1,657 research outputs found

    Frankreichs Sicherheits- und Verteidigungspolitik ohne Strategie: deutsch-französische Initiativen anstelle eines französischen Aktionismus

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    Die französischen Streitkräfte sind derzeit sehr gefragt: Im Kampf gegen die Terrorgruppe Islamischer Staat (IS) wird Paris in den kommenden Wochen sechs Mirage-Kampfflugzeuge nach Jordanien verlegen. Am 1. August 2014 hat Frankreich die Antiterror-Operation Barkhane (Sicheldüne) im Sahel- und Sahararaum begonnen. 3000 Soldatinnen und Soldaten sind mit schwerem Gerät von Mali und Tschad, ab 2015 auch von Niger aus im Einsatz. In der Ukraine will die französische Regierung Aufklärungsdrohnen verwenden, Spionageboote der Marine patrouillieren bereits im Schwarzen Meer. Dass die Armee jeden Krisenherd der Welt bearbeiten kann, erweist sich indes zusehends als Irrglaube. Frankreichs Streitkräfte, so beklagen ranghohe Militärs, "gehen auf dem Zahnfleisch". Längst reichen Personalreduzierungen und Standortschließungen nicht mehr aus, um die überfällige Modernisierung der Ausrüstung zu finanzieren. Deutsch-französische Initiativen in der Gemeinsamen Sicherheits- und Verteidigungspolitik (GSVP) könnten Frankreichs Sicherheits- und Verteidigungspolitik wieder schärfere Konturen verleihen. (Autorenreferat

    Kinetics and protective role of autophagy in a mouse cecal ligation and puncture-induced sepsis

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    INTRODUCTION: It is not well understood whether the process of autophagy is accelerated or blocked in sepsis, and whether it is beneficial or harmful to the immune defense mechanism over a time course during sepsis. Our aim was to determine both the kinetics and the role of autophagy in sepsis. METHODS: We examined autophagosome and autolysosome formation in a cecal ligation and puncture (CLP) mouse model of sepsis (in C57BL/6N mice and GFP-LC3 transgenic mice), using western blotting, immunofluorescence, and electron microscopy. We also investigated the effect of chloroquine inhibition of autophagy on these processes. RESULTS: Autophagy, as demonstrated by increased LC3-II/LC3-I ratios, is induced in the liver, heart, and spleen over 24 h after CLP. In the liver, autophagosome formation peaks at 6 h and declines by 24 h. Immunofluorescent localization of GFP-LC3 dots (alone and with lysosome-associated membrane protein type 1 (LAMP1)), as well as electron microscopic examination, demonstrate that both autophagosomes and autolysosomes are increased after CLP, suggesting that intact autophagy mechanisms operate in the liver in this model. Furthermore, inhibition of autophagy process by chloroquine administration immediately after CLP resulted in elevated serum transaminase levels and a significant increase in mortality. CONCLUSIONS: All autophagy-related processes are properly activated in the liver in a mouse model of sepsis; autophagy appears to play a protective role in septic animals

    The Erotic and the Vulgar: Visual Culture and Organized Labor's Critique of U.S. Hegemony in Occupied Japan

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    This essay engages the colonial legacy of postwar Japan by arguing that the political cartoons produced as part of the postwar Japanese labor movement’s critique of U.S. cultural hegemony illustrate how gendered discourses underpinned, and sometimes undermined, the ideologies formally represented by visual artists and the organizations that funded them. A significant component of organized labor’s propaganda rested on a corpus of visual media that depicted women as icons of Japanese national culture. Japan’s most militant labor unions were propagating anti-imperialist discourses that invoked an engendered/endangered nation that accentuated the importance of union roles for men by subordinating, then eliminating, union roles for women

    Spectroscopy of a single-carrier bilayer graphene quantum dot from time-resolved charge detection

