ニホンゴ ノウリョク シケン ノ インシ ブンセキテキ ケントウ

日本語能力試験では、年度ごとに日本語教育的、心理測定理論的な視点から分析・評価がなされ『日本語能力試験分析評価に関する報告書』として発表されてきたが、既存の類別の枠組みを越えた因子分析的な検討は実施されていない。そのため、既存の類別の枠組みを越えてさらに詳細な因子分析的検討を行なうことが必要である。また、漢字の能力が習得に影響すると考えられる中上級レベルにおいて、非漢字圏受験者の因子構造にどのような特徴があるかを検討する必要がある。そこで、本研究では日本語能力試験について、次の3つの点から検討することを目的とする。 (1)1級から4級の因子構造を比較する。 (2)各級ごとに既存の類別を越えた因子構造を探る。 (3)1、2級の非漢字圏受験者の因子構造の特徴を検討する。その結果、本研究では以下のような結果が得られた。 (1)各級の全類の項目を因子分析した結果、4級から1級にかけて日本語の能力水準が上がるにしたがって因子数が増加する。 (2)各級の「文字」「語彙」「文法」項目を因子分析した結果、比較的高い一因子性を示す。 (3)非漢字圏受験者について因子分析した結果、大枠では因子構造に違いがないが、「語彙」項目に違いが見られた

The 2018 Hokkaido Eastern Iburi earthquake (M-JMA=6.7) was triggered by a strike-slip faulting in a stepover segment: insights from the aftershock distribution and the focal mechanism solution of the main shock

The Hokkaido Eastern Iburi earthquake (MJMA = 6.7) occurred on September 6, 2018, in the Hokkaido corner region where the Kurile and northeastern Japan island arcs meet. We relocated aftershocks of this intraplate earthquake immediately after the main shock by using data from a permanent local seismic network and found that aftershock depths were concentrated from 20 to 40 km, which is extraordinarily deep compared with other shallow intraplate earthquakes in the inland area of Honshu and Kyushu, Japan. Further, we found that the aftershock area consists of three segments. The first segment is located in the northern part of the aftershock area, the second segment lies in the southern part, and the third segment forms a stepover between the other two segments. The hypocenter of the main shock, from which the rupture initiated, is located on the stepover segment. The centroid moment tensor solution for the main shock indicates a reverse faulting, whereas the focal mechanism solution determined by using the first-motion polarity of the P wave indicates strike-slip faulting. To explain this discrepancy qualitatively, we present a model in which the rupture started as a small strike-slip fault in the stepover segment of the aftershock area, followed by two large reverse faulting ruptures in the northern and southern segments

Rhodopsin-bestrophin fusion proteins from unicellular algae form gigantic pentameric ion channels

Many organisms sense light using rhodopsins, photoreceptive proteins containing a retinal chromophore. Here we report the discovery, structure and biophysical characterization of bestrhodopsins, a microbial rhodopsin subfamily from marine unicellular algae, in which one rhodopsin domain of eight transmembrane helices or, more often, two such domains in tandem, are C-terminally fused to a bestrophin channel. Cryo-EM analysis of a rhodopsin-rhodopsin-bestrophin fusion revealed that it forms a pentameric megacomplex (~700 kDa) with five rhodopsin pseudodimers surrounding the channel in the center. Bestrhodopsins are metastable and undergo photoconversion between red- and green-absorbing or green- and UVA-absorbing forms in the different variants. The retinal chromophore, in a unique binding pocket, photoisomerizes from all-trans to 11-cis form. Heterologously expressed bestrhodopsin behaves as a light-modulated anion channel

Focal mechanisms and the stress field in the aftershock area of the 2018 Hokkaido Eastern Iburi earthquake (M-JMA=6.7)

The tectonic stress field was investigated in and around the aftershock area of the Hokkaido Eastern Iburi earthquake (M-JMA = 6.7) occurred on 6 September 2018. We deployed 26 temporary seismic stations in the aftershock area for approximately 2 months and located 1785 aftershocks precisely. Among these aftershocks, 894 focal mechanism solutions were determined using the first-motion polarity of P wave from the temporary observation and the permanent seismic networks of Hokkaido University, Japan Meteorological Agency (JMA), and High Sensitivity Seismograph Network Japan (Hi-net). We found that (1) the reverse faulting and the strike-slip faulting are dominant in the aftershock area, (2) the average trend of P- and T-axes is 78 degrees +/- 33 degrees and 352 degrees +/- 51 degrees, respectively, and (3) the average plunge of P- and T-axes is 25 degrees +/- 16 degrees and 44 degrees +/- 20 degrees, respectively: the P-axis is close to be horizontal and the T-axis is more vertical than the average of the P-axes. We applied a stress inversion method to the focal mechanism solutions to estimate a stress field in the aftershock area. As a result, we found that the reverse fault type stress field is dominant in the aftershock area. An axis of the maximum principal stress (sigma(1)) has the trend of 72 degrees +/- 7 degrees and the dipping eastward of 19 degrees +/- 4 degrees and an axis of the intermediate principal stress (sigma(2)) has the trend of 131 degrees +/- 73 degrees and the dipping southward of 10 degrees +/- 9 degrees, indicating that both of sigma(1)- and sigma(2)-axes are close to be horizontal. An axis of the minimum principal stress (sigma(3)) has the dipping westward of 67 degrees +/- 6 degrees that is close to be vertical. The results strongly suggest that the reverse-fault-type stress field is predominant as an average over the aftershock area which is in the western boundary of the Hidaka Collision Zone. The average of the stress ratio R = (sigma(1) - sigma(2))/(sigma(1) - sigma(3)) is 0.61 +/- 0.13 in the whole aftershock area. Although not statistically significant, we suggest that R decreases systematically as the depth is getting deep, which is modeled by a quadratic polynomial of depth