Localization and Size Estimation of Cylindrical Flaws

In recent years, a number of ultrasonic imaging systems for NDE have been developed. 1,2 These systems are mainly composed of expensive high speed electrical circuits, expensive transducers with a number of elements, and signal processing equipment. However, if the processing of signals concerning flaws is based on phase information, the minimum number of transducer elements is only three in the pitch-catch method. This paper deals with a flaw measurement where only three ultrasonic transducers are used at most for localization and sizing of cylindrical flaws

Metastatic carcinoma of the colon similar to Crohn's disease: a case report.

A 68-year-old Japanese man with a history of linitis plastica carcinoma of the stomach and subsequent gastrectomy 8 years previously presented with lower abdominal pain. Radiological and endoscopic examinations showed multiple submucosal nodular lesions similar to Crohn's disease in the ileocecal area. A firm diagnosis could not be made after initial multiple biopsies. Finally, a submucosal biopsy revealed adenocarcinoma. The ileocecal lesion was diagnosed as a recurrence because of the histological findings, which included mucosal preservation, a similarity with the histologic type of stomach carcinoma, and atypical immunoreactivity for primary colon carcinoma; the lesion was negative for both cytokeratin 7 and cytokeratin 20. In cases where metastatic carcinoma of the colon is suspected, we recommend early consideration of a submucosal biopsy.</p

Diatom assemblages in the surface water of the Indian Sector of the Antarctic Surface Water in summer of 1999/2000

Abundance and species composition of diatom assemblages in surface water of the Indian Sector of the Antarctic Surface Water of the Southern Ocean were examined using samples gathered during the JARE-41 Cruise of the icebreaker Shirase in the summer of 1999/2000. On the westward leg (Leg 1), abundance of the diatom assemblage was geographically rather uniform, while species composition was different geographically in mosaic manner. Dominant species on Leg 1 were the pennate Pseudo-nitzschia spp. and the centric Dactyliosolen tenuijunctus, Chaetoceros sp. cf. dichaeta and Chaetoceros neglectus. On the eastward leg (Leg 2), abundance and species composition were different east and west of 60°E. The community to the west was large in abundance and dominated by D. tenuijunctus, while that to the east was small and dominated by the pennate Fragilariopsis species. These diatom assemblages were grouped into four clusters on Leg 1 and three on Leg 2. Mosaic distribution of the clusters was again evident on Leg 1, while rather simple east-west difference was the case on Leg 2. These geographical variations seem to be affected by local sea ice dynamics

Toward Unlimited Self-Learning Monte Carlo with Annealing Process Using VAE's Implicit Isometricity

Self-learning Monte Carlo (SLMC) methods are recently proposed to accelerate Markov chain Monte Carlo (MCMC) methods by using a machine learning model.With generative models having latent variables, SLMC methods realize efficient Monte Carlo updates with less autocorrelation. However, SLMC methods are difficult to directly apply to multimodal distributions for which training data are difficult to obtain. In this paper, we propose a novel SLMC method called the ``annealing VAE-SLMC" to drastically expand the range of applications. Our VAE-SLMC utilizes a variational autoencoder (VAE) as a generative model to make efficient parallel proposals independent of any previous state by applying the theoretically derived implicit isometricity of the VAE. We combine an adaptive annealing process to the VAE-SLMC, making our method applicable to the cases where obtaining unbiased training data is difficult in practical sense due to slow mixing. We also propose a parallel annealing process and an exchange process between chains to make the annealing operation more precise and efficient. Experiments validate that our method can proficiently obtain unbiased samples from multiple multimodal toy distributions and practical multimodal posterior distributions, which is difficult to achieve with the existing SLMC methods.Comment: 24 pages,12 figure

Supernova Nucleosynthesis and Extremely Metal-Poor Stars

We investigate hydrodynamical and nucleosynthetic properties of the jet-induced explosion of a population III $40M_\odot$ star and compare the abundance patterns of the yields with those of the metal-poor stars. We conclude that (1) the ejection of Fe-peak products and the fallback of unprocessed materials can account for the abundance patterns of the extremely metal-poor (EMP) stars and that (2) the jet-induced explosion with different energy deposition rates can explain the diversity of the abundance patterns of the metal-poor stars. Furthermore, the abundance distribution after the explosion and the angular dependence of the yield are shown for the models with high and low energy deposition rates $\dot{E}_{\rm dep}=120\times10^{51} {\rm ergs s^{-1}}$ and $1.5\times10^{51} {\rm ergs s^{-1}}$. We also find that the peculiar abundance pattern of a Si-deficient metal-poor star HE 1424--0241 can be reproduced by the angle-delimited yield for $\theta=30^\circ-35^\circ$ of the model with $\dot{E}_{\rm dep}=120\times10^{51} {\rm ergs s^{-1}}$.Comment: 6 pages, 3 figures. To appear in "ORIGIN OF MATTER AND EVOLUTION OF GALAXIES: From the Dawn of Universe to the Formation of Solar System", AIP Conf. Proc. 1016 (December 2007, Sapporo), eds. T. Suda, T. Nozawa, et al. (Melville: AIP

An Environment for Acquiring and Sharing Arithmetical Word Problems: For Problems Solved by Specific Solution Methods

