279 research outputs found

    Accelerating universe, WEP violation and antihydrogen atoms

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    Apart from the suspected violation of the CPT invariance, we might expect if the measurements of antihydrogen atoms provide testing Weak Equivalence Principle (WEP) in the gravitational phenomena. We start with how its violation can be related to the expected idea of unification of particle physics and gravitation, an attempt beyond the standard theories, including general relativity of Einstein. A particular emphasis will be placed on the issue of an accelerating universe, a rather recent development since nearly 10 years ago, suggesting a strong motivation toward attempts beyond the conventional concepts of the traditional cosmology. We face today's version of the cosmological constant problem. A candidate of the new ingredient appears to be provided by a scalar field, sometimes under the names like quintessence or dark-energy. In this article, we discuss the subject from a point of view of a more theoretical approach based on the scalar-tensor theory of gravitation. By exploiting the concepts of conformal transformations and conformal frames unique to this type of approach, we show that a successful understanding of the observed cosmological acceleration entails an unexpected outcome of breakdown of WEP, which may show up as a distinct behavior between hydrogen and antihydrogen in the gravitational influence, from a further wider perspective including a vector field as well. We intended to introduce most of the new concepts as plainly and briefly as possible, according to the nature of the talk. On the other hand, however, we find it also useful to go into some more details, depending on the interests of individuals among the audience. For a compromise, we decided to add a number of footnotes which were not delivered during the presentation, but might be helpful in the proceedings published later.Comment: 12 pages, 5 figures. Prepared for the Proceedings of the Workshop on Cold Antimatter Plasmas and Application to Fundamental Physics, February 20-22, 2008, Naha, Okinawa, Japan. Due to a technical problem, diagrams in Fig. 4 in the original Proceedings are replaced here by simplified versions. Corrected fi

    Effect of Earth Ground and Environment on Body-Centric Communications in the MHz Band

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    Body area network (BAN) research, which uses the human body as a transmission channel, has recently attracted considerable attention globally. Zimmerman first advocated the idea in 1995. Illustrations of the electric field streamlines around the human body and wearable devices with electrodes were drawn. In the pictures, the electrodes of the wearable devices constitute a closed circuit with the human body and the earth ground. However, analysis of the circuit has not been conducted. In this study, we model the human body shunted to earth ground in a radio anechoic chamber to analyze the electric field strength around it and clarify the effect of earth ground during BAN run time. The results suggest that earth ground has little influence on the human body and wearable devices. Only when the human body is directly grounded, the electric field near the feet area will decrease. The input impedance of the transmitter is approximately the same, and the received open-circuit voltage and current of the receiver are also the same. In addition, we elucidate that stable communications can be established by developing a closed circuit using earth ground as return path. When the external electronic devices and human body are shunted to earth ground, the received open-circuit voltage and current increase

    Molecular Simulation Analysis of the Structure Complex of C2 Domains of DKK Family Members and β-propeller Domains of LRP5/6:Explaining Why DKK3 Does Not Bind to LRP5/6

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    Dickkopf (DKK) proteins interact with low-density lipoprotein receptor-related protein 5/6 (LRP5/6) to modulate WNT signaling. The interaction is mediated by a cysteine-rich domain (C2) in the DKK protein and β-propeller domains (PD) of LRP5/6. However, the third member of the DKK family (DKK3) does not bind to LRP5/6. To determine why DKK3 does not bind to the receptor domains, we performed a molecular modeling simulation study including homology modeling, protein-protein docking and molecular dynamics (MD). The computed affinities (ΔGbinding) between the C2 and PD models were consistent with the previously reported experimental results. The C2 model of DKK3 showed the lowest affinity for PD models. Multiple sequence alignment of C2 domains revealed that the DKK3 genes have a unique 7-amino-acid insertion (L249-E255 in human DKK3) and P258 in a finger loop 1 (FL1). Interestingly, the insertion sequence is evolutionally conserved. MD simulations of high-affinity complex models of C2 and PD showed that FL1 directly interacts with the PD models and stabilizes the complex models. We also built a 7-amino-acid-deletion/P258G mutant model of DKK3C2 and estimated its affinities for the PD models. The affinity for human LRP5PD2 was increased by the substitution (ΔGbinding=-48.9kcal/mol) and the affinity was compatible with that of high-affinity ligands. The results suggested that the lack of affinity between human DKK3 and human LRP5/6 results from: i) insertion of the 7 amino acids, and ii) P258 in human DKK3. The sequence differences thus suggest an explanation for this unique property of DKK3

    米国におけるランドバンクによる空き家・空き地問題対処に関する研究

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    学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 大方 潤一郎, 東京大学教授 小泉 秀樹, 東京大学特任教授 窪田 亜矢, 東京大学准教授 村山 顕人, 阪南大学教授 榎戸 敬介University of Tokyo(東京大学

    Hisao Kitamura\u27s Music Education Theory and His Belief of Life

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    The aim of this study is to give a description of specific character of Hisao Kitamura. As is shown ""Mazushiki Chichi-Eiji Ushio ni Ataete (A Poor Father: To My Baby Ushio)"" and ""Sabishii Tsuma to no Hanashi (A Story of My Lonely Wife)"", retrospective essays published in education magazine ""Kyoiku Bungei"" in 1914, in which he expresses his personal feelings without reserve, Hisao Kitamura strived to live as an art teacher-and this includes teaching of beliefs he gained through a life in poverty-as well as his ideal as a music teacher. The contents of the study are as follows. First, I focus on Kitamura\u27s education of ""musical aesthetic intuition"". Then, I explain Kitamura\u27s personality against backdrop of trend of thought in the Taisho era, which attached great importance to personality. Finally, I reveal a connection between the beliefs he gained through his troubles and suffering in real life and his approach to music education. Kitamura\u27s style as an art teacher-teaching was an inherent part of his life-is a typical example of a teacher in the new education trend of the Taisho period

