173 research outputs found

    Cosmic-ray propagation around the Sun: investigating the influence of the solar magnetic field on the cosmic-ray Sun shadow

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    The cosmic-ray Sun shadow, which is caused by high-energy charged cosmic rays being blocked and deflected by the Sun and its magnetic field, has been observed by various experiments, such as Argo-YBJ, HAWC, Tibet, and IceCube. Most notably, the shadow's size and depth was recently shown to correlate with the 11-year solar cycle. The interpretation of such measurements, which help to bridge the gap between solar physics and high-energy particle astrophysics, requires a solid theoretical understanding of cosmic-ray propagation in the coronal magnetic field. It is the aim of this paper to establish theoretical predictions for the cosmic-ray Sun shadow in order to identify observables that can be used to study this link in more detail. To determine the cosmic-ray Sun shadow, we numerically compute trajectories of charged cosmic rays in the energy range of 5-316 TeV for five different mass numbers. We present and analyze the resulting shadow images for protons and iron, as well as for typically measured cosmic-ray compositions. We confirm the observationally established correlation between the magnitude of the shadowing effect and both the mean sunspot number and the polarity of the magnetic field during the solar cycle. We also show that during low solar activity, the Sun's shadow behaves similarly to that of a dipole, for which we find a non-monotonous dependence on energy. In particular, the shadow can become significantly more pronounced than the geometrical disk expected for a totally unmagnetized Sun. For times of high solar activity, we instead predict the shadow to depend monotonously on energy, and to be generally weaker than the geometrical shadow for all tested energies. These effects should become visible in energy-resolved measurements of the Sun shadow, and may in the future become an independent measure for the level of disorder in the solar magnetic field.Comment: 18 pages, 88 figure

    German Index of Socioeconomic Deprivation (GISD): Revision, update and application examples

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    Background: Regional deprivation indices enable researchers to analyse associations between socioeconomic disadvantages and health outcomes even if the health data of interest does not include information on the individuals’ socioeconomic position. This article introduces the recent revision of the German Index of Socioeconomic Deprivation (GISD) and presents associations with life expectancy as well as age-standardised cardiovascular mortality rates and cancer incidences as applications. Methods: The GISD measures the level of socioeconomic deprivation using administrative data of education, employment, and income situations at the district and municipality level from the INKAR database. The indicators are weighted via principal component analyses. The regional distribution is depicted cartographically, regional level associations with health outcomes are presented. Results: The principal component analysis indicates medium to high correlations of the indicators with the index subdimensions. Correlation analyses show that in districts with the lowest deprivation, the average life expectancy of men is approximately six years longer (up to three years longer for women) than for those from districts with the highest deprivation. A similar social gradient is observed for cardiovascular mortality and lung cancer incidence. Conclusions: The GISD provides a valuable tool to analyse socioeconomic inequalities in health conditions, diseases, and their determinants at the regional level

    Brag2 differentially regulates β1- and β3-integrin-dependent adhesion in endothelial cells and is involved in developmental and pathological angiogenesis

