1,291 research outputs found

    Emergent inert adjoint scalar field in SU(2) Yang-Mills thermodynamics due to coarse-grained topological fluctuation

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    We compute the phase and the modulus of an energy- and pressure-free, composite, adjoint, and inert field φ in an SU(2) Yang-Mills theory at large temperatures. This field is physically relevant in describing part of the ground-state structure and the quasiparticle masses of excitations. The field φ possesses nontrivial S1-winding on the group manifold S3. Even at asymptotically high temperatures, where the theory reaches its Stefan-Boltzmann limit, the field φ, though strongly power suppressed, is conceptually relevant: its presence resolves the infrared problem of thermal perturbation theory

    Possibility of detecting density isomers in high-density nuclear mach shock waves

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    Up to now no experimentally feasible method for detecting abnormal nuclear states has been known. We propose to observe them in high-energy heavy-ion collisions through the disappearance of, or irregularities in, high-density nuclear Mach shock phenomena

    Antibodies aggravate the development of ischemic heart failure

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    Heart-specific antibodies have been widely associated with myocardial infarction (MI). However, it remains unclear whether autoantibodies mediate disease progression or are a byproduct of cardiac injury. To disambiguate the role of immunoglobulins in MI, we characterized the development of ischemic heart failure in agammaglobulinemic mice (AID-/-μS-/-). Although these animals can produce functional B cells, they cannot synthesize secretory IgM (μS-/-) or perform Ig class switching (AID-/-), leading to complete antibody deficiency. Agammaglobulinemia did not affect overall post-MI survival but resulted in a significant reduction in infarct size. Echocardiographic analyses showed that, compared with wild-type infarcted control mice, AID-/-μS-/- mice exhibited improved cardiac function and reduced remodeling on day 56 post-MI. These differences remained significant even after animals with matched infarct sizes were compared. Infarcted AID-/-μS-/- mice also showed reduced myocardial expression levels of transcripts known to promote adverse remodeling, such as matrix metalloproteinase-9, collagen type I a1, collagen type III a1, and IL-6. An unbiased screening of the heart reactivity potential in the plasma of wild-type MI animals revealed the presence of antibodies that target the myocardial scar and collagenase-sensitive epitopes. Moreover, we found that IgG accumulated within the scar tissues of infarcted mice and remained in close proximity with cells expressing Fcγ receptors (CD16/32), suggesting the existence of an in situ IgG-Fcγ receptor axis. Collectively, our study results confirm that antibodies contribute to ischemic heart failure progression and provide novel insights into the mechanisms underlying this phenomenon. NEW & NOTEWORTHY Our study sheds some light on the long-standing debate over the relevance of autoantibodies in heart failure and might stimulate future research in the field. The observation of extracellular matrix-specific antibodies and the detection of Fcγ receptor-expressing cells within the scar provide novel insights into the mechanisms by which antibodies may contribute to adverse remodeling.info:eu-repo/semantics/publishedVersio

    Production and Function of Serotonin in Cardiac Cells

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    Serotonin [5-hydroxy-tryptamine (5-HT)] exerts a number of effects in the mammalian heart: increase in heart rate, increase in force of contraction, fibrosis of cardiac valves, coronary constriction, arrhythmias and thrombosis. These effects are, in part, mediated by 5-HT-receptors, in part, directly by 5-HT action on intracellular proteins. In the beginning, 5-HT was thought to be only produced in the gut and then transported into the heart via platelets, because platelets can take up 5-HT in the gut and enter the capillaries and thus the mammalian heart. 5-HT is to a large extent metabolized in the liver and excreted via the urine. Here, we will also overview data that argue for additional pathways, namely production and degradation of 5-HT in the cells of the heart itself

    Improved energy resolution for VHE gamma-ray astronomy with systems of Cherenkov telescopes

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    We present analysis techniques to improve the energy resolution of stereoscopic systems of imaging atmospheric Cherenkov telescopes, using the HEGRA telescope system as an example. The techniques include (i) the determination of the height of the shower maximum, which is then taken into account in the energy determination, and (ii) the determination of the location of the shower core with the additional constraint that the direction of the gamma rays is known a priori. This constraint can be applied for gamma-ray point sources, and results in a significant improvement in the localization of the shower core, which translates into better energy resolution. Combining both techniques, the HEGRA telescopes reach an energy resolution between 9% and 12%, over the entire energy range from 1 TeV to almost 100 TeV. Options for further improvements of the energy resolution are discussed.Comment: 13 Pages, 7 figures, Latex. Astroparticle Physics, in pres
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