Market Imperfections, Macroeconomic Conditions, and Capital Structure Dynamics: A Cross-Country Study

This paper investigates how “systematic” adjustment costs proxied by market imperfections and macroeconomic conditions affect capital structure dynamics in a cross-country setting. We document substantial variations in firms’ capital structure adjustments across countries and, particularly, over time. Consistent with adjustment costs impeding firms from rebalancing their capital structures, worse market imperfections are associated with slower speeds of adjustment (SOA) and larger leverage deviations. Intertemporally, capital structure adjustment is procyclical, with SOA increasing by 0.9 percentage point for a one-percentage-point increase in GDP growth rate. The procyclicality is attributable to good macroeconomic conditions mitigating market imperfections through channels of 1) facilitating free-ride restructuring, and 2) uncertainty alleviation. Our investigation features a bootstrapping-based estimation method that addresses the mechanical mean reversion of leverage ratio

The Relationships among Sea-Food Restaurant Service Quality, Perceived Value, Customer Satisfaction and Behavioral Intentions Using Structural Equation Models: a Case of Pengh

To identify the relationships among sea-food rest aurant service quality/ perceived value/satisfaction and behavioral intentions, this research establish es a study structure and formulates six hypothese s from the related literatures reviews. Structural equation models were used to validate the relatio nship based on the surveyed sample collected fro m the restaurants’ tourists. The findings indicate that overall sea-food restaurant service quality po sitively and significantly influences perceived val ue, and overall sea-food restaurant perceived valu e had a significant role in influencing satisfaction. Additionally, overall sea-food restaurant perceive d value and satisfaction are significant predictors of customer’s behavioral intentions. Customer sa tisfaction can act as a partial mediator in the rel ationship between overall sea-food restaurant serv ice quality, perceived value and behavioral intenti ons. However, restaurant’s service quality did not positively influence either the customer satisfacti on or the behavioral intentions. Furthermore, the constructs including responsiveness, assurance, an d reliability are the appropriate observations to m easure sea-food restaurant service quality which s ignificantly influences the perceived value. Theref ore, upgrading the responsiveness, assurance, and reliability on service quality in sea-food restaura nt is an effective way to increase the customers’ perceived value, satisfaction and behavioral inte ntions. This research results can be referenced by the restaurant owners/ operators in operational management

A cell-free system toward deciphering the post-translational modification barcodes of Oct4 in different cellular contexts

AbstractThe octamer-binding transcription factor 4 (Oct4) is essential for maintaining the self-renewal and pluripotency of embryonic stem cells (ESCs). Post-translational modifications (PTMs) of Oct4 critically control its structure, function and intracellular localization. However, determination of Oct4 PTM profiles has largely been restricted by the quantity and purity of the Oct4 protein samples required for mass spectrometric analyses. In this study, by incubating the Escherichia coli-derived His-tagged Oct4 proteins with the whole cell lysates of a variety of human cells followed by retrieving the reacted Oct4 proteins with the Ni–NTA beads, we developed a labor- and cost-effective in vitro PTM method that allowed for mass spectrometric determination of the phosphorylation profiles of Oct4 proteins exposed to various cell-free systems. A number of Oct4 phosphorylation sites that were commonly present in all the cell-free systems or specifically present in a particular cellular context were identified, indicating that Oct4 is controlled by both common and distinct PTM regulatory pathways. Our work provided a proof-of-concept that such a cell-free system-based in vitro PTM approach can be applied to systematically map out the physiologically-relevant PTM sites in Oct4 proteins, which opened up an avenue to fully decipher the Oct4 PTM barcodes in various cellular contexts

Improved Motor Imagery Classification Using Adaptive Spatial Filters Based on Particle Swarm Optimization Algorithm

As a typical self-paced brain-computer interface (BCI) system, the motor imagery (MI) BCI has been widely applied in fields such as robot control, stroke rehabilitation, and assistance for patients with stroke or spinal cord injury. Many studies have focused on the traditional spatial filters obtained through the common spatial pattern (CSP) method. However, the CSP method can only obtain fixed spatial filters for specific input signals. Besides, CSP method only focuses on the variance difference of two types of electroencephalogram (EEG) signals, so the decoding ability of EEG signals is limited. To obtain more effective spatial filters for better extraction of spatial features that can improve classification to MI-EEG, this paper proposes an adaptive spatial filter solving method based on particle swarm optimization algorithm (PSO). A training and testing framework based on filter bank and spatial filters (FBCSP-ASP) is designed for MI EEG signal classification. Comparative experiments are conducted on two public datasets (2a and 2b) from BCI competition IV, which show the outstanding average recognition accuracy of FBCSP-ASP. The proposed method has achieved significant performance improvement on MI-BCI. The classification accuracy of the proposed method has reached 74.61% and 81.19% on datasets 2a and 2b, respectively. Compared with the baseline algorithm (FBCSP), the proposed algorithm improves 11.44% and 7.11% on two datasets respectively. Furthermore, the analysis based on mutual information, t-SNE and Shapley values further proves that ASP features have excellent decoding ability for MI-EEG signals, and explains the improvement of classification performance by the introduction of ASP features.Comment: 25 pages, 8 figure

WW-representations of two-matrix models with infinite set of variables

The Hermitian, complex and fermionic two-matrix models with infinite set of variables are constructed. We show that these two-matrix models can be realized by the $W$-representations. In terms of the $W$-representations, we derive the compact expressions of correlators for these two-matrix models.Comment: 12 page

Did the nHZ Gravitational Waves Signatures Observed By NANOGrav Indicate Multiple Sector SUSY Breaking?

Discrete R symmetries always play an important role in low energy SUSY. The spontaneously broken of such discrete R symmetries, for example, by gaugino condensation, can lead to domain walls, which need to be either inflated away or collapse to avoid cosmic difficulties. We propose that explicitly R symmetry violation needed for collapse of domain walls can be the consequence of multiple sector SUSY breaking. The consistency constraints for the generation of non-problematic domain walls from gaugino condensation are discussed. We also study the emitted gravitational waves related to the collapse of domain walls. We find that, for SUSY breaking scale of order ${\cal O}(1)$ ${\rm GeV}$ in one of the sequestered sector (and also a low reheating temperature of order ${\rm MeV}$ if the reheating is not completed when the domain walls collapse), the peak frequency of gravitational waves emitted can lie at nHz. Such a low SUSY breaking scale can be consistency and natural in multiple sector SUSY breaking scenario. The GWs signal by NANOGrav could be a signal of such multiple sector SUSY breaking scenario and it may also indicate the existences of light goldstini at ${\rm eV}$ mass scale.Comment: 13 page