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    β1-Integrins are essential for angiogenesis. The mechanisms regulating integrin function in endothelial cells (EC) and their contribution to angiogenesis remain elusive. Brag2 is a guanine nucleotide exchange factor for the small Arf-GTPases Arf5 and Arf6. The role of Brag2 in EC and angiogenesis and the underlying molecular mechanisms remain unclear. siRNA-mediated Brag2-silencing reduced EC angiogenic sprouting and migration. Brag2-siRNA transfection differentially affected α5β1- and αVβ3-integrin function: specifically, Brag2-silencing increased focal/fibrillar adhesions and adhesion on β1-integrin ligands (fibronectin and collagen), while reducing the adhesion on the αVβ3-integrin ligand, vitronectin. Consistent with these results, Brag2-silencing enhanced surface expression of α5β1-integrin, while reducing surface expression of αVβ3-integrin. Mechanistically, Brag2-mediated αVβ3-integrin-recycling and β1-integrin endocytosis and specifically of the active/matrix-bound α5β1-integrin present in fibrillar/focal adhesions (FA), suggesting that Brag2 contributes to the disassembly of FA via β1-integrin endocytosis. Arf5 and Arf6 are promoting downstream of Brag2 angiogenic sprouting, β1-integrin endocytosis and the regulation of FA. In vivo silencing of the Brag2-orthologues in zebrafish embryos using morpholinos perturbed vascular development. Furthermore, in vivo intravitreal injection of plasmids containing Brag2-shRNA reduced pathological ischemia-induced retinal and choroidal neovascularization. These data reveal that Brag2 is essential for developmental and pathological angiogenesis by promoting EC sprouting through regulation of adhesion by mediating β1-integrin internalization and link for the first time the process of β1-integrin endocytosis with angiogenesis.Deutsche Forschungsgemeinschaft. Transregional Collaborative Research Centre. (SFB/TR23)Deutsche Forschungsgemeinschaft. Transregional Collaborative Research Centre. (Project A2)Deutsche Forschungsgemeinschaft. Transregional Collaborative Research Centre.(Project Z5)Else Kroner-Fresenius-Stiftung (2013_A2

    I-BEAT: New ultrasonic method for single bunch measurement of ion energy distribution

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    The shape of a wave carries all information about the spatial and temporal structure of its source, given that the medium and its properties are known. Most modern imaging methods seek to utilize this nature of waves originating from Huygens' principle. We discuss the retrieval of the complete kinetic energy distribution from the acoustic trace that is recorded when a short ion bunch deposits its energy in water. This novel method, which we refer to as Ion-Bunch Energy Acoustic Tracing (I-BEAT), is a generalization of the ionoacoustic approach. Featuring compactness, simple operation, indestructibility and high dynamic ranges in energy and intensity, I-BEAT is a promising approach to meet the needs of petawatt-class laser-based ion accelerators. With its capability of completely monitoring a single, focused proton bunch with prompt readout it, is expected to have particular impact for experiments and applications using ultrashort ion bunches in high flux regimes. We demonstrate its functionality using it with two laser-driven ion sources for quantitative determination of the kinetic energy distribution of single, focused proton bunches.Comment: Paper: 17 Pages, 3 figures Supplementary Material 16 pages, 7 figure

    German Index of Socioeconomic Deprivation (GISD): Revision, Aktualisierung und Anwendungsbeispiele

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    Hintergrund: Regionale Deprivationsindizes erlauben, Zusammenhänge zwischen sozialer Benachteiligung und Gesundheit mit Daten zu analysieren, die selbst keine Information über die sozioökonomische Position der Individuen enthalten. Der vorliegende Beitrag stellt die Revision des German Index of Socioeconomic Deprivation (GISD) vor und präsentiert beispielhaft Zusammenhänge mit der Lebenserwartung sowie altersstandardisierten Herz-Kreislauf- Mortalitätsraten und Krebsinzidenzen. Methode: Der GISD misst das Ausmaß sozioökonomischer Deprivation anhand von Information der Bildungs-, Beschäftigungs- und Einkommenssituation in Kreisen und Gemeinden aus der Datenbank INKAR. Die Indikatoren werden über Hauptkomponentenanalysen gewichtet. Die regionale Verteilung wird kartografisch dargestellt, Zusammenhangsanalysen auf regionaler Ebene werden präsentiert. Ergebnisse: Die Hauptkomponentenanalysen bezeugen mittlere bis hohe Ladungen der eingesetzten Indikatoren auf den Teildimensionen des Indexes. Zusammenhangsanalysen zeigen, dass Männer in Kreisen mit der niedrigsten Deprivation eine etwa sechs Jahre, Frauen eine bis zu drei Jahre längere mittlere Lebenserwartung aufweisen als Personen aus Kreisen mit der höchsten Deprivation. Ein ähnlicher sozialer Gradient zeigt sich bei der Herz-Kreislauf- Mortalität und Lungenkrebsinzidenz. Schlussfolgerungen: Der GISD leistet einen wichtigen Beitrag zur Analyse regional ungleicher Verteilungen von Gesundheitszuständen, Krankheiten und deren Einflussfaktoren

