Top-Antitop-Quark Production and Decay Properties at the Tevatron

At the Tevatron, the collider experiments CDF and DO have data sets at their disposal that comprise a few thousand reconstructed top-antitop-quark pairs and allow for precision measurements of the cross section as well as production and decay properties. Besides comparing the measurements to standard model predictions, these data sets open a window to physics beyond the standard model. Dedicated analyses look for new heavy gauge bosons, fourth generation quarks, and flavor-changing neutral currents. In this mini-review the current status of these measurements is summarized.Comment: Mini-review to be submitted to Mod. Phys. Lett. A, was derived from the proceedings of the 21st Rencontres de Blois: Windows on the Universe, Blois, France, 21. - 27. June 2009. 19 pages. 2nd revision: correct a few minor mistakes, update references

Wie einfach kann ein Steuersystem sein?

Wie sollte ein zukünftiges Steuersystem aufgebaut sein? Wie einfach kann es sein? Für Prof. Dr. Hans-Wolfgang Arndt, Universität Mannheim, ist der Karlsruher Entwurf für das Einkommensteuerrecht mustergültig. Prof. Dr. Dr. h.c. Franz W. Wagner, Universität Tübingen, sieht das größte Defizit der Diskussion um eine Steuervereinfachung darin, »dass den Bürgern verschwiegen wird, dass stark vereinfachte Steuersysteme die bisherigen Umverteilungs- und Anreizfunktionen des Steuersystems nicht übernehmen können... Würden die Bürger hingegen darüber informiert, dass tiefgreifende Eingriffe in Anreiz- und Verteilungsmechanismen das eigentliche Problem jeder Steuerreform sind, würde das Schlagwort der Steuervereinfachung seine konsensmobilisierende Funktion vermutlich schnell einbüßen.« Friedrich Merz, CDU/CSU-Fraktion, sieht das Ziel einer Vereinfachung des Steuerrechts in der »Wiederherstellung der Verständlichkeit. Ein verständliches und für Steuerpflichtige und Steuerverwaltung nachvollziehbares Steuerrecht schafft Akzeptanz und Rechtssicherheit.

Wie einfach kann ein Steuersystem sein?

Wie sollte ein zukünftiges Steuersystem aufgebaut sein? Wie einfach kann es sein? Für Prof. Dr. Hans-Wolfgang Arndt, Universität Mannheim, ist der Karlsruher Entwurf für das Einkommensteuerrecht mustergültig. Prof. Dr. Dr. h.c. Franz W. Wagner, Universität Tübingen, sieht das größte Defizit der Diskussion um eine Steuervereinfachung darin, »dass den Bürgern verschwiegen wird, dass stark vereinfachte Steuersysteme die bisherigen Umverteilungs- und Anreizfunktionen des Steuersystems nicht übernehmen können... Würden die Bürger hingegen darüber informiert, dass tiefgreifende Eingriffe in Anreiz- und Verteilungsmechanismen das eigentliche Problem jeder Steuerreform sind, würde das Schlagwort der Steuervereinfachung seine konsensmobilisierende Funktion vermutlich schnell einbüßen.« Friedrich Merz, CDU/CSU-Fraktion, sieht das Ziel einer Vereinfachung des Steuerrechts in der »Wiederherstellung der Verständlichkeit. Ein verständliches und für Steuerpflichtige und Steuerverwaltung nachvollziehbares Steuerrecht schafft Akzeptanz und Rechtssicherheit.«Steuerreform, Steuersystem, Steuervereinfachung, Deutschland

08271 Abstracts Collection -- Topological and Game-Theoretic Aspects of Infinite Computations

From June 29, 2008, to July 4, 2008, the Dagstuhl Seminar 08271 ``Topological and Game-Theoretic Aspects of Infinite Computations\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, many participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

Novel Schizophrenia Risk Gene TCF4 Influences Verbal Learning and Memory Functioning in Schizophrenia Patients

