282 research outputs found

    Early Years Students’ Relationships with Mathematics

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    Early years mathematics experiences have been shown to be a significant predictor for students’ school readiness and future mathematics achievement. Previous research also indicates an important connection between emotion and mathematics learning. How do students in early years education in Alberta describe their emotional relationship with mathematics? This article documents the findings of our research focusing on Kindergarten to Grade 2 students. Our analysis showed that many students in the early years, including those at the Kindergarten level, recognized what is considered to be mathematics but mainly associated mathematics with number and numerical operations. The majority of these students reported positive relationships with mathematics, though some described negative relationships with school mathematics learning.Les expĂ©riences prĂ©scolaires avec les mathĂ©matiques se sont avĂ©rĂ©es ĂȘtre des prĂ©dicteurs importants de la maturitĂ© scolaire des jeunes enfants et de leur rendement en mathĂ©matiques Ă  l’avenir. La recherche a Ă©galement rĂ©vĂ©lĂ© un lien important entre les Ă©motions et l’apprentissage des mathĂ©matiques. Comment les jeunes Albertains dĂ©crivent-ils leur relation Ă©motionnelle avec les mathĂ©matiques? Cet article explique les rĂ©sultats d’une recherche portant sur des Ă©lĂšves de la maternelle Ă  la 2e annĂ©e. Notre analyse dĂ©montre que plusieurs jeunes Ă©lĂšves, y compris ceux de la maternelle, ont reconnu ce qui est considĂ©rĂ© comme Ă©tant les mathĂ©matiques, mais que pour eux, les mathĂ©matiques sont surtout liĂ©s aux chiffres et aux opĂ©rations numĂ©riques. Alors que la plupart de ces Ă©lĂšves ont indiquĂ© qu’ils avaient un rapport positif avec les mathĂ©matiques, certains ont dĂ©crit des liens nĂ©gatifs par rapport Ă  l’apprentissage des mathĂ©matiques Ă  l’école.

    First-principles study on the intermediate compounds of LiBH4_4

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    We report the results of the first-principles calculation on the intermediate compounds of LiBH4_4. The stability of LiB3_3H8_8 and Li2_2Bn_nHn(n=5−12)_n (n=5-12) has been examined with the ultrasoft pseudopotential method based on the density functional theory. Theoretical prediction has suggested that monoclinic Li2_2B12_{12}H12_{12} is the most stable among the candidate materials. We propose the following hydriding/dehydriding process of LiBH4_4 via this intermediate compound : LiBH4↔1/12_4 \leftrightarrow {1/12}Li2_{2}B12_{12}H12+5/6_{12} + {5/6} LiH +13/12+ {13/12}H2↔_2 \leftrightarrow LiH ++ B +3/2+ {3/2} H2_2. The hydrogen content and enthalpy of the first reaction are estimated to be 10 mass% and 56 kJ/mol H2_2, respectively, and those of the second reaction are 4 mass% and 125 kJ/mol H2_2. They are in good agreement with experimental results of the thermal desorption spectra of LiBH4_4. Our calculation has predicted that the bending modes for the Γ\Gamma-phonon frequencies of monoclinic Li2_2B12_{12}H12_{12} are lower than that of LiBH4_4, while stretching modes are higher. These results are very useful for the experimental search and identification of possible intermediate compounds.Comment: 7 pages, 5 figures, submitted to PR

    Fracture origin and crack propagation of CAD/CAM composite crowns by combining of in vitro and in silico approaches

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    Purpose: Fractographic analysis has been used to investigate the fracture behavior of Computer-aided design/computer-aided manufacturing (CAD/CAM) composite crowns by subjecting them to compression tests. However, it is difficult to investigate details of the fracture, including its initiation and propagation, using in vitro tests. The aim of this study was to determine the fracture origins and the order of crack initiation of CAD/CAM composite crowns using in silico nonlinear dynamic finite element analysis (FEA). Material and methods: The following materials were used: Cerasmart (CS), Katana Avencia Block (KA), and Shofu Block HC (HC) as CAD/CAM crowns, Panavia SA Cement Plus (SA) as a luting material, and Clearfil DC Core Plus (DC) as an abutment. The elastic moduli and fracture strain of each material were obtained from the stress–strain curve of in vitro three-point bending tests. The fracture origins and order of crack initiation of the materials were determined by in silico nonlinear dynamic compression analysis. Load-displacement curves were statistically compared with the results of the in vitro compression tests (Pearson's correlation test, α = 0.05). Results: The nonlinear dynamic FEA demonstrated that crack initiation was primarily observed near the lingual side of the CAD/CAM crowns and immediately propagated to the central fossa. The models were fractured following the in vitro fracture strains, showing the same order for the products tested (CS/KA/HC, SA, and DC). Load-displacement curves with the use of CS, KA, and HC were significantly correlated to the corresponding in vitro compression tests results (CS: r = 0.985, p < 0.05, KA: r = 0.987, p < 0.05, and HC: r = 0.997, p < 0.05). Conclusions: The in silico model established in this study clarified the crack initiation of the CAD/CAM composite crowns and the order of crack initiation among the investigated products, suggesting that the present approach is useful for analyzing the fracture behavior of CAD/CAM composite crowns in detail.Yamaguchi S., Katsumoto Y., Hayashi K., et al. Fracture origin and crack propagation of CAD/CAM composite crowns by combining of in vitro and in silico approaches. Journal of the Mechanical Behavior of Biomedical Materials 112, 104083 (2020); https://doi.org/10.1016/j.jmbbm.2020.104083

    The Japanese model in retrospective : industrial strategies, corporate Japan and the 'hollowing out' of Japanese industry

