Magma Plumbing System at Izu-Oshima Volcano, Japan: Constraints From Petrological and Geochemical Analyses

The Izu-Oshima volcano is one of the most active volcanoes in Japan, and has generated relatively large-scale eruptions every 30–40 years for the past 200 years. As more than 30 years have passed since the last eruptions in 1986–87, volcanic activity is expected to resume in the near future. To help elucidate the current and future state of the volcano’s magma system, the temporal evolution of the recent magma plumbing system was investigated through a petrological and geochemical analysis of its basaltic lavas and pyroclastics (<∼53 wt.% of SiO2) that were erupted during the last ∼1.5 kyr. The basaltic products have variable phenocryst contents, ranging from ∼0 to ∼20 vol.%, and phenocryst-bearing samples commonly contain plagioclase, orthopyroxene, and clinopyroxene phenocrysts. The whole-rock compositions are significantly scattered in the Harker variation diagrams, suggesting that the compositional diversity was established by at least two independent magmatic processes. The application of principal component analysis on the whole-rock major element data suggests that one magmatic process was crystal fractionation of crystal-poor magmas, and the other process was either plagioclase accumulation or mixing of plagioclase-rich magmas. Based on this observation, and combined with the petrological analysis and previous geophysical studies, we propose that aphyric magmas, stored in an 8–10 km-deep magma chamber, progressively differentiated over time from the 7th to 20th century. Furthermore, the compositional variations in basalts resulted from the mixing of the differentiating aphyric magmas with variable proportions of porphyritic magmas derived from a 13–18 km-deep magma chamber. Because recent eruptions have been triggered by the ascent of porphyritic magma from the 13–18 km-deep magma chamber, and its injection into the 8–10 km-deep magma chamber, it is important to monitor the deeper magma chamber to predict future volcanic activity

1,5-Dicyano­anthraquinone

The complete mol­ecule of the title compound, C16H6N2O2, which is generated by a crystallographic inversion centre, is almost planar (r.m.s. deviation = 0.04 Å). In the crystal, adjacent mol­ecules are stacked along the a axis, with a shortest centroid–centroid separation of 3.826 (2) Å

Rheology of magmas with bimodal crystal size and shape distributions: insights from analog experiments

Magmas in volcanic conduits commonly contain microlites in association with preexisting phenocrysts, as often indicated by volcanic rock textures. In this study, we present two different experiments that inves- tigate the flow behavior of these bidisperse systems. In the first experiments, rotational rheometric methods are used to determine the rheology of monodisperse and polydisperse suspensions consisting of smaller, prolate particles (microlites) and larger, equant particles (phenocrysts) in a bubble‐free Newtonian liquid (silicate melt). Our data show that increasing the relative proportion of prolate microlites to equant pheno- crysts in a magma at constant total particle content can increase the relative viscosity by up to three orders of magnitude. Consequently, the rheological effect of particles in magmas cannot be modeled by assuming a monodisperse population of particles. We propose a new model that uses interpolated parameters based on the relative proportions of small and large particles and produces a considerably improved fit to the data than earlier models. In a second series of experiments we investigate the textures produced by shearing bimodal suspensions in gradually solidifying epoxy resin in a concentric cylinder setup. The resulting textures show the prolate particles are aligned with the flow lines and spherical particles are found in well‐organized strings, with sphere‐depleted shear bands in high‐shear regions. These observations may explain the measured variation in the shear thinning and yield stress behavior with increasing solid fraction and particle aspect ratio. The implications for magma flow are discussed, and rheological results and tex- tural observations are compared with observations on natural samples

訪問看護の専門性を支える経験についての一考察 : 熟練訪問看護師へのインタビューより

訪問看護の時代を切り拓いた看護職の専門性が、どのような経験の積み重ねの中で形成されてきたのかを明らかにすることを目的に、熟練訪問看護師にインタビューを行った。その結果、市町村での訪問看護による住民との関わりの中で、多くのうちのめされる経験をしながら訪問看護の本質をつかんでいったこと、さらに、訪問看護ステーションの開設では社会的認知に苦労したものの、訪問看護の醍醐味を実感したこと、所長として職員や経営を戦略的に育て訪問看護を極めた自負のもと、新たな挑戦として自らの訪問看護ステーションを起業したこと、現在は看護職の誇りを持って、全体性と先見性を意識した次世代につなぐ訪問看護を目指すというストーリーが明らかとなった。A氏の訪問看護の専門性は、反省的実践家モデルの中で形成され、生成継承性の高さを特徴としていた

島根県における旧保健婦養成の足跡

島根県における旧保健婦養成所卒業生会による「草わけの保健婦養成」には、養成所時代のさまざまな記録と共に卒業生を対象としたアンケート結果が掲載されている。一期生は、卒業期における業務内容として、乳幼児や結核患者の家庭訪問、共同炊事・農繁期託児所指導、地域への保健婦活動のアピールを挙げている。地域住民に保健婦の仕事を説明し、分かってもらうことの難しさ、そして何も土台がない所に新しいものを創り上げることの難しさは現代にない苦労の連続であったと推察される。具体的な状況の記録は少ないが、保健婦活動の手記や当時の新聞記事を手がかりに、家庭訪問、農繁期託児所、保健婦劇による保健婦活動のアピール、研究発表等について資料の解説を試みた

島根県立看護短期大学・看護学科における1997年度の地域看護実習と今後の課題

平成9年度より改正された新カリキュラムに対応した地域看護実習を終了した本学第1期生について、現状と今後のよりよい実習のあり方を検討した。検討した内容は、学生の実習目標に対する自己評価、感想・考察、実習内容や教員評価などの関係である。その結果、地域看護実習の実習場所2カ所の教員評価は有意（P<0.01）な正の相関関係を示した。また、実習場所による自己評価には差があり、限られた実習期間や3年過程の看護教育における限界も感じられた。しかし、学生が自由記載で記述した内容をKJ法で分類してみると、多くの学び、気づきを示していた。多くの課題を残した実習ではあったが、担当した教員として確かな学びの手応えを感じている