2,572 research outputs found

    Low Earth Orbit Environmental Effects on Space Tether Materials

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    Atomic oxygen (AO) and ultraviolet (UV) radiation erode and embrittle most polymeric materials. This research was designed to test several different materials and coatings under consideration for their application to space tethers, for resistance to these effects. The samples were vacuum dehydrated, weighed and then exposed to various levels of AO or UV radiation at the NASA Marshall Space Flight Center. They were then re-weighed to determine mass loss due to atomic oxygen erosion, inspected for damage and tensile tested to determine strength loss. The experiments determined that the Photosil coating process, while affording some protection, damaged the tether materials worse than the AO exposure. TOR-LM also failed to fully protect the materials, especially from UV radiation. The POSS and nickel coatings did provide some protection to the tethers, which survived the entire test regime. M5 was tested, uncoated, and survived AO exposure, though its brittleness prevented any tensile testing

    Common Host Responses in Murine Aerosol Models of Infection Caused by Highly Virulent Gram-Negative Bacteria from the Genera Burkholderia, Francisella and Yersinia

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    This is the final version. Available on open access from MDPI via the DOI in this recordContent includes material subject to Š Crown copyright (2019), Dstl. This material is licensed under the terms of the Open Government Licence except where otherwise stated. To view this licence, visit: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: [email protected] virulent bacterial pathogens cause acute infections which are exceptionally difficult to treat with conventional antibiotic therapies alone. Understanding the chain of events that are triggered during an infection of a host has the potential to lead to new therapeutic strategies. For the first time, the transcriptomic responses within the lungs of Balb/C mice have been compared during an acute infection with the intracellular pathogens Burkholderia pseudomallei, Francisella tularensis and Yersinia pestis. Temporal changes were determined using RNAseq and a bioinformatics pipeline; expression of protein was also studied from the same sample. Collectively it was found that early transcriptomic responses within the infected host were associated with the (a) slowing down of critical cellular functions, (b) production of circulatory system components, (c) lung tissue integrity, and (d) intracellular regulatory processes. One common molecule was identified, Errfi1 (ErbB receptor feedback inhibitor 1); upregulated in response to all three pathogens and a potential novel marker of acute infection. Based upon the pro-inflammatory responses observed, we sought to synchronise each infection and report that 24 h p.i. of B. pseudomallei infection closely aligned with 48 h p.i. of infection with F. tularensis and Y. pestis. Post-transcriptional modulation of RANTES expression occurred across all pathogens, suggesting that these infections directly or indirectly modulate cell trafficking through chemokine expression/detection. Collectively, this unbiased NGS approach has provided an in-depth characterisation of the host transcriptome following infection with these highly virulent pathogens ultimately aiding in the development of host-directed therapies as adjuncts or alternatives to antibiotic treatment

    The Emerging Aversion to Inequality: Evidence from Poland 1992-2005

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    This paper provides an illustration of the changing tolerance for inequality in a context of radical political and economic transformation and rapid economic growth. We focus on the Polish experience of transition and explore self-declared attitudes of the citizens. Using monthly representative surveys of the population, realized by the Polish poll institute (CBOS) from 1992 to 2005, we identify a structural break in the relation between income inequality and subjective evaluation of well-being. The downturn in the tolerance for inequality (1997) coincides with the increasing distrust of political elites.http://deepblue.lib.umich.edu/bitstream/2027.42/64387/1/wp919.pd

    Fractional power-law susceptibility and specific heat in low temperature insulating state of o-TaS_{3}

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    Measurements of the magnetic susceptibility and its anisotropy in the quasi-one-dimensional system o-TaS_{3} in its low-T charge density wave (CDW) ground state are reported. Both sets of data reveal below 40 K an extra paramagnetic contribution obeying a power-law temperature dependence \chi(T)=AT^{-0.7}. The fact that the extra term measured previously in specific heat in zero field, ascribed to low-energy CDW excitations, also follows a power law C_{LEE}(0,T)=CT^{0.3}, strongly revives the case of random exchange spin chains. Introduced impurities (0.5% Nb) only increase the amplitude C, but do not change essentially the exponent. Within the two-level system (TLS) model, we estimate from the amplitudes A and C that there is one TLS with a spin s=1/2 localized on the chain at the lattice site per cca 900 Ta atoms. We discuss the possibility that it is the charge frozen within a soliton-network below the glass transition T_{g}~40 K determined recently in this system.Comment: 7 pages, 3 figures, submitted to Europhysics Letter

    Sexuality and Affection among Elderly German Men and Women in Long-Term Relationships: Results of a Prospective Population-Based Study

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The study was funded by the German Federal Ministry for Families, Senior Citizens, Women and Youth (AZ 314-1722-102/16; AZ 301-1720-295/2), the Ministry for Science, Research and Art Baden-WĂźrttemberg, and the University of Rostock (FORUN 989020; 889048)

    Inference on inspiral signals using LISA MLDC data

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    In this paper we describe a Bayesian inference framework for analysis of data obtained by LISA. We set up a model for binary inspiral signals as defined for the Mock LISA Data Challenge 1.2 (MLDC), and implemented a Markov chain Monte Carlo (MCMC) algorithm to facilitate exploration and integration of the posterior distribution over the 9-dimensional parameter space. Here we present intermediate results showing how, using this method, information about the 9 parameters can be extracted from the data.Comment: Accepted for publication in Classical and Quantum Gravity, GWDAW-11 special issu

    Explore the concept of “light” and its interaction with matter: an inquiry-based science education project in primary school

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    The exploration process leading to the understanding of physical phenomena, such as light and its interaction with matter, raises great interest and curiosity in children. However, in most primary schools, children rarely have the opportunity to conduct science activities in which they can engage in an enquiry process even if by the action of the teacher. In this context, we have organised several in-service teacher training courses and carried out several pedagogic interventions in Portuguese primary schools, with the aim of promoting inquirybased science education. This article describes one of those projects, developed with a class of the third grade, which explored the curricular topic “Light Experiments”. Various activities were planned and implemented, during a total of ten hours spread over five lessons. The specific objectives of this paper are: to illustrate and analyse the teaching and learning process promoted in the classroom during the exploration of one of these lessons, and to assess children’s learning three weeks after the lessons. The results suggest that children made significant learning which persisted. We conclude discussing some processes that stimulated children’ learning, including the importance of teacher questioning in scaffolding children's learning and some didactic implications for teacher training.CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), Portuga

    Ultra-High Energy Neutrino Fluxes: New Constraints and Implications

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    We apply new upper limits on neutrino fluxes and the diffuse extragalactic component of the GeV gamma-ray flux to various scenarios for ultra high energy cosmic rays and neutrinos. As a result we find that extra-galactic top-down sources can not contribute significantly to the observed flux of highest energy cosmic rays. The Z-burst mechanism where ultra-high energy neutrinos produce cosmic rays via interactions with relic neutrinos is practically ruled out if cosmological limits on neutrino mass and clustering apply.Comment: 10 revtex pages, 9 postscript figure

    The impact of networks on clinical trials in the United Kingdom

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    The conduct of clinical trials in the UK has been affected by the recent introduction of managed clinical networks, clinical research networks and rigorous governance regulations. This commentary considers the challenges that these changes have posed for clinical triallists in the UK, based on experiences derived in the conduct of a multicentre neonatal clinical trial under the conditions that now prevail. We conclude that the considerable skills and knowledge that are now required to be an effective Principal Investigator should be recognised and that application processes, including issuing honorary contracts, should be simplified and centralised
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