638 research outputs found

    Single-photon generation from a neodymium ion in optical fiber at room temperature

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    The realization of single-photon generation is important for implementing various quantum information technologies. The use of rare-earth ions in an optical fiber is a promising single photon generation method due to its ability to operate at room temperature as well as the low cost involved. Neodymium ions are especially interesting because the ions are one of the most commercially affordable rare-earth materials in the current industry. The neodymium ion also has the advantage of having a rich energy level structure, which offers several possible wavelengths for emitted single photons from visible to near-telecommunication wavelengths. In this paper, we experimentally demonstrated single-photon generation using an isolated single neodymium ion in tapered silica fiber at room temperature. Our results have significant implications as a platform for low-cost wavelength-selectable single-photon sources and photonic quantum applications.Comment: 7 pages, 5figure

    Utilizing Moving Vehicles as Sensors for Bridge Condition Screening – A Laboratory Verification

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    Health condition monitoring of bridge structures is attracting considerable attention, conventionally relying on visual inspection, and measurement-based methods that involve sensors installed directly on bridges. In recent years, drive-by monitoring methods that treat moving vehicles as moving sensors have been proposed as alternatives; these methods aim to be lowcost, mobile, and target fast bridge condition screening. In this study, we address the current lack of sufficient experimental verification of such methods. Laboratory experiments were conducted using a test vehicle system equipped with accelerometers in order to verify the practical feasibility of three drive-by methods: (1) bridge-frequency extraction using the Fourier spectrum of a vehicle’s dynamic response, (2) damage detection using the change in a vehicle’s spectral distribution pattern, and (3) roadway surface profile identification

    Selective Translation of the Measles Virus Nucleocapsid mRNA by La Protein

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    Measles, caused by measles virus (MeV) infection, is the leading cause of death in children because of secondary infections attributable to MeV-induced immune suppression. Recently, we have shown that wild-type MeVs induce the suppression of protein synthesis in host cells (referred to as “shutoff”) and that viral mRNAs are preferentially translated under shutoff conditions in infected cells. To determine the mechanism behind the preferential translation of viral mRNA, we focused on the 5′ untranslated region (UTR) of nucleocapsid (N) mRNA. The La/SSB autoantigen (La) was found to specifically bind to an N-5′UTR probe. Recombinant La enhanced the translation of luciferase mRNA containing the N-5′UTR (N-fLuc), and RNA interference of La suppressed N-fLuc translation. Furthermore, recombinant MeV lacking the La-binding motif in the N-5′UTR displayed delayed viral protein synthesis and growth kinetics at an early phase of infection. These results suggest that La induced predominant translation of N mRNA via binding to its 5′UTR under shutoff conditions. This is the first report on a cellular factor that specifically regulates paramyxovirus mRNA translation

    X-ray structure of Galdieria Rubisco complexed with one sulfate ion per active site

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    AbstractRibulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the reactions of carboxylation and oxygenation of ribulose-1,5-bisphosphate. These reactions require that the active site should be closed by a flexible loop (loop 6) of the large subunit. Rubisco from a red alga, Galdieria partita, has the highest specificity for carboxylation reaction among the Rubiscos hitherto reported. The crystal structure of unactivated Galdieria Rubisco has been determined at 2.6 Å resolution. The electron density map reveals that a sulfate binds only to the P1 anion-binding site of the active site and the loop 6 is closed. Galdieria Rubisco has a unique hydrogen bond between the main chain oxygen of Val332 on the loop 6 and the ϵ-amino group of Gln386 of the same large subunit. This interaction is likely to be crucial to understanding for stabilizing the loop 6 in the closed state and to making a higher affinity for anionic ligands

    Plausible phosphoenolpyruvate binding site revealed by 2.6 Å structure of Mn2+-bound phosphoenolpyruvate carboxylase from Escherichia coli11The coordinates and structure factors have been deposited in the Protein Data Bank (accession number 1QB4).

