161 research outputs found

    Managerial Risk Tolerance and Corporate Credit Ratings

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    This study examines whether and how managerial risk tolerance influences corporate credit ratings. Using the possession of a private pilot license to capture CEO risk tolerance, we find that firms led by pilot CEOs have worse credit ratings after controlling for firm fundamentals, CEO risk-taking incentives, and other CEO characteristics. Path analyses show that risk-tolerant CEOs lead to worse credit ratings by reducing the level of future firm value, increasing the volatility of future firm value, and changing rating agencies’ assessment of management. Also, the negative association between CEO risk tolerance and credit ratings is more pronounced when management play a more important role in a firm. Overall, our study sheds light on the dark side of managerial risk tolerance by documenting its adverse impact on corporate credit ratings

    Effects of treatment with Astragalus Membranaceus on function of rat leydig cells

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    Background Astragalus membranaceus (AM) is a Chinese traditional herb which has been reported to have broad positive effects on many diseases, including hepatitis, heart disease, diabetes and skin disease. AM can promote cell proliferation, increase the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and inhibit apoptosis by regulating the transcription of proto-oncogenes controlling cell death. While AM is included in some commercially available “testosterone boosting supplements”, studies directly testing ability of AM to modulate testosterone production are lacking. In the present study, we examined the effects of AM on Leydig cell function in vitro. Methods Rat Leydig cells were purified and treated with AM at different concentrations (0 μg/mL, 10 μg/mL, 20 μg/mL, 50 μg/mL, 100 μg/mL and 150 μg/mL) and cell counting-8 (CCK-8) assay, Enzyme-linked immunosorbent assay, quantitative real time PCR and analysis of activities of SOD and GPx were done respectively. Results Treatment with 100 μg/mL (P \u3c 0.05) and 150 μg/mL AM (P \u3c 0.01) significantly increased Leydig cell numbers. Treatment with AM (20 μg/mL, 50 μg/mL and 100 μg/mL) significantly increased testosterone production (P \u3c 0.01). In addition, increased Leydig cell SOD and GPx activities were observed in response to 20 μg/mL and 50 μg/mL AM treatment (P \u3c 0.01). Furthermore, expression of Bax mRNA was significantly decreased (P \u3c 0.01), and the ratio of Bcl-2/Bax mRNA was significantly increased in response to 20 μg/mL AM in the culture medium (P \u3c 0.05). Conclusions Results supported a beneficial effect of AM on multiple aspects of rat Leydig cell function in vitro including testosterone production

    Novel emerging nano-assisted anti-cancer strategies based on the STING pathway

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    Activation of simulator of interferon genes (STING), which induces the production of proinflammatory factors and immune effector cell activation, is considered a promising strategy for enhanced anti-cancer intervention. However, several obstacles prevent STING signaling in solid tumors, such as delivered molecules’ rapid degradation, restriction to tumor sites, insufficient intracellular concentrations, and low responsivity. Well-designed, multifunctional nano-formulations have emerged as optimized platforms for STING activation. Recently, a variety of nano-formulations have been developed and used in STING activation, thus facilitating immunotherapy in preclinical and clinical stages. Herein, we summarize recent advances in nanotechnology-based delivery, activation, and application strategies, which have advanced various aspects of immunotherapy. Novel STING agonists and their mechanisms in STING-activation-mediated tumor interventions are highlighted herein, to provide a comprehensive overview and discuss future directions for boosting immunotherapy via STING regulation

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

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    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30MM_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    Real-Time Stylized Humanoid Behavior Control through Interaction and Synchronization

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    Restricted by the diversity and complexity of human behaviors, simulating a character to achieve human-level perception and motion control is still an active as well as a challenging area. We present a style-based teleoperation framework with the help of human perceptions and analyses to understand the tasks being handled and the unknown environment to control the character. In this framework, the motion optimization and body controller with center-of-mass and root virtual control (CR-VC) method are designed to achieve motion synchronization and style mimicking while maintaining the balance of the character. The motion optimization synthesizes the human high-level style features with the balance strategy to create a feasible, stylized, and stable pose for the character. The CR-VC method including the model-based torque compensation synchronizes the motion rhythm of the human and character. Without any inverse dynamics knowledge or offline preprocessing, our framework is generalized to various scenarios and robust to human behavior changes in real-time. We demonstrate the effectiveness of this framework through the teleoperation experiments with different tasks, motion styles, and operators. This study is a step toward building a human-robot interaction that uses humans to help characters understand and achieve the tasks

    Pricing of Responsible Financial Reporting: The Perspective from Directors’ & Officers’ Liability Insurers

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    This paper studies whether and how responsible (or irresponsible) financial reporting practices are priced by insurers that sell Directors’ and Officers’ (D&O) insurance products to public firms. As D&O insurers typically assume the liabilities arising from shareholder litigation, the insurance premiums they charge for D&O policy coverage reflect their assessment of a company’s litigation risk, which, under many circumstances, can be reduced by responsible financial reporting choices and strong corporate governance practices. Using a sample of public firms in the Tillinghast D&O insurance surveys conducted between 2001 and 2004, we document that firms with lower earnings quality or prior restatements of financial numbers pay higher D&O insurance premiums after controlling for other economic factors that shape a firm’s litigation environment
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