Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

Peer reviewe

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

The Intra-industry Transfer of Information Inferred from Announcements of Corporate Security Offerings.

This study investigates the extent to which information inferred by investors from initial announcements of corporate security offerings affects share prices in the capital markets. The empirical tests measure the response in the common stock prices of both firms announcing a security offering and nonannouncing firms operating in the same industry. Small but significantly negative abnormal returns are shown by industry shares upon initial announcements of common stock, convertible debt, and straight public offerings. Such an industry response indicates that share prices incorporate an inside assessment of factors relevant to the valuation of an industry subset of firms. Copyright 1992 by American Finance Association.

Do managers learn from the market? Firm level evidence in merger investment

Chen, Goldstein, and Jiang (2007) first present direct evidence that managers learn from the market in internal capital investment decisions. This paper extends the research to merger investment. We report that stock price firm-specific information increases the sensitivity of merger investment to Tobin\u27s Q. This relation is not driven by a particular subsample and is robust to diverse measures of stock price informativeness. It also holds when we control for related variables. Firms with more informative stock prices achieve better post-merger operating performance. Overall, these results suggest that managers learn new information from financial markets in making merger investment decisions

Stock price informativeness on the sensitivity of strategic M&A investment to Q

Using a strategic merger sample that covers the period from 1985 to 2011, we find that the acquirer’s stock price firm-specific information, the new information created by investors about the value of firm fundamentals, increases the positive sensitivity of strategic merger investment to the acquirer’s Q; the target’s stock price firm-specific information increases the negative sensitivity of merger investment to the target’s Q. These results suggest that managers learn from financial markets in identifying strategic merger investment opportunities by transferring assets from poorly managed firms to well managed firms. In addition, the target’s stock price firm-specific information itself increases the acquisition size, indicating that informed acquirer managers are more likely to take out large merger investment. Last but not the least, stock price informativeness increases merger synergies and post-merger performance, suggesting that informed managers make better merger investment that increases shareholder value. Our study contributes to the recent increasing stream of studies on managerial learning from the market

Stock price firm-specific information on the choice of stock payment in mergers and acquisitions

Previous studies on the choice of stock payment in M&A mainly focus on managerial private information. This study shows that managers also learn new firm-specific information from financial markets in making this decision. The acquirer\u27s stock price firm-specific information increases the stock-payment-to-Q sensitivity. The target\u27s stock price firm-specific information decreases the stock payment probability. Further analyses on deal and firm characteristics as well as shareholder wealth in stock mergers support the managerial learning argument. Overall, this study highlights a new set of information that affects the form of merger payment in mergers and acquisitions