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    We measured the spectrum of a single-carrier bilayer graphene quantum dot as a function of both parallel and perpendicular magnetic fields, using a time-resolved charge detection technique that gives access to individual tunnel events. Thanks to our unprecedented energy resolution of 4μ \mu~eV, we could distinguish all four levels of the dot's first orbital, in particular in the range of magnetic fields where the first and second excited states cross (B100 B_\perp\lesssim 100~mT). We thereby experimentally establish, the hitherto extrapolated, single-charge carrier spectrum picture and provide a new upper bound for the inter-valley mixing, equal to our energy resolution

    Modest antiviral activity of Toll-like receptor 3 (TLR3) against

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    Human respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infections in infants and Toll-like receptors (TLRs) are the first line of host defense against such infections. In this study, we aimed to elucidate the antiviral effect of TLR3 against RSV infection. The human TLR3 gene was either transiently or stably overexpressed in A549 cells and they were infected with the Long strain of RSV. In both cases, RSV production determined by plaque assay was modestly but significantly decreased in the TLR3-overexpressed cells compared with control cells. Less interferon (IFN)-β, measured by ELISA, was produced in the supernatant of the TLR3- overexpressed cells. Neutralization of IFN-β in the supernatant of the TLR3-overexpressed cells failed to increase RSV production to the same level as controls. These results indicate that TLR3 has modest anti-RSV activity and IFN-β seems not to be a significant mediator of this activity

    Dipole coupling of a bilayer graphene quantum dot to a high-impedance microwave resonator

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    We implement circuit quantum electrodynamics (cQED) with quantum dots in bilayer graphene, a maturing material platform for semiconductor qubits that can host long-lived spin and valley states. The presented device combines a high-impedance (Zr1kΩZ_\mathrm{r} \approx 1 \mathrm{k{\Omega}}) superconducting microwave resonator with a double quantum dot electrostatically defined in a graphene-based van der Waals heterostructure. Electric dipole coupling between the subsystems allows the resonator to sense the electric susceptibility of the double quantum dot from which we reconstruct its charge stability diagram. We achieve sensitive and fast detection with a signal-to-noise ratio of 3.5 within 1 μs{\mu}\mathrm{s} integration time. The charge-photon interaction is quantified in the dispersive and resonant regimes by comparing the coupling-induced change in the resonator response to input-output theory, yielding a maximal coupling strength of g/2π=49.7MHzg/2{\pi} = 49.7 \mathrm{MHz}. Our results introduce cQED as a probe for quantum dots in van der Waals materials and indicate a path toward coherent charge-photon coupling with bilayer graphene quantum dots.Comment: 9 pages, 4 figure

    Nanoscale mapping and spectroscopy of non-radiative hyperbolic modes in hexagonal boron nitride nanostructures

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    The inherent crystal anisotropy of hexagonal boron nitride (hBN) sustains naturally hyperbolic phonon polaritons, i.e. polaritons that can propagate with very large wavevectors within the material volume, thereby enabling optical confinement to exceedingly small dimensions. Indeed, previous research has shown that nanometer-scale truncated nanocone hBN cavities, with deep subwavelength dimensions, support three-dimensionally confined optical modes in the mid-infrared. Due to optical selection rules, only a few of many such modes predicted theoretically have been observed experimentally via far-field reflection and scattering-type scanning near-field optical microscopy. The Photothermal induced resonance (PTIR) technique probes optical and vibrational resonances overcoming weak far-field emission by leveraging an atomic force microscope (AFM) probe to transduce local sample expansion due to light absorption. Here we show that PTIR enables the direct observation of previously unobserved, dark hyperbolic modes of hBN nanostructures. Leveraging these optical modes could yield a new degree of control over the electromagnetic near-field concentration, polarization and angular momentum in nanophotonic applications.Comment: 14 pages with references, 4 figure

    Exploring the ecology of deep-sea hydrothermal vents in a metacommunity framework