    The Kurashiki Prehospital Stroke Scale Is a Prehospital Scale That Can Predict Long-Term Outcome of Patients with Acute Cerebral Ischemia

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    Background and Purpose: Our aim was to confirm the clinical relationship between the Kurashiki Prehospital Stroke Scale (KPSS) scored by paramedics and favorable outcomes in patients with modified Rankin scale (mRS) scores of 0–1 assessed 3 months after symptom onset. Methods: We enrolled patients with acute stroke and transient ischemic attack showing symptoms on admission. Paramedics transferred patients to our hospital after estimating stroke severity using the KPSS. After categorizing patients into either the mRS 0–1 group (favorable outcome) or the mRS 2–6 group (no favorable outcome), we compared the background data between the two groups. We assessed KPSS scores predictive of a favorable outcome. Multivariate regression modeling was conducted to identify factors independently associated with a favorable outcome. Results: The study cohort comprised 147 patients with a premorbid status of mRS 0–1: 69 patients (47%) of them were in the mRS 0–1 group and 78 (53%) in the mRS 2–6 group at the follow-up 3 months after symptom onset. The median KPSS score was lower in the mRS 0–1 group than in the mRS 2–6 group (1 vs. 4, p Conclusion: KPSS score <3 apparently presents a reasonable cutoff for predicting a favorable outcome in patients with acute cerebral ischemia

    Relationship between Bilirubin Decreasing Rate "b" and Morbidity in Patients with Obstructive Jaundice

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    In the period from 1970 to 1985, 114 patients on whom secondarily operation for obstructive jaundice has been done were surveyed.In order to determine a good clinical indicator for predicting prognosis, we took total bilirubin level and the bilirubin decreasing rate "b". In the relationship between total bilirubin level and morbidity, no significant difference were noted in the groups of total bilirubin level below 4.9mg/dl, at 5.0-9.9mg/dl, and over 10.0mg/dl. While the rate of complication is estimated to be 25% in the good group classified by "b" value, 33.9% in the fair group and 73.5% in the poor group, respectively. Significant difference between morbidity in the good group and the poor (p<0.01), and in the fair and the poor (p<0.01) were noted. Thus we conclude that the bilirubin decreasing rate "b" is much better clinical indicator than total bilirubin level

    Modulation of Hepatocarcinoma Cell Morphology and Activity by Parylene-C Coating on PDMS

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    BACKGROUND: The ability to understand and locally control the morphogenesis of mammalian cells is a fundamental objective of cell and developmental biology as well as tissue engineering research. We present parylene-C (ParC) deposited on polydimethylsiloxane (PDMS) as a new substratum for in vitro advanced cell culture in the case of Human Hepatocarcinoma (HepG2) cells. PRINCIPAL FINDINGS: Our findings establish that the intrinsic properties of ParC-coated PDMS (ParC/PDMS) influence and modulate initial extracellular matrix (ECM; here, type-I collagen) surface architecture, as compared to non-coated PDMS substratum. Morphological changes induced by the presence of ParC on PDMS were shown to directly affect liver cell metabolic activity and the expression of transmembrane receptors implicated in cell adhesion and cell-cell interaction. These changes were characterized by atomic force microscopy (AFM), which elucidated differences in HepG2 cell adhesion, spreading, and reorganization into two- or three-dimensional structures by neosynthesis of ECM components. Local modulation of cell aggregation was successfully performed using ParC/PDMS micropatterns constructed by simple microfabrication. CONCLUSION/SIGNIFICANCE: We demonstrated for the first time the modulation of HepG2 cells' behavior in relation to the intrinsic physical properties of PDMS and ParC, enabling the local modulation of cell spreading in a 2D or 3D manner by simple microfabrication techniques. This work will provide promising insights into the development of cell-based platforms that have many applications in the field of in vitro liver tissue engineering, pharmacology and therapeutics

    Sensing of Oxygen Concentration in a Microfluidic Device mimicking Liver 3D Microarchitecture

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    International audienceWe designed a microfluidic structure which closely reproduces liver microarchitecture, constraining primary rat hepatocytes at a high density and in three dimensions (3D), and in which a gradient of oxygen can be generated. The device includes an oxygen sensitive membrane that could map the oxygen consumption of hepatocytes. INTRODUCTION Compared to classical two-dimensional cell culture, microfluidic devices or/and 3D culture conditions were evidenced to increase the period of time during which primary hepatocytes retain their functions [1]. Moreover, microfluidic techniques offer the opportunity to mimic the in vivo hepatocyte zonation, by subjecting hepatocytes to oxygen gradients [1-2]. Such oxygen gradients that can be estimated by numerical simulations, were recently experimentally assessed using an oxygen sensitive fluorescent membrane [3]. We proposed to include the oxygen sensitive membrane within a miniaturized fluidic device mimicking several hepatic cords in series, and inducing a gradient of oxygen on those. Moreover each of those hepatic cord units was inducing 3D organization of hepatocytes, due to the 72 µm height of culture chambers in which they can aggregate
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