Financial crises and information transfer: An empirical analysis of the lead-lag relationship between equity and CDS iTraxx Indices

This study examines the lead-lag-relationship between European equity and CDS markets in the context of the financial crisis. Previous research identified the stock market to lead the CDS market in an ordinary economic environment. Against the background of our study this lead-lag-relationship strengthens when moving from the non-crisis- to the crisisscenario on a daily as well as on a weekly basis. Hence, we conclude that information transfer from stock to CDS markets widens during the financial crisis. In addition and in contrast to the literature we find an extraordinary day-of-the-week-effect on weekly returns as an anomaly for information processing. --Granger-causality, iTraxx Indices, Credit Default Swaps, Day-of-the-Week-Effect, Feedback System

Selective blockade of inhibitory Fcγ receptor enables human dendritic cell maturation with IL-12p70 production and immunity to antibody-coated tumor cells

he final differentiation or maturation of dendritic cells (DCs) in response to environmental stimuli influences their ability to both initiate immunity and determine the quality of the response to antigens. Circulating immune complexes and cell-bound immunoglobulins present in normal human sera represent a potential stimulus for inadvertent DC activation in the steady state and during autoimmunity. Here, we show that selective blockade of the inhibitory Fcγ receptor (FcγR) FcγRIIb with recently developed monoclonal antibodies leads to maturation of human monocyte-derived DCs, which depends on the presence of IgG in normal human plasma. Plasma, in the presence of an FcγRIIb blockade, caused the DCs to up-regulate the expression of costimulatory molecules and to produce the inflammatory mediator IL-12p70. FcγRIIb blockade of DCs loaded with tumor cells led to increased tumor-specific T cell immunity without the need for exogenous stimuli other than human plasma. Therefore, the activation status of DCs in the presence of normal human serum depends on the balance between activating and inhibitory FcγRs and can be enhanced by new antibodies that react selectively with FcγRIIb. These data suggest an approach for modifying this balance to enhance immunity to immune complexes and antibody-coated tumor cells and to silence DC activation by immune complexes in autoimmune states. © 2005 by The National Academy of Sciences of the USA

Clinical skills of veterinary students - a cross-sectional study of the self-concept and exposure to skills training in Hannover, Germany

Background: Students of veterinary medicine should achieve basic professional competences required to practise their profession. A main focus of veterinary education is on developing clinical skills. The present study used the guidelines of the "Day-One Skills" list of European Association of Establishments for Veterinary Education (EAEVE) to create an online questionnaire for assessing the skills acquired by students at the University of Veterinary Medicine Hannover (TiHo). The theoretical and practical veterinary knowledge levels of the students and postgraduates are determined and compared. Results: In two batches, 607 people responded (response batch 1, 23.78%; response batch 2, 23.83%). From 49 defined skills, 28 are actually practised during training at the university and 21 activities are known only theoretically. Furthermore, the students showed great willingness to use simulators and models in a clinical skills lab. Conclusions: The results of this survey highlight that the opening of a clinical skills lab at the University of Veterinary Medicine Hannover and its incorporation into the study programme are ideal tools to promote practical competences and foster the motivation to learn

TLR9/MyD88 signaling is required for class switching to pathogenic IgG2a and 2b autoantibodies in SLE

Loss of tolerance in systemic lupus erythematosus (SLE) leads to the generation of autoantibodies, which accumulate in end-organs where they induce disease. Here we show that immunoglobulin (Ig)G2a and 2b autoantibodies are the pathogenic isotypes by recruiting FcγRIV expressing macrophages. Class switching, but not development, of IgM anti-self B cells to these pathogenic subclasses requires the innate immune receptor Toll-like receptor (TLR)9 and MyD88 signaling. In their absence, switching of autoreactive B cells to the IgG2a and 2b subclasses is blocked, resulting in reduced pathology and mortality. In contrast, switching of anti-self B cells to IgG1 is not perturbed and generation of nonautoreactive IgG2a and 2b antibodies is not impaired in TLR9-deficient mice. Thus, the TLR9 pathway is a potential target for therapeutic intervention in SLE

Duality in linearized gravity

We show that duality transformations of linearized gravity in four dimensions, i.e., rotations of the linearized Riemann tensor and its dual into each other, can be extended to the dynamical fields of the theory so as to be symmetries of the action and not just symmetries of the equations of motion. Our approach relies on the introduction of two "superpotentials", one for the spatial components of the spin-2 field and the other for their canonically conjugate momenta. These superpotentials are two-index, symmetric tensors. They can be taken to be the basic dynamical fields and appear locally in the action. They are simply rotated into each other under duality. In terms of the superpotentials, the canonical generator of duality rotations is found to have a Chern-Simons like structure, as in the Maxwell case.Comment: 10 pages; introduction rewritten and references adde

