588 research outputs found

    Large Winding Sector of AdS/CFT

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    We study a family of classical strings on R x S^3 subspace of the AdS_5 x S^5 background that interpolates between pulsating strings and single-spike strings. They are obtained from the helical strings of hep-th/0609026 by interchanging worldsheet time and space coordinates, which maps rotating/spinning string states with large spins to oscillating states with large winding numbers. From a finite-gap perspective, this transformation is realised as an interchange of quasi-momentum and quasi-energy defined for the algebraic curve. The gauge theory duals are also discussed, and are identified with operators in the non-holomorphic sector of N=4 super Yang-Mills. They can be viewed as excited states above the ``antiferromagnetic'' state, which is ``the farthest from BPS'' in the spin-chain spectrum. Furthermore, we investigate helical strings on AdS_3 x S^1 in an appendix.Comment: 1+52 pages, 10 figures, v2: references and comments added, v3: minor changes and a reference adde

    Cellular Control of Dengue Virus Replication: Role of Interferon-Inducible Genes

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    Dengue, one of the most common mosquito‐borne viral infectious diseases in the world, is caused by the dengue virus (DENV). This enveloped RNA virus has immunologically distinct serotypes that increase the risk of life‐threatening diseases, such as dengue haemorrhagic fever. However, no effective antiviral therapy against DENV infection has yet been established. As seen in other RNA viruses, various cellular factors have been reported to participate in efficient DENV replication. On the other hand, increasing recent evidence demonstrates that host cells harbour inhibitory factors that limit the DENV replication. In particular, it is well known that the response of interferons (IFNs), the first line of a host defence system against invading pathogens, evokes the expression of a number of genes that negatively regulate various steps of virus replication. This set of inhibitory genes, called interferon‐stimulated genes (ISGs), is considered to be a central force in IFN‐mediated antiviral responses. In this chapter, we focus our attention on the cellular factors involved in DENV infection, particularly to those that modulate DENV replication through their association with viral RNA. In addition, we also summarize general experimental approaches for identifying the host factors of RNA viruses, including DENV

    KINEMATICS OF MEN STRIKING MOTION IN EIGHTH DAN KENDO PLAYERS

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    The purpose of this study was to explore the time series kinematic variations during the men striking motion in eighth dan kendo players. Moreover, the magnitude of the individual difference and timing at which it appeared were investigated. Ten eighth dan kendo players performed men striking towards one of two targets (men or kote) with maximum effort immediately after an LED lamp was lighted. The motions were recorded using a motion capture system. This study examined the time series kinematic variations during the men striking motion, and revealed that the movements of the shinai (sword), right and left shoulders, and right hip differed substantially among individuals from each standard deviation

    Stein Variational Guided Model Predictive Path Integral Control: Proposal and Experiments with Fast Maneuvering Vehicles

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    This paper presents a novel Stochastic Optimal Control (SOC) method based on Model Predictive Path Integral control (MPPI), named Stein Variational Guided MPPI (SVG-MPPI), designed to handle rapidly shifting multimodal optimal action distributions. While MPPI can find a Gaussian-approximated optimal action distribution in closed form, i.e., without iterative solution updates, it struggles with multimodality of the optimal distributions, such as those involving non-convex constraints for obstacle avoidance. This is due to the less representative nature of the Gaussian. To overcome this limitation, our method aims to identify a target mode of the optimal distribution and guide the solution to converge to fit it. In the proposed method, the target mode is roughly estimated using a modified Stein Variational Gradient Descent (SVGD) method and embedded into the MPPI algorithm to find a closed-form "mode-seeking" solution that covers only the target mode, thus preserving the fast convergence property of MPPI. Our simulation and real-world experimental results demonstrate that SVG-MPPI outperforms both the original MPPI and other state-of-the-art sampling-based SOC algorithms in terms of path-tracking and obstacle-avoidance capabilities. Source code: https://github.com/kohonda/proj-svg_mppiComment: 7 pages, 5 figure

