952 research outputs found

    Dark matter for excess of AMS-02 positrons and antiprotons

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    We propose a dark matter explanation to simultaneously account for the excess of antiproton-to-proton and positron power spectra observed in the AMS-02 experiment while having the right dark matter relic abundance and satisfying the current direct search bounds. We extend the Higgs triplet model with a hidden gauge symmetry of SU(2)XSU(2)_X that is broken to Z3Z_3 by a quadruplet scalar field, rendering the associated gauge bosons stable weakly-interacting massive particle dark matter candidates. By coupling the complex Higgs triplet and the SU(2)XSU(2)_X quadruplet, the dark matter candidates can annihilate into triplet Higgs bosons each of which in turn decays into lepton or gauge boson final states. Such a mechanism gives rise to correct excess of positrons and antiprotons with an appropriate choice of the triplet vacuum expectation value. Besides, the model provides a link between neutrino mass and dark matter phenomenology.Comment: 12 pages, 3 figures, references and comments added, version to appear in Phys. Lett.

    Rare BB and KK decays in a scotogenic model

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    A scotogenic model can radiatively generate the observed neutrino mass, provide a dark matter candidate, and lead to rare lepton flavor-violating processes. We aim to extend the model to establish a potential connection to the quark flavor-related processes within the framework of scotogenesis, enhancing the unexpectedly large branching ratio (BR) of B+→K+ννˉB^+\to K^+ \nu \bar\nu, observed by Belle II Collaboration. Meanwhile, the model can address tensions between some experimental measurements and standard model (SM) predictions in flavor physics, such as the muon g−2g-2 excess and the higher BR of Bs→μ−μ+B_s \to \mu^- \mu^+. We introduce in the model the following dark particles: a neutral singlet Dirac-type lepton (NN); two inert Higgs doublets (η1,2\eta_{1,2}), with one of which carrying a lepton number; a charged singlet dark scalar (χ+)(\chi^+), and a singlet vector-like up-type dark quark (TT). The first two entities are responsible for the radiative neutrino mass, and χ+\chi^+ couples to right-handed quarks and leptons and can resolve the tensions existing in muon g−2g-2 and Bs→μ−μ+B_s\to \mu^- \mu^+. Furthermore, the BR of B+→K+ννˉB^+ \to K^+ \nu \bar\nu can be enhanced up to a factor of 2 compared to the SM prediction through the mediations of the dark TT and the charged scalars. In addition, we also study the impacts on the K→πννˉK\to \pi \nu \bar\nu decays.Comment: 34 pages, 6 figures, references added, text revise

    Bubbles or cycles? Housing price dynamics in China’s major cities

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    Based on the monthly data of 35 cities during the period 2006−2017, this study adopts a recursive forward looking method to detect the presence of housing bubbles and investigate their potential cyclical patterns in China’s large and medium sized cities. Empirical results show that the number of cities reporting housing bubbles has been increasing since 2013, before it declined in 2017. Regarding regional disparities of housing bubbles, 1st-tier and 1.5-tier cities have higher probability than 2nd-tier cities for housing bubbles. In general, eastern region cities have more housing bubbles than central and western region cities, which may indicate the problem of shrinking cities China is facing nowadays. Bubble signals for market correction in major cities and municipalities seemed alarming in particular for the period 2013−2016, however it is difficult to conclude if the market adjustment in 2017 indicates a cyclical pattern. First published online 19 December 201

    Topological design of strain sensing nanocomposites

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    High-performance piezoresistive nanocomposites have attracted extensive attention because of their significant potential as next-generation sensing devices for a broad range of applications, such as monitoring structural integrity and human performance. While various piezoresistive nanocomposites have been successfully developed using different material compositions and manufacturing techniques, current development procedures typically involve empirical trial and error that can be laborious, inefficient, and, most importantly, unpredictable. Therefore, this paper proposed and validated a topological design-based methodology to strategically manipulate the piezoresistive effect of nanocomposites to achieve a wide range of strain sensitivities without changing the material system. In particular, patterned nanocomposite thin films with stress-concentrating and stress-releasing topologies were designed. The strain sensing properties of the different topology nanocomposites were characterized and compared via electromechanical experiments. Those results were compared to both linear and nonlinear piezoresistive material model numerical simulations. Both the experimental and simulation results indicated that the stress-concentrating topologies could enhance strain sensitivity, whereas the stress-releasing topologies could significantly suppress bulk film piezoresistivity