Background: Recently, a role of the transcription factor 4 (TCF4) gene in schizophrenia has been reported in a large genome-wide association study. It has been hypothesized that TCF4 affects normal brain development and TCF4 has been related to different forms of neurodevelopmental disorders. Schizophrenia patients exhibit strong impairments of verbal declarative memory (VDM) functions. Thus, we hypothesized that the disease-associated C allele of the rs9960767 polymorphism of the TCF4 gene led to impaired VDM functioning in schizophrenia patients. Method: The TCF4 variant was genotyped in 401 schizophrenia patients. VDM functioning was measured using the Rey Auditory Verbal Learning Test (RAVLT). Results: Carriers of the C allele were less impaired in recognition compared to those carrying the AA genotype (13.76 vs. 13.06; p = 0.049). Moreover, a trend toward higher scores in patients with the risk allele was found for delayed recall (10.24 vs. 9.41; p = 0.088). The TCF4 genotype did not influence intelligence or RAVLT immediate recall or total verbal learning. Conclusion: VDM function is influenced by the TCF4 gene in schizophrenia patients. However, the elevated risk for schizophrenia is not conferred by TCF4-mediated VDM impairment. Copyright (C) 2011 S. Karger AG, Base

Physical activity specifically evokes release of cell-free DNA from granulocytes thereby affecting liquid biopsy

Physical activity impacts immune homeostasis and leads to rapid and marked increase in cell-free DNA (cfDNA). However, the origin of cfDNA during exercise remains elusive and it is unknown if physical activity could improve or interfere with methylation based liquid biopsy. We analyzed the methylation levels of four validated CpGs representing cfDNA from granulocytes, lymphocytes, monocytes, and non-hematopoietic cells, in healthy individuals in response to exercise, and in patients with hematological malignancies under resting conditions. The analysis revealed that physical activity almost exclusively triggered DNA release from granulocytes, highlighting the relevance as a pre-analytical variable which could compromise diagnostic accuracy

Association between Antibodies to the MR 67,000 Isoform of Glutamate Decarboxylase (GAD) and Type 1 (Insulin-Dependent) Diabetes Mellitus with Coexisting Autoimmune Polyendocrine Syndrome Type II

By using an immunoprecipitation assay, we analysed reactivity of autoantibodies to human recombinant GAD65 and GAD67 in sera from patients with autoimmune polyendocrine syndrome Type II (APS II) with and without Type 1 (insulin-dependent) diabetes mellitus (IDDM) compared to patients with organ-specific autoimmunity. Overall antibodies to GAD65 were correlated with IDDM in all study groups, whereas GAD67 antibodies were associated with IDDM when APS II coexists. Antibodies to GAD65 and GAD67 were detected in 13 (44.8%) and 7 (24.1%) out of 29 APS II patients with IDDM, but in only 4 (13.8%) and 2 (6.9%) out of 29 APS II patients without IDDM, respectively (p < 0.05). In short-standing IDDM (< 1 year), antibodies to GAD67 were significantly more frequent in patients with APS II (5 of 9 [55.6%] subjects) compared to matched diabetic patients without coexisting polyendocrinopathy (1 of 18 [5.6%] subjects) (p < 0.02). The levels of GAD65 (142 ± 90 AU) and GAD67 antibodies (178 ± 95 AU) were significantly higher in patients with polyglandular disease than in patients with isolated IDDM (91 ± 85 AU and 93 ± 57 AU) (p < 0.02). Interestingly, all 11 GAD67 antibody positive subjects also had GAD65 antibodies (p < 0.0001), and in 10 of 11 anti-GAD67 positive sera the GAD67 antibodies could be blocked by either GAD67 or GAD65, suggesting the presence of cross-reactive autoantibodies. No correlation was observed between GAD antibodies and age, sex or any particular associated autoimmune disease, besides IDDM. GAD antibodies were present in only 1 of 6 (16.7%) patients with APS Type I, in 1 of 26 (3.9%) patients with autoimmune thyroid disease but in none of the patients with Addison's disease (n = 16), pernicious anaemia (n = 7) or normal controls (n = 50). Our data suggest distinct antibody specificities reactive to GAD isoforms in APS II and IDDM, which might reflect different mechanisms of autoimmune response in IDDM with coexisting autoimmune polyendocrine autoimmunity