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

Performance assessment of displacement-field estimation of the human left atrium from 4D-CT images using the coherent point drift algorithm

Background: Cardiac four-dimensional computed tomography (4D-CT) imaging is a standard approach used to visualize left atrium (LA) deformation for clinical diagnosis. However, the quantitative evaluation of LA deformation from 4D-CT images is still a challenging task. We assess the performance of LA displacement-field estimation from 4D-CT images using the coherent point drift (CPD) algorithm, which is a robust point set alignment method based on the expectation–maximization (EM) algorithm. Method: Subject-specific LA surfaces at 20 phases/cardiac cycles were reconstructed from 4D-CT images and expressed as sets of triangular elements. The LA surface at the phase that maximized the LA surface area was assigned as the control LA surface and those at the other 19 phases were assigned as observed LA surfaces. The LA displacement-field was estimated by solving the alignment between the control and observation LA surfaces using CPD. Results: Global correspondences between the estimated and observed LA surfaces were successfully confirmed by quantitative evaluations using the Dice similarity coefficient and differences of surface area for all phases. The surface distances between the estimated and observed LA surfaces ranged within 2 mm, except at the left atrial appendage and boundaries, where incomplete data, such as missing or false detections, were included on the observed LA surface. We confirmed that the estimated LA surface displacement and its spatial distribution were anisotropic, which is consistent with existing clinical observations. Conclusion: These results highlight that the LA displacement field estimated by CPD robustly tracks global LA surface deformation observed in 4D-CT images

zTrap: zebrafish gene trap and enhancer trap database

<p>Abstract</p> <p>Background</p> <p>We have developed genetic methods in zebrafish by using the <it>Tol2 </it>transposable element; namely, transgenesis, gene trapping, enhancer trapping and the Gal4FF-UAS system. Gene trap constructs contain a splice acceptor and the GFP or Gal4FF (a modified version of the yeast Gal4 transcription activator) gene, and enhancer trap constructs contain the zebrafish <it>hsp70l </it>promoter and the GFP or Gal4FF gene. By performing genetic screens using these constructs, we have generated transgenic zebrafish that express GFP and Gal4FF in specific cells, tissues and organs. Gal4FF expression is visualized by creating double transgenic fish carrying a Gal4FF transgene and the GFP reporter gene placed downstream of the Gal4-recognition sequence (UAS). Further, the Gal4FF-expressing cells can be manipulated by mating with UAS effector fish. For instance, when fish expressing Gal4FF in specific neurons are crossed with the UAS:TeTxLC fish carrying the tetanus neurotoxin gene downstream of UAS, the neuronal activities are inhibited in the double transgenic fish. Thus, these transgenic fish are useful to study developmental biology and neurobiology.</p> <p>Description</p> <p>To increase the usefulness of the transgenic fish resource, we developed a web-based database named <it>z</it>Trap <url>http://kawakami.lab.nig.ac.jp/ztrap/</url>. The <it>z</it>Trap database contains images of GFP and Gal4FF expression patterns, and genomic DNA sequences surrounding the integration sites of the gene trap and enhancer trap constructs. The integration sites are mapped onto the <it>Ensembl </it>zebrafish genome by in-house Blat analysis and can be viewed on the <it>z</it>Trap and <it>Ensembl </it>genome browsers. Furthermore, <it>z</it>Trap is equipped with the functionality to search these data for expression patterns and genomic loci of interest. <it>z</it>Trap contains the information about transgenic fish including UAS reporter and effector fish.</p> <p>Conclusion</p> <p><it>z</it>Trap is a useful resource to find gene trap and enhancer trap fish lines that express GFP and Gal4FF in desired patterns, and to find insertions of the gene trap and enhancer trap constructs that are located within or near genes of interest. These transgenic fish can be utilized to observe specific cell types during embryogenesis, to manipulate their functions, and to discover novel genes and <it>cis</it>-regulatory elements. Therefore, <it>z</it>Trap should facilitate studies on genomics, developmental biology and neurobiology utilizing the transgenic zebrafish resource.</p

Differences between acoustic trauma and other types of acute noise-induced hearing loss in terms of treatment and hearing prognosis

Objectives: To evaluate the differences between acoustic trauma (AT) and other types of acute noise-induced hearing loss (ANIHL), we performed a literature search and case reviews.Methods: The literature search based on online databases was completed in September 2016. Articles on ANIHL and steroid treatment for human subjects were reviewed. The source sounds and treatment sequelae of our accumulated cases were also reviewed. Hearing loss caused by gun-shots and explosions was categorized into the AT group, while hearing loss caused by concerts and other noises was categorized into the ANIHL group.Results: Systemic steroid treatment did not appear to be effective, at least in the AT group, based on both the literature and our case reviews. However, effective recovery after treatment including steroids was observed in the ANIHL group. The difference in hearing recovery between the AT and ANIHL groups was statistically significant (p = .030), although differences in age, days from the onset to treatment and pretreatment hearing levels were not significant.Conclusions: Hearing recovery from AT is very poor, whereas, ANIHL is recoverable to some extent. Therefore, it is essential to differentiate between these two groups for accurate prediction of the hearing prognosis and evaluation of treatment effects

Stable Isotope Studies of Salts and Water from Dry Valleys, Antarctica I. Origin of Salts and Water, and the Geologic History of Lake Vanda

Possible origins of lake water and salts which are dissolved in water of saline lake, Lake Vanda, and contained in cored sediments of the lake were investigated on the basis of the stable sulfur, carbon and oxygen isotopic compositions. The present-day lake water is concluded to be neither marine nor volcanic in origin in spite of the high salt concentration, H_2S concentration and water temperature, but it is fresh surface water, and dissolved salts are of marine origin. The genesis and historical events of the saline lake also were examined. Sea water was present in the lake basin as a fjord and isolated from the ocean by glaciation after the Tertiary period. After the isolation of the lake from ocean, evaporation of lake water in cold climate and supply of glacial melt water in warm climate have alternately taken place several times