249 research outputs found

    Joint Analysis of Static and Dynamic Importance in the Eye-Tracking Records of Web Page Readers

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    Heat maps highlight cumulative, static importance in eye-tracking records, while network analysis helps to elucidate dynamic importance from transitional relations. The present study was designed to perform both analyses in the same conceptual framework, i.e., network representation. For this purpose, heat maps comprising 5 × 5 segments were overlaid with networks, both of which were produced from the eye-tracking records of 20 subjects who read 10 top web pages that were classified into three layout types. The heat of the segments was graded on the basis of five percentile scores, whereas the core-peripheral nodes were identified by the agreement of centrality and ranking indices. The congruence between the two types of importance was generally good at the node level and the community levels. Additional findings included a) mixed patterns of the sustained fixations (i.e., loops) within the total fixations, and b) an increase in reciprocity as the network scope was narrowed to communities and then to the core neighborhoods

    Structural Comparisons of the Semantic Interface of the Top Cosmetic Brands on the Web by Network Analysis

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    Web presentations of consumer products serve as an interface between businesses and consumers. The present paperfocused on the verbal information on the webs of the top two skincare brands in Japan. Term by context matrices createdfrom the texts were truncated by SVD to construct graphs that represented high similarities among terms. In pursuit ofessential terms and the networks surrounding them, the primary clusters were decomposed in to communities in whichthe core nodes and their neighborhoods were identified. Though the brands differed greatly in concentrations of clusters,communities and neighborhoods, they showed similarities in the properties of cores. Of particular interest was the coreterm "plump" that appeared in both brands. Probably, this reflected the shared business awareness of the central concernabout skincare among the Japanese consumers. In lieu of conclusions, our plan of further inquiries were stated

    A Toulmin's Framework-Based Method for Design Argumentation of Cyber-Physical Systems

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    The design of cyber-physical systems (CPS) is a promising domain, where the data market is expected to soon penetrate. When engineers focus on only a particular part of data (whether intentionally or not) for establishing a design hypothesis, the design hypothesis may also be supported by data sets in the market. Therefore, the validity of such a design hypothesis cannot be evaluated by the data itself, and can only be accepted by the robustness of the logic behind the design argumentation. Although the validation of the design logic is significant, cognitive aspects (which people have spontaneously) disturb the design argumentation reasoning. Therefore, a design method that overcomes the cognitive aspects is indispensable for the CPS designers. This work proposes a CPS design method using the interaction between logic and data sets with a logic visualization tool, and applies the proposed method to the design of a diagnosis system for semiconductor manufacture. The capability of the proposed method is also discussed and analyzed in this paper

    Classification of Haptic Tasks based on Electroencephalogram Frequency Analysis

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    AbstractIn recent years, it is difficult to inherit high level sensory skill, because the number of experts is not so much or the experts are too busy to teach their skill to the beginners. Therefore, many learners do the experiential learning through visual and haptic digital teaching materials. In such a system, however, it is difficult to evaluate whether the learner could recognize the sensation and obtain the sensory skill. In the paper, we investigate whether the biological signal such as EEG can be used for the evaluation of the haptic task skill level

    MITOL assists Parkin in mitochondrial localization

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    PINK1 (PARK6) and PARKIN (PARK2) are causal genes of recessive familial Parkinson's disease. Parkin is a ubiquitin ligase E3 that conjugates ubiquitin to impaired mitochondrial proteins for organelle degradation. PINK1, a Ser/Thr kinase that accumulates only on impaired mitochondria, phosphorylates two authentic substrates, the ubiquitin-like domain of Parkin and ubiquitin. Our group and others have revealed that both the subcellular localization and ligase activity of Parkin are regulated through interactions with phosphorylated ubiquitin. Once PINK1 localizes on impaired mitochondria, PINK1-catalyzed phosphoubiquitin recruits and activates Parkin. Parkin then supplies a ubiquitin chain to PINK1 for phosphorylation. The amplified ubiquitin functions as a signal for the sequestration and degradation of the damaged mitochondria. Although a bewildering variety of Parkin substrates have been reported, the basis for Parkin substrate specificity remains poorly understood. Moreover, the mechanism underlying initial activation and translocation of Parkin onto mitochondria remains unclear, because the presence of ubiquitin on impaired mitochondria is thought to be a prerequisite for the initial PINK1 phosphorylation process. Here, we show that artificial mitochondria-targeted proteins are ubiquitylated by Parkin, suggesting that substrate specificity of Parkin is not determined by its amino acid sequence. Moreover, recruitment and activation of Parkin are delayed following depletion of the mitochondrial E3, MITOL/March5. We propose a model in which the initial step in Parkin recruitment and activation requires protein ubiquitylation by MITOL/March5 with subsequent PINK1-mediated phosphorylation. Because PINK1 and Parkin amplify the ubiquitin signal via a positive feedback loop, the low substrate specificity of Parkin might facilitate this amplification process

