4,991 research outputs found

    Gravitational waves from BH-NS binaries: Effective Fisher matrices and parameter estimation using higher harmonics

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    Inspiralling black hole-neutron star (BH-NS) binaries emit a complicated gravitational wave signature, produced by multiple harmonics sourced by their strong local gravitational field and further modulated by the orbital plane's precession. Some features of this complex signal are easily accessible to ground-based interferometers (e.g., the rate of change of frequency); others less so (e.g., the polarization content); and others unavailable (e.g., features of the signal out of band). For this reason, an ambiguity function (a diagnostic of dissimilarity) between two such signals varies on many parameter scales and ranges. In this paper, we present a method for computing an approximate, effective Fisher matrix from variations in the ambiguity function on physically pertinent scales which depend on the relevant signal to noise ratio. As a concrete example, we explore how higher harmonics improve parameter measurement accuracy. As previous studies suggest, for our fiducial BH-NS binaries and for plausible signal amplitudes, we see that higher harmonics at best marginally improve our ability to measure parameters. For non-precessing binaries, these Fisher matrices separate into intrinsic (mass, spin) and extrinsic (geometrical) parameters; higher harmonics principally improve our knowledge about the line of sight. For the precessing binaries, the extra information provided by higher harmonics is distributed across several parameters. We provide concrete estimates for measurement accuracy, using coordinates adapted to the precession cone in the detector's sensitive band.Comment: 19 pages, 11 figure

    Scour depth around multiple piles for current and wave

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    Experiments on scour around multiple piles were carried out for several current and wave conditions: pile numbers were 1, 3, and 7; and wave only, current only, and current and wave flows. A moderate wave condition was chosen as the representative wave, which produced relatively small scour depth. A depth-average current speed was chosen as the representative current, which produced relatively large scour hole. When waves were superimposed on current, scour hole depth decreased. Existing the Sumer and Fredsøe’s prediction formula of scour hole depth for current and wave flows for multiple piles describes the present experimental results reasonably well

    End-to-End Differentiable Learning to HDR Image Synthesis for Multi-exposure Images

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    Recently, high dynamic range (HDR) image reconstruction based on the multiple exposure stack from a given single exposure utilizes a deep learning framework to generate high-quality HDR images. These conventional networks focus on the exposure transfer task to reconstruct the multi-exposure stack. Therefore, they often fail to fuse the multi-exposure stack into a perceptually pleasant HDR image as the inversion artifacts occur. We tackle the problem in stack reconstruction-based methods by proposing a novel framework with a fully differentiable high dynamic range imaging (HDRI) process. By explicitly using the loss, which compares the network's output with the ground truth HDR image, our framework enables a neural network that generates the multiple exposure stack for HDRI to train stably. In other words, our differentiable HDR synthesis layer helps the deep neural network to train to create multi-exposure stacks while reflecting the precise correlations between multi-exposure images in the HDRI process. In addition, our network uses the image decomposition and the recursive process to facilitate the exposure transfer task and to adaptively respond to recursion frequency. The experimental results show that the proposed network outperforms the state-of-the-art quantitative and qualitative results in terms of both the exposure transfer tasks and the whole HDRI process

    Metnase Mediates Loading of Exonuclease 1 onto Single Strand Overhang DNA for End Resection at Stalled Replication Forks

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    Stalling at DNA replication forks generates stretches of single-stranded (ss) DNA on both strands that are exposed to nucleolytic degradation, potentially compromising genome stability. One enzyme crucial for DNA replication fork repair and restart of stalled forks in human is Metnase (also known as SETMAR), a chimeric fusion protein consisting of a su(var)3-9, enhancer-of-zeste and trithorax (SET) histone methylase and transposase nuclease domain. We previously showed that Metnase possesses a unique fork cleavage activity necessary for its function in replication restart and that its SET domain is essential for recovery from hydroxyurea-induced DNA damage. However, its exact role in replication restart is unclear. In this study, we show that Metnase associates with exonuclease 1 (Exo1), a 5'-exonuclease crucial for 5'-end resection to mediate DNA processing at stalled forks. Metnase DNA cleavage activity was not required for Exo1 5'-exonuclease activity on the lagging strand daughter DNA, but its DNA binding activity mediated loading of Exo1 onto ssDNA overhangs. Metnase-induced enhancement of Exo1-mediated DNA strand resection required the presence of these overhangs but did not require Metnase's DNA cleavage activity. These results suggest that Metnase enhances Exo1-mediated exonuclease activity on the lagging strand DNA by facilitating Exo1 loading onto a single strand gap at the stalled replication fork

    Mefenacet [2-(1,3-benzothia­zol-2-yl­oxy)-N-methyl-N-phenyl­acetamide]

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    The title compound, C16H14N2O2S, crystallizes with two independent mol­ecules in the asymmetric unit. The dihedral angles between the plane of the benzothia­zole ring system and the phenyl ring plane are 51.63 (7) and 60.46 (5)°. In the crystal structure, weak inter­molecular C—H⋯O hydrogen bonds and C—H⋯π inter­actions contribute to the stabilization of the packing

    Impacts of gender, weather, and workplace differences in farm worker's gear

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    Background: The farmers cannot help working in outdoor conditions which have high humidity and solar radiation during the harvest period. Wearable items including clothing are the nearest environment of human body, and to understand the current state of them can be a way to set up an active prevention strategy against the health risk from heat stress in summertime agriculture. The aim of this study was to investigate the work wear and accessories which the elderly farmers used during agricultural working. Methods: One hundred twenty farmers (49 males and 71 females) working in nine separate sites on different days took part in this study. The average age of subjects was 61 years old. We examined the types of working posture, clothing, and items that the farmers used and/or wore. We also interviewed the farmers to know why they used such items while working. Results: The results of this study were as follows: (1) Farmers worked in the thermal environment which was over wet bulb globe temperature (WBGT) reference value, and the farmers could suffer heat stress due to workload induced from wearing conventional long-sleeved shirts and long trousers which were 0.66 clo in average under this summertime working thermal condition. (2) The farmers tended to change the layer of upper clothing for adapting to weather condition. (3) The types of footwear used seemed to be related with facilities as well as weather, and farmers tended to wear lighter footwear when the weather is hotter or when they work in PVC greenhouse. The majority of elderly farmers wore loafers and rubber shoes which had indistinguishable thin soles. (4) The types of hats showed the difference between facilities as well as gender and only 31.7 % of all participants used long brims. (5) Korean elderly farmers did not use any active cooling item as agricultural auxiliary tools in summer harvesting time. Conclusions: Korean elderly farmers worked in poor surroundings which could threaten their health and safety and seemed not to adjust their workload and clothing during summer harvest season. Thus, it would be necessary to monitor individual responses in order to ensure that the risk of heat stress is preventedopen
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