1,100 research outputs found

    Discovery of the VHE gamma-ray source HESS J1641-463

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    A new TeV source, HESS J1641-463, has been serendipitously discovered in the Galactic plane by the High Energy Stereoscopic System (H.E.S.S.) at a significance level of 8.6 standard deviations. The observations of HESS J1641-463 were performed between 2004 and 2011 and the source has a moderate flux level of 1.7% of the Crab Nebula flux at E > 1 TeV. HESS J1641-463 has a rather hard photon index of 1.99 +- 0.13_stat +- 0.20_sys. HESS J1641-463 is positionally coincident with the radio supernova remnant SNR G338.5+0.1, but no clear X-ray counterpart has been found in archival Chandra observations of the region. Different possible VHE production scenarios will be discussed in this contribution.Comment: 5 pages, 5 figures, 2012 Fermi Symposium proceedings - eConf C12102

    Thermo-visual feature fusion for object tracking using multiple spatiogram trackers

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    In this paper, we propose a framework that can efficiently combine features for robust tracking based on fusing the outputs of multiple spatiogram trackers. This is achieved without the exponential increase in storage and processing that other multimodal tracking approaches suffer from. The framework allows the features to be split arbitrarily between the trackers, as well as providing the flexibility to add, remove or dynamically weight features. We derive a mean-shift type algorithm for the framework that allows efficient object tracking with very low computational overhead. We especially target the fusion of thermal infrared and visible spectrum features as the most useful features for automated surveillance applications. Results are shown on multimodal video sequences clearly illustrating the benefits of combining multiple features using our framework

    Comparative solution and structural studies of half-sandwich rhodium and ruthenium complexes bearing curcumin and acetylacetone

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    Half-sandwich organometallic complexes of curcumin are extensively investigated as anticancer compounds.Speciation studies were performed to explore the solution stability of curcumin complexes formed with [Rh(η5- C5Me5)(H2O)3]2+. Acetylacetone (Hacac), as the simplest ÎČ-diketone ligand bearing (O,O) donor set, was involved for comparison and its Ru(η6‑p‑cymene), Ru(η6‑toluene) complexes were also studied. 1H NMR, UV–visible and pH-potentiometric titrations revealed a clear trend of stability constants of the acac complexes: Ru(η6‑p‑cymene) > Ru(η6‑toluene) > Rh(η5-C5Me5). Despite this order, the highest extent of complex formation is seen for the Rh(η5-C5Me5) complexes at pH 7.4. Formation constant of [Rh(η5-C5Me5)(H2curcumin) (H2O)]+ reveals similar solution stability to that of the acac complex. Additionally, structures of two complexes were determined by X-ray crystallography. The in vitro cytotoxicity of curcumin was not improved by the complexation with these organometallic cations.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/2875]This is the peer-reviewed version of the following article: Meszaros, J. P.; Poljarević, J.; Gal, T. G.; May, N. V.; Spengler, G.; Enyedy, E. A. Comparative Solution and Structural Studies of Half-Sandwich Rhodium and Ruthenium Complexes Bearing Curcumin and Acetylacetone. Journal of Inorganic Biochemistry 2019, 195, 91–100. [https://doi.org/10.1016/j.jinorgbio.2019.02.015

    Heisenberg's Uncertainty Relation and Bell Inequalities in High Energy Physics

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    An effective formalism is developed to handle decaying two-state systems. Herewith, observables of such systems can be described by a single operator in the Heisenberg picture. This allows for using the usual framework in quantum information theory and, hence, to enlighten the quantum feature of such systems compared to non-decaying systems. We apply it to systems in high energy physics, i.e. to oscillating meson-antimeson systems. In particular, we discuss the entropic Heisenberg uncertainty relation for observables measured at different times at accelerator facilities including the effect of CP violation, i.e. the imbalance of matter and antimatter. An operator-form of Bell inequalities for systems in high energy physics is presented, i.e. a Bell-witness operator, which allows for simple analysis of unstable systems.Comment: 17 page

    Molecular Characterization of the Gastrula in the Turtle Emys orbicularis: An Evolutionary Perspective on Gastrulation

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    Due to the presence of a blastopore as in amphibians, the turtle has been suggested to exemplify a transition form from an amphibian- to an avian-type gastrulation pattern. In order to test this hypothesis and gain insight into the emergence of the unique characteristics of amniotes during gastrulation, we have performed the first molecular characterization of the gastrula in a reptile, the turtle Emys orbicularis. The study of Brachyury, Lim1, Otx2 and Otx5 expression patterns points to a highly conserved dynamic of expression with amniote model organisms and makes it possible to identify the site of mesoderm internalization, which is a long-standing issue in reptiles. Analysis of Brachyury expression also highlights the presence of two distinct phases, less easily recognizable in model organisms and respectively characterized by an early ring-shaped and a later bilateral symmetrical territory. Systematic comparisons with tetrapod model organisms lead to new insights into the relationships of the blastopore/blastoporal plate system shared by all reptiles, with the blastopore of amphibians and the primitive streak of birds and mammals. The biphasic Brachyury expression pattern is also consistent with recent models of emergence of bilateral symmetry, which raises the question of its evolutionary significance

    Condensation of water vapor in the gravitational field

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    Physical peculiarities of water vapor condensation under conditions of hydrostatic equilibrium are considered. The power of stationary dynamic air fluxes and the vertical temperature distribution caused by condensation on large horizontal scales are estimated.Comment: 10 p
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