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    This article provides a retrospective look at the Japanese model of industrial development. This model combined an institutional approach to production based around the Japanese Firm (Aoki's, J-mode) and strategic state intervention in industry by the Japanese Ministry of International Trade and Industry (MITI). For a long period, the alignment of state and corporate interests appeared to match the wider public interest as the Japanese economy prospered. However, since the early 1990s, the global ambitions of the corporate sector have contributed to a significant 'hollowing out' of Japan's industrial base. As the world today looks for a new direction in economic management, we suggest the Japanese model provides policy-makers with a salutary lesson in tying the wider public interest with those of the corporate sector

    Observation of gigantic spin conversion anisotropy in bismuth

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    Whilst the g-factor can be anisotropic due to the spin-orbit interaction (SOI), its existence in solids cannot be simply asserted from a band structure, which hinders progress on studies from such the viewpoints. The g-factor in bismuth (Bi) is largely anisotropic; especially for holes at T-point, the g-factor perpendicular to the trigonal axis is negligibly small (< 0.112), whereas the g-factor along the trigonal axis is very large (62.7). We clarified in this work that the large g- factor anisotropy gives rise to the gigantic spin conversion anisotropy in Bi from experimental and theoretical approaches. Spin-torque ferromagnetic resonance was applied to estimate the spin conversion efficiency in rhombohedral (110) Bi to be 17%, which is unlike the negligibly small efficiency in Bi(111). Harmonic Hall measurements supports the large spin conversion efficiency in Bi(110). This is the first observation of gigantic spin conversion anisotropy as the clear manifestation of the g-factor anisotropy. Beyond the emblematic case of Bi, our study unveiled the significance of the g-factor anisotropy in condensed-matter physics and can pave a pathway toward establishing novel spin physics under g-factor control.Comment: 28 pages, 7 figure

    Autonomic function measurements for evaluating fatigue and quality of life in patients with breast cancer undergoing radiation therapy: a prospective longitudinal study

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    Background: Fatigue during radiation therapy in women with breast cancer can decrease quality of life (QOL), yet it is often underestimated and needs to be evaluated objectively. This longitudinal study aimed to evaluate fatigue and QOL of women with breast cancer undergoing radiotherapy with a simple autonomic function measurement. Methods: Women with breast cancer who underwent postoperative radiotherapy in eight cancer care hospitals in Chubu and Kinki regions in Japan were recruited between October 2021 and June 2022. The women underwent a self-administered questionnaire that included the Cancer Fatigue Scale (CFS) and the Short Form-8 Health Survey (SF-8) and an autonomic nervous function measurement using a simple, non-invasive device before (T0, baseline), mid (T1), and at the end (T2) of treatment. Results: The 57 women showed similar trends, with CFS scores and log LF/HF ratio being the highest at T0 and significantly decreasing at T1 (both p < 0.05). The log LF/HF trends differed between those with high and low baseline log LF/HF values. Women with mental component summary (MCS) score improvement (T0 to T2) had the highest log LF/HF ratio at T0 and had significantly lower log LF/HF values at T1 and T2 than at T0 (p < 0.01 and p < 0.05, respectively). The change of (⊿) MCS from T0 to T1 was negatively correlated with ⊿log LF/HF from T0 to T1 (r = − 0.36, p < 0.01). Conclusions: Measurement of autonomic nerve function with a simple device is useful for objective fatigue assessment during radiotherapy. Psychological support is important as improvement in mental health helps improve autonomic nerve function and, in turn, fatigue.Aoki M., Kuratsune H., Yamamoto S., et al. Autonomic function measurements for evaluating fatigue and quality of life in patients with breast cancer undergoing radiation therapy: a prospective longitudinal study. Radiation Oncology 18, 171 (2023); https://doi.org/10.1186/S13014-023-02362-W

    Symptomatic small schwannoma is a risk factor for surgical complications and correlates with difficulty of enucleation

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    Postoperative neurological deficits of schwannomas are the complications that we want to avoid most. Predicting postoperative neurological deficits is crucial; however, the correlation between preoperative symptoms and neurological findings with postoperative neurological complications has not yet been completely clarified. Here we analyzed the risk factors for postoperative neurological complications. The study included 131 tumors from 107 patients histologically confirmed as schwannomas, which developed in the extremities and trunk without spinal cord involvement. The correlation between clinical findings and postoperative complications were statistically analyzed. One-hundred three tumors (78.6 %) had the preoperative neurological symptoms; these symptoms were detected in 93.3 % of small tumors (<4 cm3). We defined it as follows about the anatomical location of schwannomas. One is “central type” that normal nerve bundles widely splayed over the tumor’s capsule (tumor located in the central region of the nerve). Another is “peripheral type” that easy to enucleate without neurolysis (tumor located in the peripheral region of the nerve). Static analysis showed a significant difference in the Tinel sign, numbness, and postoperative neurological deficits (p = 0.04, 0.006, p < 0.001, respectively). Twenty-one cases (16.0 %) showed new postoperative neurological symptoms, including numbness in 12 cases, dysesthesia in three cases, pain in three cases, and slight motor palsy in two cases. In statistical analysis, small tumors (<4 cm3) significantly correlated with Tinel sign (p < 0.001), and was marginally significant with postoperative neurological deficits (p = 0.05). Moreover, small tumors (<4 cm3) accompanying numbness preoperatively significantly correlated with postoperative neurological deficits (p = 0.04). Small (<4 cm3) tumors significantly correlated with the preoperative neurological symptoms. Those tumors accompanying numbness also significantly correlated with the difficulty of the enucleation and postoperative neurological deficits. These findings will help to predict the neurological complication. © 2015, Abe et al
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