287 research outputs found
International Stock Market Efficiency: A Non-Bayesian Time-Varying Model Approach
This paper develops a non-Bayesian methodology to analyze the time-varying
structure of international linkages and market efficiency in G7 countries. We
consider a non-Bayesian time-varying vector autoregressive (TV-VAR) model, and
apply it to estimate the joint degree of market efficiency in the sense of Fama
(1970, 1991). Our empirical results provide a new perspective that the
international linkages and market efficiency change over time and that their
behaviors correspond well to historical events of the international financial
system.Comment: 21 pages, 2 tables, 6 figure
Villous Tumor of the Urinary Bladder Resembling Low-grade Mucinous Neoplasm of the Appendix
AbstractMucinous neoplasms of the urinary tract are very rare. We present a 63-year-old-women who had a sessile papillary villous tumor in urinary bladder. Although transurethral resection of the bladder tumor (TURBT) was performed, the villous tumor repetitively recurred and gradually spread to the entire surface of bladder lumen. Histopathologic and immunohistochemical examination showed that the lesion was very similar to low-grade mucinous neoplasm arising in appendix vermiformis. There are no reports on appendiceal metaplasia of urinary bladder mucosa. In this case, we describe this unprecedented neoplasm as “villous tumor of the urinary bladder resembling low-grade mucinous neoplasm of the appendix.
Theory of Acceleration of Decision Making by Correlated Time Sequences
Photonic accelerators have been intensively studied to provide enhanced
information processing capability to benefit from the unique attributes of
physical processes. Recently, it has been reported that chaotically oscillating
ultrafast time series from a laser, called laser chaos, provide the ability to
solve multi-armed bandit (MAB) problems or decision-making problems at GHz
order. Furthermore, it has been confirmed that the negatively correlated
time-domain structure of laser chaos contributes to the acceleration of
decision-making. However, the underlying mechanism of why decision-making is
accelerated by correlated time series is unknown. In this study, we demonstrate
a theoretical model to account for accelerating decision-making by correlated
time sequence. We first confirm the effectiveness of the negative
autocorrelation inherent in time series for solving two-armed bandit problems
using Fourier transform surrogate methods. We propose a theoretical model that
concerns the correlated time series subjected to the decision-making system and
the internal status of the system therein in a unified manner, inspired by
correlated random walks. We demonstrate that the performance derived
analytically by the theory agrees well with the numerical simulations, which
confirms the validity of the proposed model and leads to optimal system design.
The present study paves the way for improving the effectiveness of correlated
time series for decision-making, impacting artificial intelligence and other
applications
Deafness in occludin-deficient mice with dislocation of tricellulin and progressive apoptosis of the hair cells
Occludin is the first identified protein in the tight junction (TJ), but its function has remained for the most part obscure. TJs have been demonstrated to play important roles in the inner ear function, and occludin is expressed in all the epithelial TJs in the inner ear. Thus, we examined the inner ears of occludin-deficient (Occ(-/-)) mice. Although inner ears initially developed normally in Occ(-/-) mice, apoptosis occurs in hair cells in the organ of Corti around day 12 after birth, and deafness develops. Since hair cell degeneration was not observed in cochlear explant cultures of Occ(-/-) mice, environmental changes were considered to be the trigger of cell death. As for the vestibular system, both the morphologies and functions are normal in Occ(-/-) mice. These phenotypes of Occ(-/-) mice are very similar with those of claudin-14 or claudin-9 deficient mice, leading us to speculate on the existence of imbalance induced by TJ abnormalities, such as localized ionic components. Moreover, the occludin deficiency led to dislocalization of tricellulin, a gene responsible for human deafness DFNB49. The deafness in Occ(-/-) mice may be due to this dislocalization of tricellulin.ArticleBIOLOGY OPEN.3(8):759-766(2014)journal articl
Retrobulbar Hemodynamic Effects of Nipradilol in Normal and Normal-Tension Glaucoma Eyes
Purpose. To investigate the effects of nipradilol on retrobulbar hemodynamics. Methods. We investigated normal and normal-tension glaucoma (NTG) eyes. Topical nipradilol (one eye) and placebo eye drops (fellow eye) were instilled for 1 week in volunteers. Nipradilol was also instilled in NTG patients. Ultrasound color Doppler imaging for the posterior vessels was performed before, 2 hr, 1 week (for normal), and at 4 weeks (for NTG). Results. In normal eyes, there were significant decreases in the resistance index (RI) for the temporal short posterior ciliary arteries (PCA) at 2 hr and for the ophthalmic arteries at 1 week. There were no significant changes in the placebo-treated eyes. In the NTG eyes, there was a significant decrease in the RI for the central retinal artery, nasal, and temporal PCA at 2 hr and 4 weeks. Conclusion. Short-term observations found that nipradilol increased the ocular blood flow in normal and NTG eyes
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