90 research outputs found

    The role of graphite layers in gravitational deformation of pelitic schist

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    Deep-seated landslides in pelitic schists are common in many countries, but are poorly investigated and understood. In this study we present the first detailed examination and modelling of landslide mechanisms in these materials. We found that pelitic schist commonly contains black, graphite-rich layers on a scale of millimeters to centimeters thickness that are typically weaker than neighboring layers. By examining microscopic textures in borehole samples obtained from landslide masses of pelitic schist, we find that ductile gravitational shearing commonly occurs within these weaker layers, accompanied by brittle fracture in the surrounding layers. To investigate this mechanisms, we have performed high-precision direct shear tests, using a novel back-pressured shearbox, on artificial rock samples both with and without graphite layers placed between pre-cut shear surfaces. The tests used normal stresses up to 800 kPa (equivalent to 32 m depth of burial). We found that the coefficients of friction for samples with graphite layers embedded in the artificial rock samples (0.30, representing an angle of internal friction of 16.7°) were much lower than those without graphite layers on the pre-cut surface (0.85). The shear strength of the artificial rocks with embedded layers of graphite decreased abruptly with increasing areal extent of the graphite layer along the shear surface, from which it can be inferred that the continuity of a graphite layer in natural pelitic schist has a considerable effect on shear resistance. These results suggest that even comparatively low dip angles of schistosity in pelitic schist could initiate microscopic slip along the graphite-rich layers

    Development of Cross-Curricular Career Education Making Use of Internship in a Middle School : Building Relevance of Students ‘Subjective Leaning, School life, and Social Life

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    キャリア教育として中学校の職場体験活動はほぼすべての学校で実施されている。本稿はその事前指導,事後指導を通して,職場体験と学校で学ぶ教科,学校生活,社会生活を生徒にとって意味あるつながりの構築を目指して行った実践の紹介である。具体的には,教職免許を持つ 6 名の大学院生が,それぞれの専門性を生かして教科の専門性と働くことと生活がつながっていることを,中学校 2 年生の職場体験の事後指導Ⅰとしてポスターセッションで伝えた。事後指導 2 時間目では,生徒は働くことと生活と教科のつながりを可視化するマップを作成して意見交換をした。これらの活動の成果は,生徒が記入した授業の振り返りを分類することで確認した。その結果,授業実践者がねらったつながりに気づいたと思われる記述が多く見られた。中でも多かったのは,将来に備えて今後の勉学や努力したいという趣旨の回答であった。As part of career education, work experience activities are conducted in almost all junior high schools in Japan. This paper introduces a practice that helps students build meaningful connections between subjects learned in school, school life, and social life through guidance provided both before and after work experience activities. Specifically, in the first hour of post-activity instruction for the work experience of second-year students, six graduate students with teaching licenses made use of their respective specialties, combining work with subject specialties and students’ lives through poster sessions. In the second hour, graduate student teachers showed them worksheet which made them visualizes the connection between work, life, and subjects. After working with the worksheet according to their internship work, students discussed their case each other. The results of these activities were confirmed by classifying the lessons reviews written by students. Several descriptions contained the connection that the lesson practitioner had aimed for. The most common answers by the participants included their hope they would make study more for their further and for their satisfied life

    A Case of Typical Carcinoid of the Larynx

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    We report herein a rare case of typical carcinoid occurring primarily in the epiglottis. The patient was a 70-year-old man. On initial examination, a polypoid lesion with irregular surface near the center right-hand side of the laryngeal surface of the epiglottis was observed, and a biopsy was performed. Pathological examination of the specimen suggested the possibility of adenocarcinoma. Surgical excision was performed by means of laryngomicrosurgery. A Weerda-type laryngoscope was used to open the larynx, supplemented by rigid nasal sinus surgery endoscopes, and the right-hand half of the epiglottis were excised was ensured using a CO(2) laser. Postoperative pathological diagnosis was negative for adenocarcinoma and squamous cell cancer; typical carcinoid was diagnosed according to the World Health Organization criteria. Aspiration occurred postoperatively, swallowing training was therefore provided, and the patient was discharged from hospital 2 months after surgery when he was able to eat normally. As of 4 years after surgery, the patient remains under follow-up observation by means of PET-CT and neck, thoracic, and abdominal CT administered at appropriate intervals, but no findings indicating obvious recurrence or metastasis have been observed, and the patient displays good swallowing function

    Possible helimagnetic order in Co4+-containing perovskites Sr1-xCaxCoO3

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    We systematically synthesized perovskite-type oxides Sr1-xCaxCoO3 containing unusually high valence Co4+ ions by a high pressure technique, and investigated the effect of systematic lattice change on the magnetic and electronic properties. As the Ca content x exceeds about 0.6, the structure changes from cubic to orthorhombic, which is supported by the first-principles calculations of enthalpy. Upon the orthorhombic distortion, the ground state remains to be apparently ferromagnetic with a slight drop of the Curie temperature. Importantly, the compounds with x larger than 0.8 show antiferromagnetic behavior with positive Weiss temperatures and nonlinear magnetization curves at lowest temperature, implying that the ground state is noncollinear antiferromagnetic or helimagnetic. Considering the incoherent metallic behavior and the suppression of the electronic specific heat at high x region, the possible emergence of a helimagnetic state in Sr1-xCaxCoO3 is discussed in terms of the band-width narrowing and the double-exchange mechanism with the negative charge transfer energy as well as the spin frustration owing to the next-nearest neighbor interaction.Comment: 13 pages, 4 figure

    Downregulation of Neuronal and Dendritic Connexin36-Made Electrical Synapses Without Glutamatergic Axon Terminals in Spinal Anterior Horn Cells From the Early Stage of Amyotrophic Lateral Sclerosis