    Thiosulfate sulfurtransferase prevents hyperglycemic damage to the zebrafish pronephros in an experimental model for diabetes

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    Thiosulfate sulfurtransferase (TST, EC 2.8.1.1), also known as Rhodanese, was initially discovered as a cyanide detoxification enzyme. However, it was recently also found to be a genetic predictor of resistance to obesity-related type 2 diabetes. Diabetes type 2 is characterized by progressive loss of adequate β-cell insulin secretion and onset of insulin resistance with increased insulin demand, which contributes to the development of hyperglycemia. Diabetic complications have been replicated in adult hyperglycemic zebrafish, including retinopathy, nephropathy, impaired wound healing, metabolic memory, and sensory axonal degeneration. Pancreatic and duodenal homeobox 1 (Pdx1) is a key component in pancreas development and mature beta cell function and survival. Pdx1 knockdown or knockout in zebrafish induces hyperglycemia and is accompanied by organ alterations similar to clinical diabetic retinopathy and diabetic nephropathy. Here we show that pdx1-knockdown zebrafish embryos and larvae survived after incubation with thiosulfate and no obvious morphological alterations were observed. Importantly, incubation with hTST and thiosulfate rescued the hyperglycemic phenotype in pdx1-knockdown zebrafish pronephros. Activation of the mitochondrial TST pathway might be a promising option for therapeutic intervention in diabetes and its organ complications

    HICFD – Highly Efficient Implementation of CFD Codes for HPC Many-Core Architectures

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    The objective of the German BMBF research project Highly Efficient Implementation of CFD Codes for HPC Many-Core Architectures (HICFD) is to develop new methods and tools for the analysis and optimization of the performance of parallel computational fluid dynamics (CFD) codes on high performance computer systems with many-core processors. In the work packages of the project it is investigated how the performance of parallel CFD codes written in C can be increased by the optimal use of all parallelism levels. On the highest level MPI is utilized. Furthermore, on the level of the many-core architecture, highly scaling, hybrid OpenMP/MPI methods are implemented. On the level of the processor cores the parallel SIMD units provided by modern CPUs are exploited

    New technical approach for the repair of an abdominal wall defect after a transverse rectus abdominis myocutaneous flap: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Breast reconstruction with autologous tissue transfer is now a standard operation, but abnormalities of the abdominal wall contour represent a complication which has led surgeons to invent techniques to minimize the morbidity of the donor site.</p> <p>Case presentation</p> <p>We report the case of a woman who had bilateral transverse rectus abdominis myocutaneous flap (TRAM-flap) breast reconstruction. The surgery led to the patient developing an enormous abdominal bulge that caused her disability in terms of abdominal wall and bowel function, pain and contour. In the absence of rectus muscle, the large defect was repaired using a combination of the abdominal wall component separation technique of Ramirez et al and additional mesh augmentation with a lightweight, large-pore polypropylene mesh (Ultrapro<sup>®</sup>).</p> <p>Conclusion</p> <p>The procedure of Ramirez et al is helpful in achieving a tension-free closure of large defects in the anterior abdominal wall. The additional mesh augmentation allows reinforcement of the thinned lateral abdominal wall.</p

    I-BEAT: Ultrasonic method for online measurement of the energy distribution of a single ion bunch

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    The shape of a wave carries all information about the spatial and temporal structure of its source, given that the medium and its properties are known. Most modern imaging methods seek to utilize this nature of waves originating from Huygens' principle. We discuss the retrieval of the complete kinetic energy distribution from the acoustic trace that is recorded when a short ion bunch deposits its energy in water. This novel method, which we refer to as Ion-Bunch Energy Acoustic Tracing (I-BEAT), is a refinement of the ionoacoustic approach. With its capability of completely monitoring a single, focused proton bunch with prompt readout and high repetition rate, I-BEAT is a promising approach to meet future requirements of experiments and applications in the field of laser-based ion acceleration. We demonstrate its functionality at two laser-driven ion sources for quantitative online determination of the kinetic energy distribution in the focus of single proton bunches
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