Universally Composable Undeniable Signature

How to define the security of undeniable signature schemes is a challenging task. This paper presents two security definitions of undeniable signature schemes which are more useful or natural than the existing definition. It then proves their equivalence. We first define the UC-security, where UC means universal composability. We next show that there exists a UC-secure undeniable signature scheme which does not satisfy the standard definition of security that has been believed to be adequate so far. More precisely, it does not satisfy the invisibility defined by \cite{DP96}. We then show a more adequate definition of invisibility which captures a wider class of (naturally secure) undeniable signature schemes. We finally prove that the UC-security against non-adaptive adversaries is equivalent to this definition of invisibility and the strong unforgeability in \cF_{ZK}-hybrid model, where \cF_{ZK} is the ideal ZK functionality. Our result of equivalence implies that all the known proven secure undeniable signature schemes (including Chaum\u27s scheme) are UC-secure if the confirmation/disavowal protocols are both UC zero-knowledge

Hyperplasia of lymphoid structures in the hypopharynx: a case report

<p>Abstract</p> <p>Introduction</p> <p>Ectopic tonsillar tissue simulating a benign tumor of the hypopharynx is described in this report.</p> <p>Case presentation</p> <p>We report the case of a 79-year-old Japanese woman with globus sensation. Because clinical observation revealed benign features, tumor tissue was laryngoscopically resected. From the pathological features, for example, existence of germinal center, lymphoid tissue, and crypt involving lymphoepithelial symbiosis, we diagnosed that the lesion was a hyperplasia of ectopic tonsillar tissue.</p> <p>Conclusions</p> <p>Although ectopic tonsillar tissue of the hypopharynx is relatively rare, it should be kept in mind during differential diagnosis.</p

インドネシア ノ チュウトウ キョウイク ムケ ニホンゴ キョウザイ サクセイ プロジェクト

本稿では、2003年から2007年までの予定で進行中のインドネシアの高校向け教材『にほんご1』『にほんご2』作成プロジェクトの計画・作成・評価の各段階について報告する。本プロジェクトでは、インドネシアの新カリキュラムに準拠し、教師にとって利用しやすい教材の開発をめざし、現職高校日本語教師、教育省、国際交流基金など多数の関係者が教材作成に取り組んだ。教材評価においては形成的評価を重視し、教師の利用状況を考慮した評価手法を採用した。最後に次の4点を大規模な利用が想定される教材の作成プロジェクト実施における留意点として提言した。1)教育行政当局との共同作業として進める。2)基本計画・目標をプロジェクト関係者全員で共有する。3)進捗の確認、問題の解決を速やかに図れる工夫を行い、要所要所で全体での進捗確認を行う。4)形成的評価、教材の利用状況を考慮した評価を盛り込む。This paper, which reports on a project of developing textbooks for high school students in Indonesia, was conducted between 2003 and 2007. The project consisted of three phases: Planning, Doing, and Seeing. The goal of this project was to develop materials to conform to the National Curriculum of Indonesia and to design them so that teachers can teach smoothly and effectively. The project has been conducted by high-school teachers; the Ministry of National Education, Indonesia; university teachers; and the Japan Foundation, Jakarta. As a result, four tips are recommended for conducting a project for developing materials that are expected to be widely. They are: 1) to work collaboratively with local authorities of education, 2) to share goals and schedules among all members; 3) to apply a tool for confirming progress and to share the information on progress periodically; and 4) to apply techniques of formative evaluation and situated evaluation