    Generation of monkey iPS cell-derived cartilage lacking MHC class I molecules on the cell surface

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    Multiple immune reactions when transplanting cartilage into monkeys. 京都大学プレスリリース. 2021-07-07.Due to the poor capacity for articular cartilage to regenerate, its damage tends to result in progressively degenerating conditions such as osteoarthritis. To repair the damage, the transplantation of allogeneic human induced pluripotent stem cell (iPSC)-derived cartilage is being considered. However, although allogeneic cartilage transplantation is effective, immunological reactions can occur. One hypothetical solution is to delete the expression of MHC class I molecules in order to reduce the immunological reactions. For this purpose, we deleted the β2 microglobulin (B2M) gene in a cynomolgus monkey (crab-eating monkey (Macaca fascicularis)) iPS cells (cyiPSCs) to obtain B2M⁻/⁻ cyiPSCs using the CRISPR/Cas9 system. Western blot analysis confirmed B2M⁻/⁻ cyiPSCs lacked B2M protein, which is necessary for MHC class I molecules to be transported to and expressed on the cell surface by forming multimers with B2M. Flow cytometry analysis revealed no B2M⁻/⁻ cyiPSCs expressed MHC class I molecules on their surface. The transplantation of B2M⁻/⁻ cyiPSCs in immunodeficient mice resulted in teratoma that contained cartilage, indicating that the lack of MHC class I molecules on the cell surface affects neither the pluripotency nor the chondrogenic differentiation capacity of cyiPSCs. By modifying the chondrogenic differentiation protocol for human iPSCs, we succeeded at differentiating B2M⁺/⁺ and B2M⁻/⁻ cyiPSCs toward chondrocytes followed by cartilage formation in vitro, as indicated by histological analysis showing that B2M⁺/⁺ and B2M⁻/⁻ cyiPSC-derived cartilage were positively stained with safranin O and expressed type II collagen. Flow cytometry analysis confirmed that MHC class I molecules were not expressed on the cell surface of B2M⁻/⁻ chondrocytes isolated from B2M⁻/⁻ cyiPSC-derived cartilage. An in vitro mixed lymphocyte reaction assay showed that neither B2M⁺/⁺ nor B2M⁻/⁻ cyiPSC-derived cartilage cells stimulated the proliferation of allogeneic peripheral blood mononuclear cells. On the other hand, osteochondral defects in monkey knee joints that received allogeneic transplantations of cyiPSC-derived cartilage showed an accumulation of leukocytes with more natural killer (NK) cells around B2M⁻/⁻ cyiPSC-derived cartilage than B2M⁺/⁺ cartilage, suggesting complex mechanisms in the immune reaction of allogeneic cartilage transplanted in osteochondral defects in vivo

    Generation of Monkey Induced Pluripotent Stem Cell-Derived Cartilage Lacking Major Histocompatibility Complex Class I Molecules on the Cell Surface

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    Due to the poor capacity for articular cartilage to regenerate, its damage tends to result in progressively degenerating conditions such as osteoarthritis. To repair the damage, the transplantation of allogeneic human induced pluripotent stem cell (iPSC)-derived cartilage is being considered. However, although allogeneic cartilage transplantation is effective, immunological reactions can occur. One hypothetical solution is to delete the expression of major histocompatibility complex (MHC) class I molecules to reduce the immunological reactions. For this purpose, we deleted the β2 microglobulin (B2M) gene in a cynomolgus monkey (crab-eating monkey [Macaca fascicularis]) iPS cells (cyiPSCs) to obtain B2M−/− cyiPSCs using the CRISPR/Cas9 system. Western blot analysis confirmed B2M−/− cyiPSCs lacked B2M protein, which is necessary for MHC class I molecules to be transported to and expressed on the cell surface by forming multimers with B2M. Flow cytometry analysis revealed no B2M−/− cyiPSCs expressed MHC class I molecules on their surface. The transplantation of B2M−/− cyiPSCs in immunodeficient mice resulted in teratoma that contained cartilage, indicating that the lack of MHC class I molecules on the cell surface affects neither the pluripotency nor the chondrogenic differentiation capacity of cyiPSCs. By modifying the chondrogenic differentiation protocol for human iPSCs, we succeeded at differentiating B2M+/+ and B2M−/− cyiPSCs toward chondrocytes followed by cartilage formation in vitro, as indicated by histological analysis showing that B2M+/+ and B2M−/− cyiPSC-derived cartilage were positively stained with safranin O and expressed type II collagen. Flow cytometry analysis confirmed that MHC class I molecules were not expressed on the cell surface of B2M−/− chondrocytes isolated from B2M−/− cyiPSC-derived cartilage. An in vitro mixed lymphocyte reaction assay showed that neither B2M+/+ nor B2M−/− cyiPSC-derived cartilage cells stimulated the proliferation of allogeneic peripheral blood mononuclear cells. On the contrary, osteochondral defects in monkey knee joints that received allogeneic transplantations of cyiPSC-derived cartilage showed an accumulation of leukocytes with more natural killer cells around B2M−/− cyiPSC-derived cartilage than B2M+/+ cartilage, suggesting complex mechanisms in the immune reaction of allogeneic cartilage transplanted in osteochondral defects in vivo.Okutani Y., Abe K., Yamashita A., et al. Generation of Monkey Induced Pluripotent Stem Cell-Derived Cartilage Lacking Major Histocompatibility Complex Class I Molecules on the Cell Surface. Tissue Engineering - Part A 28, 94 (2022); https://doi.org/10.1089/ten.tea.2021.0053

