Acquisition and Assessment of L2 Pronunciation Skills in Japanese Learners

The current paper reviews previous research on the acquisition of Japanese language sounds and pronunciation skills of second-language learners of Japanese, focusing on both segmental and suprasegmental features. We first provide a brief overview of Japanese language sounds. Studies based on comparative analysis of segmental features in Japanese and learners’ native languages are then discussed, followed by a review of recent studies involving a range of techniques, including acoustic analysis, cross-sectional and time-series experimental designs to explore the acquisition process and factors affecting it. In addition, we examine research on the production and perception of Japanese lexical accent, and the relationships between them. Based on this review, we propose that the rhythmic unit, mora, a typologically unique feature of Japanese, presents significant learning challenges for second-language learners, because it affects the perception and production of segmental features such as long and short vowels, double consonants, and syllabic nasals as well as the Japanese lexical accent. Finally, we examine previous research examming second-language learners’ pronunciation skills. We propose that insufficient attention has been paid to this issue, warranting future investigation

セルオートマトンを用いた信号機のある交通流の解析

九州大学応用力学研究所研究集会報告 No.25AO-S2 「非線形波動研究の拡がり」Reports of RIAM Symposium No.25AO-S2 The breadth and depth of nonlinear wave scienceProceedings of a symposium held at Chikushi Campus, Kyushu Universiy, Kasuga, Fukuoka, Japan, October 31 - November 2, 2013本論文では、車の流れを完全非対称単純排他過程(TASEP)、歩行者を離散時間で更新する待ち行列にてモデル化することで、新しい境界条件に従うTASEPモデルを考案する。まず、モデルを用いて交差点における車の流量をモンテカルロシミュレーションにより解析した。結果、歩行者が交差点をふさぐ平均時間を単純に考慮したTASEPモデルと比べ、流量が減少することを発見した。また、平均場近似を用いた数理解析により導いた近似解は、幅広い歩行者流入量の範囲内においてよい近似を見せることを示した。さらに、このモデルに信号機を加えたモデルを考案し、近似解を導出した

Involvement of Propionibacterium acnes in the Augmentation of Lipogenesis in Hamster Sebaceous Glands In Vivo and In Vitro

Propionibacterium acnes is considered to be involved in the aggravation of acne vulgaris, but it remains unclear whether P. acnes directly influences lipogenesis in sebaceous glands. In this study, we showed that a culture medium of P. acnes (acnes-CM) and formalin-killed P. acnes (F-acnes) prepared from P. acnes strains, JCM6473 and JCM6425, intracellularly augmented lipid droplet formation and triacylglycerol (TG) synthesis in undifferentiated and insulin-differentiated hamster sebocytes. Acnes-CM and F-acnes prepared from four clinical P. acnes strains elicited the same lipogenesis augmentation. The augmented TG production resulted from an increase in the diacylglycerol acyltransferase activity. Topical application of acnes-CM to the skin of hamster auricles every day for 4 weeks revealed that sebum accumulation was augmented in sebaceous glands and ducts. Furthermore, both acnes-CM and F-acnes increased the production of 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), a cytochrome P450 (CYP)-linked sebaceous lipogenic factor, in differentiated sebocytes. A CYP inhibitor, SKF-525A, decreased the acnes-CM- and F-acnes-augmented production of TG and 15d-PGJ2. Thus, to our knowledge these results provide previously unreported evidence that P. acnes directly participates in the augmentation of sebaceous lipogenesis through a proposed mechanism in which an increase of 15d-PGJ2 production through the CYP pathway is closely associated with the enhancement of TG production

Vitamin B6 in acute encephalopathy with biphasic seizures and late reduced diffusion

Background The initial presentation of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is indistinguishable from that of complex febrile seizures (FS), which poses a great diagnostic challenge for clinicians. Excitotoxicity is speculated to be the pathogenesis of AESD. Vitamin B6 (VB6) is essential for the biosynthesis of gamma-aminobutyric acid, an inhibitory neurotransmitter. The aim of this study is to investigate our hypothesis that VB6 deficiency in the brain may play a role in AESD. Methods We obtained cerebrospinal fluid (CSF) samples from pediatric patients with AESD after early seizures and those with FS. We measured pyridoxal 5′-phosphate (PLP) and pyridoxal (PL) concentrations in the CSF samples using high-performance liquid chromatography with fluorescence detection. Results The subjects were 5 patients with AESD and 17 patients with FS. Age did not differ significantly between AESD and FS. In AESD, CSF PLP concentration was marginally lower (p = 0.0999) and the PLP-to-PL ratio was significantly (p = 0.0417) reduced compared to those in FS. Conclusions Although it is impossible to conclude that low PLP concentration and PLP-to-PL ratio are causative of AESD, this may be a risk factor for developing AESD. When combined with other markers, this finding may be useful in distinguishing AESD from FS upon initial presentation