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    © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Marine Science 5 (2018): 49, doi:10.3389/fmars.2018.00049.Species inhabiting deep-sea hydrothermal vents are strongly influenced by the geological setting, as it provides the chemical-rich fluids supporting the food web, creates the patchwork of seafloor habitat, and generates catastrophic disturbances that can eradicate entire communities. The patches of vent habitat host a network of communities (a metacommunity) connected by dispersal of planktonic larvae. The dynamics of the metacommunity are influenced not only by birth rates, death rates and interactions of populations at the local site, but also by regional influences on dispersal from different sites. The connections to other communities provide a mechanism for dynamics at a local site to affect features of the regional biota. In this paper, we explore the challenges and potential benefits of applying metacommunity theory to vent communities, with a particular focus on effects of disturbance. We synthesize field observations to inform models and identify data gaps that need to be addressed to answer key questions including: (1) what is the influence of the magnitude and rate of disturbance on ecological attributes, such as time to extinction or resilience in a metacommunity; (2) what interactions between local and regional processes control species diversity, and (3) which communities are “hot spots” of key ecological significance. We conclude by assessing our ability to evaluate resilience of vent metacommunities to human disturbance (e.g., deep-sea mining). Although the resilience of a few highly disturbed vent systems in the eastern Pacific has been quantified, these values cannot be generalized to remote locales in the western Pacific or mid Atlantic where disturbance rates are different and information on local controls is missing.LM was supported by NSF OCE 1356738 and DEB 1558904. SB was supported by the NSF DEB 1558904 and the Investment in Science Fund at Woods Hole Oceanographic Institution. MB was supported by the Austrian Science Fund grants P20190-B17 and P16774-B03. LL was supported by NSF OCE 1634172 and the JM Kaplan Fund. MN was supported by NSF DEB 1558904. Y-JW was supported by a Korean Institute of Ocean Science and Technology (KIOST) grant PM60210

    Bacterial antimicrobial metal ion resistance

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    Metals such as mercury, arsenic, copper and silver have been used in various forms as antimicrobials for thousands of years with until recently, little understanding of their mode of action. The discovery of antibiotics and new organic antimicrobial compounds during the twentieth century saw a general decline in the clinical use of antimicrobial metal compounds, with the exception of the rediscovery of the use of silver for burns treatments and niche uses for other metal compounds. Antibiotics and new antimicrobials were regarded as being safer for the patient and more effective than the metal-based compounds they supplanted. Bacterial metal ion resistances were first discovered in the second half of the twentieth century. The detailed mechanisms of resistance have now been characterized in a wide range of bacteria. As the use of antimicrobial metals is limited, it is legitimate to ask: are antimicrobial metal resistances in pathogenic and commensal bacteria important now? This review details the new, rediscovered and 'never went away' uses of antimicrobial metals; examines the prevalence and linkage of antimicrobial metal resistance genes to other antimicrobial resistance genes; and examines the evidence for horizontal transfer of these genes between bacteria. Finally, we discuss the possible implications of the widespread dissemination of these resistances on re-emergent uses of antimicrobial metals and how this could impact upon the antibiotic resistance problem

    Unconventional decoding of the AUA codon as methionine by mitochondrial tRNAMet with the anticodon f5CAU as revealed with a mitochondrial in vitro translation system

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    Mitochondrial (mt) tRNAMet has the unusual modified nucleotide 5-formylcytidine (f5C) in the first position of the anticodon. This tRNA must translate both AUG and AUA as methionine. By constructing an in vitro translation system from bovine liver mitochondria, we examined the decoding properties of the native mt tRNAMet carrying f5C in the anticodon compared to a transcript that lacks the modification. The native mt Met-tRNA could recognize both AUA and AUG codons as Met, but the corresponding synthetic tRNAMet lacking f5C (anticodon CAU), recognized only the AUG codon in both the codon-dependent ribosomal binding and in vitro translation assays. Furthermore, the Escherichia coli elongator tRNAMetm with the anticodon ac4CAU (ac4C = 4-acetylcytidine) and the bovine cytoplasmic initiator tRNAMet (anticodon CAU) translated only the AUG codon for Met on mt ribosome. The codon recognition patterns of these tRNAs were the same on E. coli ribosomes. These results demonstrate that the f5C modification in mt tRNAMet plays a crucial role in decoding the nonuniversal AUA codon as Met, and that the genetic code variation is compensated by a change in the tRNA anticodon, not by a change in the ribosome. Base pairing models of f5C-G and f5C-A based on the chemical properties of f5C are presented
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