235 research outputs found

    Volume penalization for inhomogeneous Neumann boundary conditions modeling scalar flux in complicated geometry

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    We develop a volume penalization method for inhomogeneous Neumann boundary conditions, generalizing the flux-based volume penalization method for homogeneous Neumann boundary condition proposed by Kadoch et al. [J. Comput. Phys. 231 (2012) 4365]. The generalized method allows us to model scalar flux through walls in geometries of complex shape using simple, e.g. Cartesian, domains for solving the governing equations. We examine the properties of the method, by considering a one-dimensional Poisson equation with different Neumann boundary conditions. The penalized Laplace operator is discretized by second order central finite-differences and interpolation. The discretization and penalization errors are thus assessed for several test problems. Convergence properties of the discretized operator and the solution of the penalized equation are analyzed. The generalized method is then applied to an advection-diffusion equation coupled with the Navier-Stokes equations in an annular domain which is immersed in a square domain. The application is verified by numerical simulation of steady free convection in a concentric annulus heated through the inner cylinder surface using an extended square domain.Comment: 32 pages, 19 figure

    Unprecedented High Throughput Titration by Feedback-Based and Subsequent Fixed Triangular Wave-Controlled Flow Ratiometry and Its Application to Quantification of Japanese Pharmacopoeia Drugs

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    Throughput rate of flow ratiometric titration has further been enhanced by shortening the lag time from the confluence of solutions upstream to the sensing of signal downstream and by optimizing analytical parameters. Feedback-based upward and downward scans of titrand/titrant flow ratio were repeated in order to offset the effect of the lag time and thus to locate the equivalence point. Subsequent faster fixed triangular wave-controlled scans in narrower range further increased the throughput rate. Analytical parameters such as scan rate and scan range were optimized. Maximally, 46.9 titrations/min was realized with reasonable precision (RSD = 1.79%). Applicability of the method to the quantitation of the Japanese Pharmacopoeia drugs (furosemide, isoniazid and prochlorperazine maleate) was verified, where the latter two drugs were determined by nonaqueous titrations

    COVID-19 and the Political Economy of the “September School Year Start” in Japan: Overlooked Victims and Foregone Revenues

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    In response to the COVID-19 pandemic, a“September School Year Start”has become a central topic of discussion in Japan. While the pros and cons of changing a conventional academic calendar have been raised, two important aspects have been largely disregarded: foregone earnings of new graduates and relevant tax revenues. We therefore analyse national statistics on the number of new graduates as overlooked victims and their expected monthly wages in conjunction with tax payment, revealing that a September Start would force new graduates to give up approximately 715.7 billion yen, which leads to 87.6 billion yen foregone tax revenues for the government. This means both individuals and the society would lose a certain amount of financial resources by merely introducing a September Start. Considering other policy options are available should national budgets equivalent to foregone tax revenues be mobilised, it is essential for policy makers to examine cost-benefit of both a September Start and alternatives so that they make a sound decision. Although the primary focus of this article is on a September Start and its consequences, the said approach with close attention to scientific evidence rather than abstract notions is now required for the effective education policy-making and beyond

    遺伝子組み換え食品に関する日本の消費者意識に関する国際比較

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    BACKGROUND: Reports of food-related incidents, such as cows infected with bovine spongiform encephalopathy (2001) and the Fukushima nuclear accident (2011), engendered significant fear among Japanese consumers and led to multiple farmer suicides, even when no actual health damage occurred. The growing availability of genetically modified (GM) food is occurring against this backdrop of concern about food safety. Consumers need information to assess risk and make informed purchasing decisions. However, we lack a clear picture of Japanese consumer perceptions of GM food. OBJECTIVE: This study aims to understand Japanese consumer perceptions of GM food for risk communication. Consumer perceptions of GM food were compared among 4 nations. METHODS: A Web-based survey was conducted in Japan, the United States, the United Kingdom, and France. Participants were asked about demographics, fear of health hazards, resistance to GM and breeding-improved products, perception of GM technology and products, and willingness to pay. Multiple linear regression analyses were conducted, as were t tests on dichotomous variables, and 1-way analysis of variance and post hoc tests. RESULTS: Of 1812 individuals who agreed to participate, 1705 (94%) responded: 457 from Japan and 416 each from France, the United States, and the United Kingdom. The male/female and age group ratios were all about even. Some resistance to GM food was seen in all countries in this study. France showed the strongest resistance (P<.001), followed by Japan, which had stronger resistance than the United States and the United Kingdom (P<.001). Overall, females, people in their 60s and older, and those without higher education showed the greatest resistance to GM food. Japan showed stronger fear of food hazards than other nations (P<.001, odds ratio=2.408, CI: 1.614-3.594); Japanese and French respondents showed the strongest fear of hazards from GM food (P<.001). Regarding perceptions of GM technology and products, consumers in nations other than Japan would accept GM food if it were appropriately explained, they were provided with scientific data supporting its safety, and they understood that all food carries some risk. However, Japanese consumers tended to accept GM technology but rejected its application to food (P<.001). Of those willing to purchase GM food, consumers in Japan required a discount of 30% compared with about 20% in other nations. CONCLUSION: All consumers in our study showed resistance to GM food. Although no health hazards are known, respondents in Japan and France strongly recognized GM food as a health risk. Price discounts of 30% and GM technology may be communication cues to start discussions about GM food among Japanese consumers. Although education-only risk communication generally is not effective, such an approach may work in Japan to help consumers better understand GM technology and, eventually, GM food. The gap between accepting GM technology and rejecting its application to food should be explored further.博士(医学)・乙第1390号・平成29年3月15日Copyright © Keiko Komoto, Sawako Okamoto, Miki Hamada, Naoya Obana, Mami Samori, Tomoaki Imamura. Originally published in the Interactive Journal of Medical Research (http://www.i-jmr.org/), 29.08.2016. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Interactive Journal of Medical Research, is properly cited. The complete bibliographic information, a link to the original publication on http://www.i-jmr.org/, as well as this copyright and license information must be included

