4,092 research outputs found

    A Novel Taxonomy of Opportunities and Risks in Massively Multiplayer Online Role Playing Games

    Get PDF
    The explosion and rapid embrace of Massively Multiplayer Online Role Playing Games (MMORPG) has provided players with unique, fully immersive three dimensional environments in which they can express themselves in a myriad of ways. Players can develop unique skill sets, share knowledge, explore and experiment with various identities and network with like-minded individuals. Evidence suggests however, that these opportunities are accompanied with a number of risks including addiction, desensitisation and threats to the privacy of personal information. This paper presents a novel Taxonomy of opportunities and risks in the specific context of Massively Multiplayer Online Role Playing Games

    Gradient-Free Stochastic Sensitivity Analysis of the Shipboard Power System

    Get PDF
    Sensitivity analysis results are useful both for the early design stage – where the parametric space can be substantially reduced – but also in operating conditions, e.g. of the future electric ship, resulting in reduced operational costs and increased reliability. Here we discuss variance-based methods to analyze the sensitivity of stochastic electro-mechanical systems with multirate dynamics. We present results for an illustrative example and for a model of an integrated power system.United States. Office of Naval Research (N00014-02-1-0623); United States. Office of Naval Research (N00014-07-1-0846); Massachusetts Institute of Technology. Sea Grant College Program (NA060AR4170019 NOAA/DOC

    Large enhancement of the thermopower in Nax_xCoO2_2 at high Na doping

    Full text link
    Research on the oxide perovskites has uncovered electronic properties that are strikingly enhanced compared with those in conventional metals. Examples are the high critical temperatures of the cuprate superconductors and the colossal magnetoresistance in the manganites. The conducting layered cobaltate NaxCoO2\rm Na_xCoO_2 displays several interesting electronic phases as xx is varied including water-induced superconductivity and an insulating state that is destroyed by field. Initial measurements showed that, in the as-grown composition, NaxCoO2\rm Na_xCoO_2 displays moderately large thermopower SS and conductivity σ\sigma. However, the prospects for thermoelectric cooling applications faded when the figure of merit ZZ was found to be small at this composition (0.6<x<<x<0.7). Here we report that, in the poorly-explored high-doping region x>x>0.75, SS undergoes an even steeper enhancement. At the critical doping xp∼x_p\sim 0.85, ZZ (at 80 K) reaches values ∼\sim40 times larger than in the as-grown crystals. We discuss prospects for low-temperature thermoelectric applications.Comment: 6 pages, 7 figure

    IL-33 promotes ST2-dependent lung fibrosis by the induction of alternatively activated macrophages and innate lymphoid cells in mice

    Get PDF
    Background&lt;p&gt;&lt;/p&gt; The initiation and regulation of pulmonary fibrosis are not well understood. IL-33, an important cytokine for respiratory diseases, is overexpressed in the lungs of patients with idiopathic pulmonary fibrosis.&lt;p&gt;&lt;/p&gt; Objectives&lt;p&gt;&lt;/p&gt; We aimed to determine the effects and mechanism of IL-33 on the development and severity of pulmonary fibrosis in murine bleomycin-induced fibrosis.&lt;p&gt;&lt;/p&gt; Methods&lt;p&gt;&lt;/p&gt; Lung fibrosis was induced by bleomycin in wild-type or Il33r (St2)−/− C57BL/6 mice treated with the recombinant mature form of IL-33 or anti–IL-33 antibody or transferred with type 2 innate lymphoid cells (ILC2s). The development and severity of fibrosis was evaluated based on lung histology, collagen levels, and lavage cytology. Cytokine and chemokine levels were quantified by using quantitative PCR, ELISA, and cytometry.&lt;p&gt;&lt;/p&gt; Results&lt;p&gt;&lt;/p&gt; IL-33 is constitutively expressed in lung epithelial cells but is induced in macrophages by bleomycin. Bleomycin enhanced the production of the mature but reduced full-length form of IL-33 in lung tissue. ST2 deficiency, anti–IL-33 antibody treatment, or alveolar macrophage depletion attenuated and exogenous IL-33 or adoptive transfer of ILC2s enhanced bleomycin-induced lung inflammation and fibrosis. These pathologic changes were accompanied, respectively, by reduced or increased IL-33, IL-13, TGF-β1, and inflammatory chemokine production in the lung. Furthermore, IL-33 polarized M2 macrophages to produce IL-13 and TGF-β1 and induced the expansion of ILC2s to produce IL-13 in vitro and in vivo.&lt;p&gt;&lt;/p&gt; Conclusions&lt;p&gt;&lt;/p&gt; IL-33 is a novel profibrogenic cytokine that signals through ST2 to promote the initiation and progression of pulmonary fibrosis by recruiting and directing inflammatory cell function and enhancing profibrogenic cytokine production in an ST2- and macrophage-dependent manner

