is the bundle blockage. The maximal coolant channel blockage was less than 35%. Due to the moderate blockage good bundle coolability was kept for all bundles. Cladding wall thinning from 725 to 350 µm due to ballooning was observed at the burst side along 50 mm below and above burst opening. The maximal oxide thickness at the outer cladding surfaces was less than 15 µm. Surface cracks, penetrating both layers, were formed in vicinity of burst opening during ballooning. Oxide layer formed after the burst at the inner cladding surface around the burst opening with a thickness of about 15 µm decreasing to 3 µm at a distance of about 20 mm from the burst opening. The hydrogen, produced during oxidation of the inner cladding surface around the burst opening, can be absorbed by the metal with formation of hydrogen enrichments around the oxidized area (secondary hydrogenation). Such enrichments with a quite complex 3D form were observed for inner rods having been exposed to peak cladding temperatures of more than 1200 K. Except for the QUENCH-L0 test, no hydrogen bands were observed for bundle outer rods, the peak cladding temperature measured for these rods was less than 1200 K. Neutron tomography analyses showed (except the QUENCH-L0 bundle with non-prototypical long duration of the transient stage and the QUENCH-L3HT with not prototypical high temperatures) that the maximal hydrogen concentrations inside the hydrogen bands was less than 750 wppm (averaged through the cladding cross section). EBSD analysis showed that a part of the hydrogen absorbed inside the claddings formed the hydrides with µm-sizes, which are distributed in the matrix intra as well inter granular. Another part of the absorbed hydrogen was probably dissolved in the metallic matrix. During quenching, following the high-temperature test stages, no fragmentation of claddings was observed meaning that the residual strengths and ductility were sufficient. Tensile tests at room temperature evidenced fracture at hydrogen bands for several inner rods with local hydrogen concentrations about 1500 wppm and more. Claddings with lower hydrogen concentrations fractured due to stress concentration at burst opening edges. Other tensile tested claddings failed after necking far away from burst region

Bispectral index versus COMFORT score to determine the level of sedation in paediatric intensive care unit patients: a prospective study

INTRODUCTION: Most clinicians give sedatives and analgesics according to their professional experience and the patient's estimated need for sedation. However, this approach is prone to error. Inadequate monitoring of sedation and analgesia may contribute to adverse outcomes and complications. With this in mind, data obtained continuously using nonstimulating methods such as bispectral index (BIS) may have benefits in comparison with clinical monitoring of sedation. The aim of this prospective observational trial was to evaluate the use of electroencephalographic (EEG) BIS for monitoring sedation in paediatric intensive care unit (PICU) patients. METHODS: Forty paediatric patients (<18 years) were sedated for mechanical ventilation in a cardiac surgical and general PICU. In each paediatric patient BIS and COMFORT score were obtained. The study protocol did not influence ongoing PICU therapy. BIS and corresponding COMFORT score were collected three times for each patient. Measurements with the best starting EEG impedances were analyzed further. Deep sedation was defined as a COMFORT score between 8 and 16, and light sedation as a score between 17 and 26. Biometric and physiological data, and Pediatric Risk of Mortality III scores were also recorded. RESULTS: There was a good correlation (Spearman's rho 0.651; P = 0.001) between BIS and COMFORT score in the presence of deep sedation and low starting impedance. Receiver operating characteristic (ROC) analysis revealed best discrimination between deep and light sedation at a BIS level of 83. CONCLUSION: In the presence of deep sedation, BIS correlated satisfactorily with COMFORT score results if low EEG impedances were guaranteed

Entwicklung eines Seminars zur Förderung des Konzeptverständnisses mittels digitaler Medien

Die Digitalisierung stellt Schule und Gesellschaft vor neue Herausforderungen, bietet jedoch gleichzeitig auch enorme Chancen. Im Physikunterricht können digitale Medien z.B. dazu beitragen, Schülerinnen und Schülern das Verständnis physikalischer Konzepte zu erleichtern. Im Rahmen des DiKoLeP-Verbundprojekts an den Universitäten Aachen, Graz und Tübingen wird daher ein Seminar entwickelt und evaluiert, dessen Ziel es ist, Studierende zum fachdidaktisch sinnvollen Einsatz von digitalen Medien zur Förderung des physikalischen Konzeptverständnisses zu befähigen. Trotz der Verankerung des Einsatzes von digitalen Medien in den KMK-Bildungsstandards haben viele Lehrkräfte nach eigenen Angaben nicht die notwendigen Kenntnisse und Erfahrungen, digitale Medien lernwirksam einzusetzen. Das neue Seminar soll daher angehenden Lehrkräften in der ersten Phase der Lehramtsausbildung die Möglichkeit geben, diese Kenntnisse und Kompetenzen zu erlangen und in komplexitätsreduzierten Unterrichtssequenzen zu erproben. Dieser Beitrag behandelt die Konzeption des Seminars und stellt die Forschungsfragen des DiKoLeP-Verbundprojekts u.a. in Zusammenhang mit der Evaluation des Seminarkonzepts vor. Zusätzlich werden die Erhebungsinstrumente und die Struktur der Evaluation dargestellt

Theory of Transmission through disordered superlattices

We derive a theory for transmission through disordered finite superlattices in which the interface roughness scattering is treated by disorder averaging. This procedure permits efficient calculation of the transmission thr ough samples with large cross-sections. These calculations can be performed utilizing either the Keldysh or the Landauer-B\"uttiker transmission formalisms, both of which yield identical equations. For energies close to the lowest miniband, we demonstrate the accuracy of the computationally efficient Wannier-function approximation. Our calculations indicate that the transmission is strongly affected by interface roughness and that information about scale and size of the imperfections can be obtained from transmission data.Comment: 12 pages, 6 Figures included into the text. Final version with minor changes. Accepted by Physical Review

Quality of Life of Patients with Head and Neck Cancer Receiving Cetuximab, Fluorouracil, Cisplatin Comparing to Cetuximab, Fluorouracil, Cisplatin, and Docetaxel within the CEFCID Trial

Introduction: CeFCiD was a multicenter phase II study comparing the efficacy of cetuximab (C), 5-flourouracil, and cisplatin with the same regimen adding docetaxel (D) in recurrent/metastatic head and neck cancer. The primary analysis trial did not demonstrate survival benefit from therapy intensification in first-line recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN). The current analysis of the trial assessed the impact of treatment on quality of life (QoL). Methods: The European Organization for Research and Treatment of Cancer Quality of life Questionnaire QLQ-C30 and the tumor-specific module for head and neck cancer (QLQ-H&N35) were used to assess QoL at baseline (visit 1), after 2 (visit 3), 4 (visit 5), and 6 (visit 7) cycles of chemotherapy. Results: Of 180 patients included in this study, 86 patients (47.8%) completed the questionnaires at baseline. Considering selected scores over treatment time, there was no difference in global QoL, dyspnea, swallowing, and speech between the treatment arms in the course. For fatigue, a significant increase from baseline to visit 3 (p = 0.02), visit 5 (p = 0.002), and to visit 7 (p = 0.003) was observed for patients receiving D, cisplatin or carboplatin (P), 5-fluorouracil (F), and C. At the end of chemotherapy, the manifestation of fatigue was similar compared in the 2 treatment arms. Discussion/Conclusion: Therapy intensification not adversely affects selected scores of QoL of patients with recurrent and/or metastatic SCCHN. Nevertheless, fatigue seems to be pronounced in patients treated with D