    The origin of infra-slow oscillations of oxygenated hemoglobin observed in functional near-infrared spectroscopy

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    There is increasing interest in the intrinsic activity of the resting brain, especially the activity slower than 0.1Hz (i.e., low-frequency oscillations, or LFOs). To investigate the origin of LFOs observed in functional near-infrared spectroscopy (fNIRS), we recorded multichannel fNIRS and electroencephalography (EEG) from the frontal cortex of 11 healthy young volunteers in the resting state. Electrocardiography (ECG), electro-oculography and respiration were also measured. Synchronous oscillations of oxy-hemoglobin (oxy-Hb) around 1.0Hz were detected in all fNIRS channels, and their frequency was consistent with a peak frequency of ECG, suggesting the changes of cerebral blood flow due to heart beats. In addition, oxy-Hb oscillations around 0.1Hz (i.e., LFOs) appeared in the fNIRS. The channels where LFOs appeared differed among the subjects, and the LFOs appeared or disappeared even in the same fNIRS channels. The appearance of LFOs in fNIRS channels was significantly higher when the LFOs appeared on the EEG in the adjacent EEG electrodes compared to when LFOs did not appear on EEG. The amplitude and coherence (synchronicity) of the LFOs were increased by changing the subjects' position from dorsal to the sitting position in both fNIRS and EEG, and the coherence in particular was increased in the homologous fNIRS channels on the bilateral hemispheres. These results suggest that LFOs of oxy-Hb couple with resting-state EEG activity

    Helping-Like Behaviour in Mice Towards Conspecifics Constrained Inside Tubes

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    Prosocial behaviour, including helping behaviour, benefits others. Recently, helping-like behaviour has been observed in rats, but whether it is oriented towards rescue, social contact with others, or other goals remains unclear. Therefore, we investigated whether helping-like behaviour could be observed in mice similar to that in rats. Because mice are social animals widely used in neuroscience, the discovery of helping-like behaviour in mice would be valuable in clarifying the psychological and biological mechanisms underlying pro-sociability. We constrained mice inside tubes. Subject mice were allowed to move freely in cages with tubes containing constrained conspecifics. The subject mice released both cagemates and stranger mice but did not engage in opening empty tubes. Furthermore, the same behaviour was observed under aversive conditions and with anesthetised conspecifics. Interestingly, hungry mice opened the tubes containing food before engaging in tube-opening behaviour to free constrained conspecifics. Mice showed equal preferences for constrained and freely moving conspecifics. We demonstrated for the first time that mice show tube-opening behaviour. Furthermore, we partly clarified the purpose and motivation of this behaviour. An effective mouse model for helping-like behaviour would facilitate research on the mechanisms underlying prosocial behaviour

    Layer-specific expression of extracellular matrix molecules in the mouse somatosensory and piriform cortices

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    In the developing central nervous system (CNS), extracellular matrix (ECM) molecules have regulating roles such as in brain development, neural-circuit maturation, and synaptic-function control. However, excluding the perineuronal net (PNN) area, the distribution, constituent elements, and expression level of granular ECM molecules (diffuse ECM) present in the mature CNS remain unclear. Diffuse ECM molecules in the CNS share the components of PNNs and are likely functional. As cortical functions are greatly region-dependent, we hypothesized that ECM molecules would differ in distribution, expression level, and components in a region- and layer-dependent manner. We examined the layer-specific expression of several chondroitin sulfate proteoglycans (aggrecan, neurocan, and brevican), tenascin-R, Wisteria floribunda agglutinin (WFA)-positive molecules, hyaluronic acid, and link protein in the somatosensory and piriform cortices of mature mice. Furthermore, we investigated expression changes in WFA-positive molecules due to aging. In the somatosensory cortex, PNN density was particularly high at layer 4 (L4), but not all diffuse ECM molecules were highly expressed at L4 compared to the other layers. There was almost no change in tenascin-R and hyaluronic acid in any somatosensory-cortex layer. Neurocan showed high expression in L1 of the somatosensory cortex. In the piriform cortex, many ECM molecules showed higher expression in L1 than in the other layers. However, hyaluronic acid showed high expression in deep layers. Here, we clarified that ECM molecules differ in constituent elements and expression in a region- and layer-dependent manner. Region-specific expression of ECM molecules is possibly related to functions such as region-specific plasticity and vulnerability
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