    Thermal and Electrical Properties of gamma-NaxCoO2 (0.70 < x < 0.78)

    Full text link
    We have performed specific heat and electric resistivity measurements of Nax_{x}CoO2_{2} (x=0.70x=0.70-0.78). Two anomalies have been observed in the specific heat data for x=0.78x=0.78, corresponding to magnetic transitions at Tc=22T_{c}=22 K and Tk≃9T_{k}\simeq 9 K reported previously. In the electrical resistivity, a steep decrease at TcT_{c} and a bending-like variation at TbT_{b}(=120K for x=0.78x=0.78) have been observed. Moreover, we have investigated the xx-dependence of these parameters in detail. The physical properties of this system are very sensitive to xx, and the inconsistent results of previous reports can be explained by a small difference in xx. Furthermore, for a higher xx value, a phase separation into Na-rich and Na-poor domains occurs as we previously proposed, while for a lower xx value, from characteristic behaviors of the specific heat and the electrical resistivity at the low-temperature region, the system is expected to be in the vicinity of the magnetic instability which virtually exists below x=0.70x=0.70.Comment: 4 pages (3 figures included) and an extra figure (gif), to be published in J. Phys. Soc. Jpn. 73 (9) with possible minor revision

    NMR studies of Successive Phase Transitions in Na0.5CoO2 and K0.5CoO2

    Full text link
    59Co- and 23Na-NMR measurements have been carried out on polycrystalline and c-axis aligned samples of Na0.5CoO2, which exhibits successive transitions at temperatures T = 87 K (= Tc1) and T = 53 K (= Tc2). 59Co-NMR has also been carried out on c-axis aligned crystallites of K0.5CoO2 with similar successive transitions at Tc1 ~ 60 K and Tc2 ~ 20 K. For Na0.5CoO2, two sets of three NMR lines of 23Na nuclei explained by considering the quadrupolar frequencies nuQ ~1.32 and 1.40 MHz have been observed above Tc1, as is expected from the crystalline structure. Rather complicated but characteristic variation of the 23Na-NMR spectra has been observed with varying T through the transition temperatures, and the internal fields at two crystallographically distinct Na sites are discussed on the basis of the magnetic structures reported previously. The internal fields at two distinct Co sites observed below Tc1 and the 591/T1-T curves of Na0.5CoO2 and K0.5CoO2 are also discussed in a comparative way.Comment: 7 pages, 10 figures, submitted to J. Phys. Soc. Jpn, correction is made in right colum of p6 (35th line) as K0.5CoO2-->Na0.5CoO

    Effect of Condensed Tannin in Lotus Corniculatus and Lotus Pedunculatus on Digestion of Rubisco in the Rumen

    Get PDF
    The in vitro precipitation of ribulose-1,5-bisphosphate carboxylase (Rubisco) by condensed tannin (CT) extracted from Lotus corniculatus and Lotus pedunculatus and the effect of these CT on the in vitro rumen degradation of Rubisco was used to compare the reactivity of these CT. The chemical structure of CT from Lotus corniculatus was homogenous with epicatechin stereochemistry and mostly procyanidin units. The CT from Lotus pedunculatus was heterogenous with mostly prodelphinidin units. The amount of CT required to precipitate all the Rubisco when total soluble leaf protein was incubated with CT from Lotus corniculatus and Lotus pedunculatus was similar. Although CT from both species were able to reduce the in vitro degradation of Rubisco, CT from Lotus corniculatus was less effective than CT from Lotus pedunculatus at reducing this degradation

    A novel route to phase formation of cobalt oxyhydrates using KMnO4 as an oxidizing agent

    Full text link
    We have first succeefully synthesized the sodium cobalt oxyhydrate superconductors using KMnO4 as a de-intercalating and oxidizing agent. It is a novel route to form the superconductive phase of NaxCoO2.yH2O without resorting to the commonly used Br2/CH3CN solution. The role of the KMnO4 is to de-intercalate the Na+ from the parent compound Na0.7CoO2 and oxidize the Co ion as a result. The higher molar ratio of KMnO4 relative to the sodium content tends to remove more Na+ from the parent compound and results in a slight expansion of the c-axis in the unit cell. The superconducting transition temperature is 4.6-3.8 K for samples treated by the aqueous KMnO4 solution with the molar ratio of KMnO4 relative to the sodium content in the range of 0.3 and 2.29.Comment: 10 pages, 3 figure
    • …
    corecore