    Why We Should Report the Details in Subjective Evaluation of TTS More Rigorously

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    This paper emphasizes the importance of reporting experiment details in subjective evaluations and demonstrates how such details can significantly impact evaluation results in the field of speech synthesis. Through an analysis of 80 papers presented at INTERSPEECH 2022, we find a lack of thorough reporting on critical details such as evaluator recruitment and filtering, instructions and payments, and the geographic and linguistic backgrounds of evaluators. To illustrate the effect of these details on evaluation outcomes, we conducted mean opinion score (MOS) tests on three well-known TTS systems under different evaluation settings and we obtain at least three distinct rankings of TTS models. We urge the community to report experiment details in subjective evaluations to improve the reliability and interpretability of experimental results.Comment: Interspeech 2023 camera-ready versio

    Micro-patterned graphene-based sensing skins for human physiological monitoring.

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    Ultrathin, flexible, conformal, and skin-like electronic transducers are emerging as promising candidates for noninvasive and nonintrusive human health monitoring. In this work, a wearable sensing membrane is developed by patterning a graphene-based solution onto ultrathin medical tape, which can then be attached to the skin for monitoring human physiological parameters and physical activity. Here, the sensor is validated for monitoring finger bending/movements and for recognizing hand motion patterns, thereby demonstrating its future potential for evaluating athletic performance, physical therapy, and designing next-generation human-machine interfaces. Furthermore, this study also quantifies the sensor's ability to monitor eye blinking and radial pulse in real-time, which can find broader applications for the healthcare sector. Overall, the printed graphene-based sensing skin is highly conformable, flexible, lightweight, nonintrusive, mechanically robust, and is characterized by high strain sensitivity

    Src-homology 2 domain-containing tyrosine phosphatase 2 promotes oral cancer invasion and metastasis

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    BACKGROUND: Tumor invasion and metastasis represent a major unsolved problem in cancer pathogenesis. Recent studies have indicated the involvement of Src-homology 2 domain-containing tyrosine phosphatase 2 (SHP2) in multiple malignancies; however, the role of SHP2 in oral cancer progression has yet to be elucidated. We propose that SHP2 is involved in the progression of oral cancer toward metastasis. METHODS: SHP2 expression was evaluated in paired oral cancer tissues by using immunohistochemical staining and real-time reverse transcription polymerase chain reaction. Isogenic highly invasive oral cancer cell lines from their respective low invasive parental lines were established using a Boyden chamber assay, and changes in the hallmarks of the epithelial-mesenchymal transition (EMT) were assessed to evaluate SHP2 function. SHP2 activity in oral cancer cells was reduced using si-RNA knockdown or enforced expression of a catalytically deficient mutant to analyze migratory and invasive ability in vitro and metastasis toward the lung in mice in vivo. RESULTS: We observed the significant upregulation of SHP2 in oral cancer tissues and cell lines. Following SHP2 knockdown, the oral cancer cells markedly attenuated migratory and invasion ability. We observed similar results in phosphatase-dead SHP2 C459S mutant expressing cells. Enhanced invasiveness was associated with significant upregulation of E-cadherin, vimentin, Snail/Twist1, and matrix metalloproteinase-2 in the highly invasive clones. In addition, we determined that SHP2 activity is required for the downregulation of phosphorylated ERK1/2, which modulates the downstream effectors, Snail and Twist1 at a transcript level. In lung tissue sections of mice, we observed that HSC3 tumors with SHP2 deletion exhibited significantly reduced metastatic capacity, compared with tumors administered control si-RNA. CONCLUSIONS: Our data suggest that SHP2 promotes the invasion and metastasis of oral cancer cells. These results provide a rationale for further investigating the effects of small-molecule SHP2 inhibitors on the progression of oral cancer, and indicate a previously unrecognized SHP2-ERK1/2-Snail/Twist1 pathway that is likely to play a crucial role in oral cancer invasion and metastasis
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