To realize effective problem-solving practice, the ILE should have various kinds of problems in a large quantity. However, each ILE prepares the problems individually so far. Therefore, to secure enough problems in the quantity and variety is often difficult. To resolve this issue, we designed and developed an environment on internet, which provides a tool to make arithmetical word problems, and categorizes the problems with XML tags, then, supplies the problems for ILEs or users. In this paper, we introduce the description of problem data based on a problem-solving model for arithmetical word problems. Then, the way to make the problems in the environment is explained. The environment can verify logical structure of the problem, but cannot problem sentence. The verification arid revision of problem sentences are carried out when users use the/ problem. The experimental evaluation of this environment is also reported.本研究の一部は，科研費奨励A(13780292), 電気通信普及財団助成，およぴ人工知能研究振興財団の支援を受けた

Chemical Abundances in the Secondary Star of the Black Hole Binary V4641 Sagittarii (SAX J1819.3-2525)

We report on detailed spectroscopic studies performed for the secondary star in the black hole binary (micro-quasar) V4641 Sgr in order to examine its surface chemical composition and to see if its surface shows any signature of pollution by ejecta from a supernova explosion. High-resolution spectra of V4641 Sgr observed in the quiescent state in the blue-visual region are compared with those of the two bright well-studied B9 stars (14 Cyg and $\nu$ Cap) observed with the same instrument. The effective temperature of V4641 Sgr (10500 $\pm$ 200 K) is estimated from the strengths of He~{\sc i} lines, while its rotational velocity, $\it v$ sin $\it i$ (95 $\pm$ 10 km s${}^{-1}$), is estimated from the profile of the Mg~{\sc ii} line at 4481 \AA. We obtain abundances of 10 elements and find definite over-abundances of N (by 0.8 dex or more) and Na (by 0.8 dex) in V4641 Sgr. From line-by-line comparisons of eight other elements (C, O, Mg, Al, Si, Ti, Cr, and Fe) between V4641 Sgr and the two reference stars, we conclude that there is no apparent difference in the abundances of these elements between V4641 Sgr and the two normal late B-type stars, which have been reported to have solar abundances. An evolutionary model of a massive close binary system has been constructed to explain the abundances observed in V4641 Sgr. The model suggests that the progenitor of the black hole forming supernova was as massive as ~ 35 Msun on the main-sequence and, after becoming a ~ 10 Msun He star, underwent "dark" explosion which ejected only N and Na-rich outer layer of the He star without radioactive $^{56}$Ni.Comment: 13 pages, 14 figures. Accepted for publication in the PASJ: Publications of the Astronomical Society of Japa

Hearing impairment and cognitive function among a community-dwelling population in Japan

<p>Abstract</p> <p>Background</p> <p>Hearing impairment is a prevalent and chronic condition in older people. This study investigated the relationship between cognitive function and hearing impairment in a Japanese population.</p> <p>Methods</p> <p>A pure-tone average (0.5-2.0 kHz) was used to evaluate hearing impairment in 846 participants of the Iwaki Health Promotion Project who were aged at least 50 years old (310 men and 536 women). We also administered the Mini-Mental State Examination (MMSE), the Center for Epidemiologic Studies for Depression (CES-D) scale, Starkstein's apathy scale (AS) and the Short Form Health Survey Version 2 (SF-36v2). A multiple linear regression analysis assessed the association between hearing impairment and mental correlates.</p> <p>Results</p> <p>The overall prevalence of hearing impairment in this study population was 37.7%. The participants with hearing impairment were older and less educated compared to those with no hearing problems. We observed significant differences in the MMSE and AS scores between the mild/moderate to severe groups versus the non-impaired group. After adjusting for age, gender and amount of education, hearing impairment was significantly associated with MMSE and AS scores, but not with CES-D scores. Hearing impairment was significantly related to the social functioning (SF) and role emotional (RE) scores of the SF-36v2.</p> <p>Conclusions</p> <p>Hearing impairment is common among older people and is associated with cognitive impairment, apathy and a poor health-related quality of life. Screening for and correcting hearing impairments might improve the quality of life and functional status of older patients.</p

A Novel Serum-Free Monolayer Culture for Orderly Hematopoietic Differentiation of Human Pluripotent Cells via Mesodermal Progenitors

Elucidating the in vitro differentiation of human embryonic stem (ES) and induced pluripotent stem (iPS) cells is important for understanding both normal and pathological hematopoietic development in vivo. For this purpose, a robust and simple hematopoietic differentiation system that can faithfully trace in vivo hematopoiesis is necessary. In this study, we established a novel serum-free monolayer culture that can trace the in vivo hematopoietic pathway from ES/iPS cells to functional definitive blood cells via mesodermal progenitors. Stepwise tuning of exogenous cytokine cocktails induced the hematopoietic mesodermal progenitors via primitive streak cells. These progenitors were then differentiated into various cell lineages depending on the hematopoietic cytokines present. Moreover, single cell deposition assay revealed that common bipotential hemoangiogenic progenitors were induced in our culture. Our system provides a new, robust, and simple method for investigating the mechanisms of mesodermal and hematopoietic differentiation