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    Connexin36 (Cx36) forms gap junctions between neurons, which are called electrical synapses, enabling adjacent neurons to communicate directly. The participation of chemical synapses in neurodegeneration in amyotrophic lateral sclerosis (ALS) has long been indicated, but it remains unclear whether electrical synapses are involved in the pathogenesis of ALS. We performed extensive immunopathological analyses using mutant superoxide dismutase 1 (SOD1G93A) transgenic mice and their littermates to investigate whether Cx36-made electrical synapses are affected in motor neuron diseases. We found that in the lamina IX of the lumbar spinal cord from wild type mice, about half of the Cx36 puncta existed independently of chemical synapse markers, while the rest coexisted with chemical synapse markers, such as vesicular glutamate transporter 1 (VGLUT1), which is a glutamatergic axon terminal marker, and/or glutamate decarboxylase 65 (GAD65), which is a GABAergic axon terminal marker. Cx36 single or Cx36/GAD65 double positive puncta, but not VGLUT1-containing puncta, were preferentially decreased on neuronal and dendritic surfaces of the anterior horn cells in the early stage of SOD1G93A ALS mice. Moreover, in five human autopsied sporadic ALS cases with bulbar or upper limb onset, Cx36 immunoreactivity was diminished in the proximal dendrites and neuropils of well-preserved large motor neurons in the lumbar anterior horns. These findings suggest that downregulation of neuronal and dendritic Cx36 in the spinal anterior horns commonly occurs from the early stage of hereditary and sporadic ALS. Cx36-made electrical synapses without glutamatergic signaling appear to be more vulnerable than other chemical synapses and electrical synapses with glutamatergic signaling in the early stage of motor neuron degeneration, suggesting involvement of Cx36-made electrical synapses in the pathogenesis of human ALS

    Characteristics of physical activity during beginner-level group tennis lessons and the effect daily activity

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    Kawakami R., Yamakawa S., Konda S., et al. Characteristics of physical activity during beginner-level group tennis lessons and the effect daily activity. Scientific Reports 14, 249 (2024); https://doi.org/10.1038/s41598-023-46843-0.Tennis is a popular leisure sport, and studies have indicated that playing tennis regularly provides many health benefits. We aimed to clarify the characteristics of physical activity during beginner-level group tennis lessons and daily physical activity of the participants. Physical activity was measured using an accelerometer sensor device for four weeks, including the 80-min duration tennis lessons held twice a week. Valid data were categorized for tennis and non-tennis days. The mean physical activity intensity during the tennis lesson was 3.37 METs. The mean ratio of short-bout rest periods to the tennis lesson time in 90 and 120 s was 7% and 4%, respectively. The mean physical activity intensity was significantly higher (p < 0.0001) and the duration of vigorous-intensity physical activity (VPA) was increased in 76% of participants on days with tennis lessons compared to without tennis lessons. Beginner-level tennis lesson has characteristics of less short-bout rest physical activity than previously reported competitive tennis match and increased the duration of VPA in daily activity compared to without tennis lessons, suggesting that beginner-level tennis lessons contribute physical activity of health benefits

    High- and Low-Energy Photoemission Study of Strongly Correlated Au–Ga–Ce Quasicrystal Approximants: Localized 4f Nature and Disorder Effects

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    Nozue G., Fujiwara H., Hamamoto S., et al. High- and Low-Energy Photoemission Study of Strongly Correlated Au–Ga–Ce Quasicrystal Approximants: Localized 4f Nature and Disorder Effects. Journal of the Physical Society of Japan 93(7) 074601, 15 July, 2024; https://doi.org/10.7566/JPSJ.93.074703.We have investigated the electronic structures of Ce-based 1/1 quasicrystal approximants Au₅₉.₂Ga₂₅.₇Ce₁₅.₁ and Au₆₀.₃Ga₂₆.₁Ce₁₃.₆ by hard X-ray photoemission (HAXPES) and high-resolution photoemission spectroscopy. The localized Ce 4f electronic states are revealed for both Au–Ga–Ce approximants. Moreover, disorders in the compounds notably affect their electronic states, which has been detected by the core-level HAXPES. Valence-band photoemission spectra show the slight spectral difference depending on the composition ratio, which can be explained by a rigid-band-like shift

    A Novel Role of the L-Type Calcium Channel α1D Subunit as a Gatekeeper for Intracellular Zinc Signaling: Zinc Wave

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    Recent studies have shown that zinc ion (Zn) can behave as an intracellular signaling molecule. We previously demonstrated that mast cells stimulated through the high-affinity IgE receptor (FcεRI) rapidly release intracellular Zn from the endoplasmic reticulum (ER), and we named this phenomenon the “Zn wave”. However, the molecules responsible for releasing Zn and the roles of the Zn wave were elusive. Here we identified the pore-forming α1 subunit of the Cav1.3 (α1D) L-type calcium channel (LTCC) as the gatekeeper for the Zn wave. LTCC antagonists inhibited the Zn wave, and an agonist was sufficient to induce it. Notably, α1D was mainly localized to the ER rather than the plasma membrane in mast cells, and the Zn wave was impaired by α1D knockdown. We further found that the LTCC-mediated Zn wave positively controlled cytokine gene induction by enhancing the DNA-binding activity of NF- κB. Consistent with this finding, LTCC antagonists inhibited the cytokine-mediated delayed-type allergic reaction in mice without affecting the immediate-type allergic reaction. These findings indicated that the LTCC α1D subunit located on the ER membrane has a novel function as a gatekeeper for the Zn wave, which is involved in regulating NF-κB signaling and the delayed-type allergic reaction
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