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    AbstractWe have determined the crystal structure of Mn2+-bound Escherichia coli phosphoenolpyruvate carboxylase (PEPC) using X-ray diffraction at 2.6 Å resolution, and specified the location of enzyme-bound Mn2+, which is essential for catalytic activity. The electron density map reveals that Mn2+ is bound to the side chain oxygens of Glu-506 and Asp-543, and located at the top of the α/β barrel in PEPC. The coordination sphere of Mn2+ observed in E. coli PEPC is similar to that of Mn2+ found in the pyruvate kinase structure. The model study of Mn2+-bound PEPC complexed with phosphoenolpyruvate (PEP) reveals that the side chains of Arg-396, Arg-581 and Arg-713 could interact with PEP

    研究グループ会の取り組みについて : ここ十数年の取り組みから <第2部 教科研究>

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    ここでいう研究グループ会とは広島県高等学校教育研究会数学部会福山支部研究グループ会のことである。略して研究グループ会ということにする。研究グループ会は昭和55年には存在していたようであるが定かではない。現在の研究グループ会につながる活動として記録に残るのは昭和58年で,当時は総会の際に管理職や退職された先生方に講演をしていただいていたようであるが, 「自前で数学的な活動がしたい」ということで研究グループ会の活動が始まったようである。我が校もこの研究グループ会の活動に当初から携わっていたようである。私(甲斐)がこの研究グループ会に加わったのは平成11年が最初である。それ以前も広島地区で研究グループ会に所属して話題提供や発表を行っていたが,福山地区に来てからはこの研究グループ会でほぼ欠かさずに話題提供や発表を行ってきている。ここではこの研究グループ会の活動について報告したい

    Electrofusion of Mesenchymal Stem Cells and Islet Cells for Diabetes Therapy: A Rat Model

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    膵島細胞と間葉系幹細胞の融合細胞を用いた糖尿病治療実験に成功 -新しい重症糖尿病治療法の開発に期待-. 京都大学プレスリリース. 2013-05-29.Islet transplantation is a minimally invasive treatment for severe diabetes. However, it often requires multiple donors to accomplish insulin-independence and the long-term results are not yet satisfying. Therefore, novel ways to overcome these problems have been explored. Isolated islets are fragile and susceptible to pro-apoptotic factors and poorly proliferative. In contrast, mesenchymal stem cells (MSCs) are highly proliferative, anti-apoptotic and pluripotent to differentiate toward various cell types, promote angiogenesis and modulate inflammation, thereby studied as an enhancer of islet function and engraftment. Electrofusion is an efficient method of cell fusion and nuclear reprogramming occurs in hybrid cells between different cell types. Therefore, we hypothesized that electrofusion between MSC and islet cells may yield robust islet cells for diabetes therapy. We establish a method of electrofusion between dispersed islet cells and MSCs in rats. The fusion cells maintained glucose-responsive insulin release for 20 days in vitro. Renal subcapsular transplantation of fusion cells prepared from suboptimal islet mass (1, 000 islets) that did not correct hyperglycemia even if co-transplanted with MSCs, caused slow but consistent lowering of blood glucose with significant weight gain within the observation period in streptozotocin-induced diabetic rats. In the fusion cells between rat islet cells and mouse MSCs, RT-PCR showed new expression of both rat MSC-related genes and mouse β-cell-related genes, indicating bidirectional reprogramming of both β-cell and MSCs nuclei. Moreover, decreased caspase3 expression and new expression of Ki-67 in the islet cell nuclei suggested alleviated apoptosis and gain of proliferative capability, respectively. These results show that electrofusion between MSCs and islet cells yield special cells with β-cell function and robustness of MSCs and seems feasible for novel therapeutic strategy for diabetes mellitus

    Improving Mathematics Lesson and Evaluation through Setting Inquiry Problem-Solving Activities

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    The purpose of this research is to make a theoretical framework for improving mathematics lesson and evaluation through setting inquiry problem-solving activities effectively in junior high and senior high mathematics lessons. To achieve this, we first carried out a questionnaire survey to capture how students perceive learning mathematics and, based on the results, made a framework incorporated these activities for lesson design and evaluation of student’s learning. Then, sample lesson conducted in a junior and senior high school based on the framework was analyzed to investigate its effectiveness and get some practical suggestions
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