1,106 research outputs found

    Net baryon number fluctuations across the chiral phase transition at finite density in the strong coupling lattice QCD

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    We investigate the net-baryon number fluctuations across the chiral phase transition at finite density in the strong coupling and chiral limit. Mesonic field fluctuations are taken into account by using the auxiliary field Monte-Carlo method. We find that the higher-order cumulant ratios, SσS\sigma and κσ2\kappa\sigma^2, show oscillatory behavior around the phase boundary at μ/T0.2\mu/T\gtrsim 0.2, and there exists the region where the higher-order cumulant ratios are negative. The negative region of κσ2\kappa\sigma^2 is found to shrink with increasing lattice size. This behavior agrees with the expectations from the scaling analysis.Comment: 16 pages, 5 figure

    pΞp\Xi^- Correlation in Relativistic Heavy Ion Collisions with Nucleon-Hyperon Interaction from Lattice QCD

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    On the basis of the pΞp\Xi^- interaction extracted from (2+1)-flavor lattice QCD simulations at the physical point, the momentum correlation of pp and Ξ\Xi^- produced in relativistic heavy ion collisions is evaluated. CSL(Q)C_{\rm SL}(Q) defined by a ratio of the momentum correlations between the systems with different source sizes is shown to be largely enhanced at low momentum due to the strong attraction between pp and Ξ\Xi^- in the I=J=0I=J=0 channel. Thus, measuring this ratio at RHIC and LHC and its comparison to the theoretical analysis will give a useful constraint on the pΞp\Xi^- interaction.Comment: 4 pages, 2 figures; proceedings contribution for Quark Matter 201

    Geometric transformations between general concurrent charts and tangential contact charts

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    summary:The general geometric transformations between the general concurrent charts of three variables and the general tangential contact charts of three variables are researched in this paper. General geometric transformations treated here are of the form: u(x,y)xˉ+v(x,y)yˉ+w(x,y)=0u(x,y)\bar{x}+v(x,y)\bar{y}+w(x,y)=0, by which the general concurrent charts in (x,y)(x,y)-plane and the general tangential contact charts in (xˉ,yˉ)(\bar{x},\bar{y})-plane are transformed to cach other, by the envelope method or the contact transformation method

    Assumption of negative events and emotion during the procrastination process

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    This study collected negative events assumed when people procrastinate, classified these negative events, and examined the relationship between types of negative events and emotions. In the pilot study, we collected negative events that were assumed when people procrastinate. The 28 items included events related to stress and to the performance of the tasks. In Study 1, we intended to select and classify the negative event items. The participants were asked how strongly they had thought that these negative events actually happen. The exploratory factor analysis showed that the negative events did not fall into multiple categories. In Study 2, participants were asked how they were concerned by 28 negative events. As in Study 1, the exploratory factor analysis showed that the negative events did not fall into more than one category. The participants were also asked about emotions in the procrastination process. We examined the relationship between those emotions and the level of concern for negative events. A positive correlation was found between “negative emotions” and “optimism about the situation” and the degree of concern about negative events during the procrastination process. These results indicate that the degree of concern is more important than the type of negative event, and that the degree is related to the occurrence of negative emotions during the procrastination process

    A micro ultrasonic motor using a micro-machined cylindrical bulk PZT transducer

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    In this paper, a micro ultrasonic motor using a micro-machined bulk piezoelectric transducer is introduced. The cylindrical shaped bulk piezoelectric transducer, a diameter of 0.8 mm and a height of 2.2 mm, was developed as stator transducer for traveling wave type ultrasonic motor. The transducer was made of lead zirconate titanate (PZT) bulk ceramics, and formed by micro machining, Ni plating and laser beam cutting process. Using this stator transducer, we have fabricated a cylindrical micro ultrasonic motor, a diameter of 2.0 mm and a height of 5.9 mm. We have also evaluated some characteristics and succeeded in driving the micro ultrasonic motor.</p

    Involvement of RNA-binding protein Hfq in the osmotic-response regulation of invE gene expression in Shigella sonnei

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    <p>Abstract</p> <p>Background</p> <p>The expression of Type III secretion system (TTSS) in <it>Shigella </it>is regulated in response to changes in environmental osmolarity and temperature. Temperature-dependent regulation of <it>virF</it>, the master regulator of TTSS synthesis, is believed to occur at the transcriptional level. We recently demonstrated, however, that TTSS synthesis also involves post-transcriptional regulation of the synthesis of InvE, a target of <it>virF </it>and key regulator of TTSS synthesis. The mRNA levels of <it>invE </it>(<it>virB</it>) are stable at 37°C, but mRNA stability markedly decreases at low temperatures where the TTSS synthesis is tightly repressed. Deletion of <it>hfq</it>, which encodes an RNA chaperone in Gram-negative bacteria, results in the restoration of expression of <it>invE </it>and other TTSS genes at low temperature due to an increase in the stability of <it>invE </it>mRNA. To date, the molecular details of the regulation of TTSS expression in response to osmotic pressure are not known. In the current study, we investigated the mechanism of regulation of TTSS by osmotic pressure.</p> <p>Results</p> <p>Transcription of <it>virF</it>, which encodes the master regulator of TTSS expression, was partially repressed under low osmotic conditions. Several lines of evidence indicated that osmolarity-dependent changes in TTSS synthesis are controlled at the post-transcriptional level, through the regulation of InvE synthesis. First, the expression InvE protein was tightly repressed under low osmotic growth conditions, even though <it>invE </it>mRNA transcripts were readily detectable. Second, under low osmotic conditions, <it>invE </it>mRNA was rapidly degraded, whereas deletion of <it>hfq</it>, which encodes an RNA chaperone, resulted in increased <it>invE </it>mRNA stability and the production of InvE protein. Third, the binding of purified Hfq <it>in vitro </it>to <it>invE </it>RNA was stronger in low-salt buffer, as assessed by gel-shift analysis and surface plasmon resonance (Biacore analysis).</p> <p>Conclusion</p> <p>Osmolarity-dependent changes in TTSS synthesis in <it>Shigella </it>involve the post-transcriptional regulation of InvE expression, in addition to partial transcriptional activation by <it>virF</it>. The stability of <it>invE </it>mRNA is reduced under low osmotic conditions, similar to the effect of temperature. Deletion of an RNA chaperone gene (<it>hfq</it>) abolished the repression of TTSS synthesis at low osmolarity through a mechanism that involved increased stability of <it>invE </it>mRNA. We propose that the expression of <it>Shigella </it>virulence genes in response to both osmolarity and temperature involves the post-transcriptional regulation of expression of InvE, a critical regulator of TTSS synthesis.</p
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