    Mammalian BCAS3 and C16orf70 associate with the phagophore assembly site in response to selective and non-selective autophagy

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    Macroautophagy/autophagy is an intracellular degradation process that delivers cytosolic materials and/or damaged organelles to lysosomes. De novo synthesis of the autophagosome membrane occurs within a phosphatidylinositol-3-phosphate-rich region of the endoplasmic reticulum, and subsequent expansion is critical for cargo encapsulation. This process is complex, especially in mammals, with many regulatory factors. In this study, by utilizing PRKN (parkin RBR E3 ubiquitin protein ligase)-mediated mitochondria autophagy (mitophagy)-inducing conditions in conjunction with chemical crosslinking and mass spectrometry, we identified human BCAS3 (BCAS3 microtubule associated cell migration factor) and C16orf70 (chromosome 16 open reading frame 70) as novel proteins that associate with the autophagosome formation site during both non-selective and selective autophagy. We demonstrate that BCAS3 and C16orf70 form a complex and that their association with the phagophore assembly site requires both proteins. In silico structural modeling, mutational analyses in cells and in vitro phosphoinositide-binding assays indicate that the WD40 repeat domain in human BCAS3 directly binds phosphatidylinositol-3-phosphate. Furthermore, overexpression of the BCAS3-C16orf70 complex affects the recruitment of several core autophagy proteins to the phagophore assembly site. This study demonstrates regulatory roles for human BCAS3 and C16orf70 in autophagic activity

    Classification by EEG Frequency Distribution in Imagination of Directions

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    AbstractThis paper describes the method for classification of brain state by the measured electroencephalogram (EEG) frequency in directions (up, down, left, and right) imagination. Recently, Brain-Machine Interface (BMI) has been studied in a variety of ways due to the development of brain measurement technology. Therefore, we have used the BMI to identify the human selection of directions. Our method consists of data normalization, principal component analysis and neural network. The maximum value of the identification rate was 46% by using 3 electrodes (F4, F8 and T8) in the previous study. In this study, we improved the learning method of neural network for the improvement of identification rate of brain state. For that purpose, the measurement points of EEG and the number of subjects are increased. As a result, the maximum value of the identification rate was improved

    A Tutoring for Behavior-Based Recursive Programming

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    プログラミングを行うためには,プログラムは少なくとも,プログラムの動作について明確に理解しておく必要がある.しかしながら初心者の場合プログラムの個々の命令の振舞いを理解できても,プログラム全体の動作を正しく理解できなかったり,プログラム仕様から動作を想定できない場合がよく見られる.このような初心者を対象とする場合,動作とプログラムコード,動作とプログラム仕様の対応関係について説明することが重要となる.本論文では動作の理解が特に難しい再帰プログラムを対象に,プログラムの動作を介したプログラミングを支援する知的教育システムについて述べる.筆者らは再帰プログラミングのモデルを想定した上で,学習者にとって理解が容易となるようにプログラムの動作を表現し,これをプログラムの振舞いと呼んでいる.本論文ではこの振舞い表現を用いて,再帰プログラムの設計過程および理解過程を支援する方法について論じる.特に,雛形を用いた解法による設計過程の支援ならびに,振舞い表現の可視化による理解過程の支援について述べる.更に振舞い表現の評価実験についても述べる
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