G_2 Perfect-Fluid Cosmologies with a proper conformal Killing vector

We study the Einstein field equations for spacetimes admitting a maximal two-dimensional abelian group of isometries acting orthogonally transitively on spacelike surfaces and, in addition, with at least one conformal Killing vector. The three-dimensional conformal group is restricted to the case when the two-dimensional abelian isometry subalgebra is an ideal and it is also assumed to act on non-null hypersurfaces (both, spacelike and timelike cases are studied). We consider both, diagonal and non-diagonal metrics and find all the perfect-fluid solutions under these assumptions (except those already known). We find four families of solutions, each one containing arbitrary parameters for which no differential equations remain to be integrated. We write the line-elements in a simplified form and perform a detailed study for each of these solutions, giving the kinematical quantities of the fluid velocity vector, the energy-density and pressure, values of the parameters for which the energy conditions are fulfilled everywhere, the Petrov type, the singularities in the spacetimes and the Friedmann-Lemaitre-Robertson-Walker metrics contained in each family.Comment: Latex, no figure

Erfahrungen aus Entwicklung und Einsatz eines interdisziplinären Blended-Learning-Wahlpflichtfachs an zwei tiermedizinischen Hochschulen

Seit 2007 treffen sich die acht deutschsprachigen, tiermedizinischen Bildungsstätten regelmäßig zu E-Learning-Symposien, um einen Austausch von Lernmaterialien vorzubereiten und Synergien auf diesem Gebiet zu nutzen. In Spezialfächern, die nicht an allen Universitäten mit einem Lehrstuhl besetzt werden können, wäre E-Learning eine ideale Ergänzung zum Präsenzunterricht. Als Pilotprojekt wurde daher ein gemeinsames Wahlpflichtfach „Neuroimmunologie“ zwischen der Vetsuisse-Fakultät Universität Bern und der Stiftung Tierärztliche Hochschule Hannover verabredet. Hiermit konnte gezeigt werden, dass eine Zusammenarbeit mehrerer Universitäten und verschiedener Disziplinen möglich ist, um Kurse zu erstellen und durchzuführen, und dass die Akzeptanz dieser Kurse bei den Studierenden hoch ist. 24.06.2010 | Michael Koch (Hannover), Martin R. Fischer (Witten-Herdecke), Marc Vandevelde (Bern), Andrea Tipold (Hannover) & Jan P. Ehlers (Hannover

Genome-wide scan for self-rating of the effects of alcohol (SRE) in American Indians

This study’s aims were to map loci linked to self-rating of the effects of alcohol and to determine if there was overlap with loci previously mapped for other substance dependence phenotypes in an American Indian community at high risk for substance dependence

Hidden Symmetries and Dirac Fermions

In this paper, two things are done. First, we analyze the compatibility of Dirac fermions with the hidden duality symmetries which appear in the toroidal compactification of gravitational theories down to three spacetime dimensions. We show that the Pauli couplings to the p-forms can be adjusted, for all simple (split) groups, so that the fermions transform in a representation of the maximal compact subgroup of the duality group G in three dimensions. Second, we investigate how the Dirac fermions fit in the conjectured hidden overextended symmetry G++. We show compatibility with this symmetry up to the same level as in the pure bosonic case. We also investigate the BKL behaviour of the Einstein-Dirac-p-form systems and provide a group theoretical interpretation of the Belinskii-Khalatnikov result that the Dirac field removes chaos.Comment: 30 page

ReluDiff: Differential Verification of Deep Neural Networks

As deep neural networks are increasingly being deployed in practice, their efficiency has become an important issue. While there are compression techniques for reducing the network's size, energy consumption and computational requirement, they only demonstrate empirically that there is no loss of accuracy, but lack formal guarantees of the compressed network, e.g., in the presence of adversarial examples. Existing verification techniques such as Reluplex, ReluVal, and DeepPoly provide formal guarantees, but they are designed for analyzing a single network instead of the relationship between two networks. To fill the gap, we develop a new method for differential verification of two closely related networks. Our method consists of a fast but approximate forward interval analysis pass followed by a backward pass that iteratively refines the approximation until the desired property is verified. We have two main innovations. During the forward pass, we exploit structural and behavioral similarities of the two networks to more accurately bound the difference between the output neurons of the two networks. Then in the backward pass, we leverage the gradient differences to more accurately compute the most beneficial refinement. Our experiments show that, compared to state-of-the-art verification tools, our method can achieve orders-of-magnitude speedup and prove many more properties than existing tools.Comment: Extended version of ICSE 2020 paper. This version includes an appendix with proofs for some of the content in section 4.