    Auxin signaling is essential for organogenesis but not for cell survival in the liverwort Marchantia polymorpha

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    ゼニゴケを用いて植物ホルモンの役割を証明 --オーキシン信号伝達なくして器官形成なし--. 京都大学プレスリリース. 2023-02-07.Auxin plays pleiotropic roles in plant development via gene regulation upon its perception by the receptors TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFBs). This auxin-regulated transcriptional control mechanism originated in the common ancestor of land plants. Although the complete loss of TIR1/AFBs causes embryonic lethality in Arabidopsis thaliana, it is unclear whether the requirement for TIR1-mediated auxin perception in cell viability can be generalized. The model liverwort Marchantia polymorpha has a minimal auxin signaling system with only a single TIR1/AFB, MpTIR1. Here we show by genetic, biochemical, and transcriptomic analyses that MpTIR1 functions as an evolutionarily conserved auxin receptor. Null mutants and conditionally knocked-out mutants of MpTIR1 were viable but incapable of forming any organs and grew as cell masses. Principal component analysis performed using transcriptomes at various developmental stages indicated that MpTIR1 is involved in the developmental transition from spores to organized thalli, during which apical notches containing stem cells are established. In Mptir1 cells, stem cell- and differentiation-related genes were up- and downregulated, respectively. Our findings suggest that, in M. polymorpha, auxin signaling is dispensable for cell division but is essential for three-dimensional patterning of the plant body by establishing pluripotent stem cells for organogenesis, a derived trait of land plants

    Room-temperature deformation of single crystals of the sigma-phase compound FeCr with the tetragonal D8b structure investigated by micropillar compression

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    The deformation behavior of single crystals of the sigma-phase compound FeCr with the tetragonal D8b structure has been investigated by micropillar compression at room temperature as a function of crystal orientation and specimen size. In spite of the repeatedly reported brittleness, plastic flow is observed at room temperature for all loading axis orientations tested. Three slip systems, {100}[001], {100} and {111} are newly identified to be operative at room temperature depending on the loading axis, in addition to {110}[001] slip we previously identified. The CRSS values for all the identified slip systems are very high exceeding 1.3 GPa and decrease with increasing specimen size, following an inverse power-law relationship with a very small power-law exponent. Similarly to {110}[001] slip, {100}[001] slip is confirmed to be carried by the motion of [001] zonal dislocations through atomic-resolution scanning transmission electron microscopy imaging of their core structures. dislocations gliding on {100} are confirmed to dissociate into two collinear partial dislocations, while dislocations gliding on {111} to dissociate into three collinear partial dislocations. The fracture toughness values estimated by micro-cantilever bend tests of chevron-notched micro beam specimens are indeed very low, 1.6∼1.8 MPa·m1/2 (notch plane // (001) and (100)), indicating significant brittleness of sigma FeCr

    BIOMECHANICAL STUDY ON DIFFERENT DIRECTIONS FOR RUNNING JUMPS FOCUSED ON THE TAKEOFF PREPARATION

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    This study aimed to elucidate the difference in CG parameters from three steps, prejump to takeoff step of the jump motion (running jump), and obtain primary data on takeoff preparation action. Five male jumpers associated with the university track and field department were trained to perform their best at (1) approach run with no takeoff (RUN), (2) jumping as far as possible (long jump [LJ]), and (3) jumping as high as possible (high jump [HJ]), which were recorded using a three-dimensional capture system. As a result, significant differences were observed in not only the takeoff but also the takeoff preparation phase regarding CG parameters, suggesting the need to focus on the takeoff preparation phase as a factor that determines jump direction. Moreover, HJ and LJ suppressed an increase in vertical velocity one step prior, and by takeoff at a lower CG, the athletes allowed for an easier increase in takeoff angle and jump height. However, to resist a decrease in horizontal velocity, LJ transitioned to takeoff in a manner closer to RUN and without changing takeoff preparation as much as that in HJ. Thus, adjusting vertical velocity and height one step before takeoff can influence takeoff angle
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