自閉症スペクトラム障害における近赤外線スペクトロスコピーを用いた表情認知機能の評価

One of the characteristics of Autism Spectrum Disorder (ASD) is social disorder. The specificity of facial and expression recognition for people with ASD is gathering attention as a factor of this social disorder. The study examined the hemodynamic activities in the prefrontal cortex using near-infrared spectroscopy (NIRS) when a person with ASD performed an expression recognition task. The subjects were twenty males (18 - 22 years old) with ASD and without intellectual disabilities. Forty-five healthy males matched for age and sex were included as a control group. In both groups, the degree of autistic tendencies was evaluated using the Autism-Spectrum Quotient (AQ). Using eight standard emotional expressions of Japanese people, two expression recognition tasks were set. An NIRS was used to measure the prefrontal cortex blood mobilization during the expression-processing process. The AQ was significantly higher in the ASD group, while the rate of overall correct expression response was significantly lower (p < 0.001). A negative correlation was found when the relationship between the AQ and the rate of overall correct expression response was evaluated by combining the results of the control group with those of the ASD group (ρ = −0.40 p < 0.001). In the automatic expression-processing task, no activation in the prefrontal cortex was found in either the ASD or the control group. In the conscious expression-processing task, the activation of the left and right lateral prefrontal cortex was weaker in the ASD group compared to the control group. Unlike in the control group, a mild activation of posterior prefrontal cortex was found in the ASD group. The expression-processing process of the ASD group was found to be different from that of the control group. NIRS was effective in detecting a brain function disorder in people with ASD during an expression-processing process

柿タンニンは新型コロナウイルスに対する抗ウイルス効果を持ち、シリアンハムスターモデルにおける新型コロナウイルス感染症の重症度および感染伝播を抑制する

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread across the world. Inactivating the virus in saliva and the oral cavity represents a reasonable approach to prevent human-to-human transmission because the virus is easily transmitted through oral routes by dispersed saliva. Persimmon-derived tannin is a condensed type of tannin that has strong antioxidant and antimicrobial activity. In this study, we investigated the antiviral effects of persimmon-derived tannin against SARS-CoV-2 in both in vitro and in vivo models. We found that persimmon-derived tannin suppressed SARS-CoV-2 titers measured by plaque assay in vitro in a dose- and time-dependent manner. We then created a Syrian hamster model by inoculating SARS-CoV-2 into hamsters' mouths. Oral administration of persimmon-derived tannin dissolved in carboxymethyl cellulose before virus inoculation dramatically reduced the severity of pneumonia with lower virus titers compared with a control group inoculated with carboxymethyl cellulose alone. In addition, pre-administration of tannin to uninfected hamsters reduced hamster-to-hamster transmission of SARS-CoV-2 from a cohoused, infected donor cage mate. These data suggest that oral administration of persimmon-derived tannin may help reduce the severity of SARS-CoV-2 infection and transmission of the virus.博士（医学）・甲第817号・令和4年3月15日© 2021. The Author(s). Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/

インドネシア ノ コウコウ ニホンゴ キョウシ ノ セイチョウ ヲ シエン スル キョウシ ケンシュウ プログラム

インドネシアの日本語学習者の70%以上が中等教育段階の学習者で占められるが、高校の日本語教育では、カリキュラム改訂が教育現場に与える影響が大きい。2004年カリキュラム改訂では、シラバス開発、教材の選択・作成など、学習者のニーズに合った教育の実践のために、教師に必要とされる能力の範囲が広くなった。国際交流基金ジャカルタ日本文化センターでは、高校の日本語教師を支援するために、カリキュラム開発、シラバス・教材開発、教師研修、教師会支援、学校訪問などのプログラムを教育省と連携して実施してきた。これらのプログラムの目的は、日本語教師の日本語力と教授力、教材開発力、そして日本語教育の自立化に必要な指導力、行政能力を向上させることにある。とくに、教師研修では、教師を成長させるために段階的なプログラムを作成している。本稿では、教師研修を中心にこれまでのプログラムの内容と成果について報告し、今後の方向を探る。More than 70% of the Japanese-language learners in Indonesia are senior secondary students. According to National Curriculum 2004 in Indonesia, teachers’ roles are becoming more important than in the former Curriculum. They have to co-ordinate their courses so that the courses become more communicative to fit the students’ needs. In cooperation with Department of Education in Indonesia, the Japan Foundation, Jakarta, has conducted programs to support teachers in such projects as curriculum development, teachertraining courses, and the developing of materials. Facilitating teachers’ development is the common objective of them all. In particular, teacher-training courses are designed in 4 levels so that the teachers might develop their expertise in the Japanese language, teaching methodology, administration, and leadership. As a result, a respectable amount of teachers gained expertise through this scheme. However, there is further need for evaluation of the current programs and continuous support for teachers

Gemcitabine-induced CXCL8 expression counteracts its actions by inducing tumor neovascularization

[email protected] with pancreatic ductal adenocarcinoma (PDAC) are frequently complicated with metastatic disease or locally advanced tumors, and consequently need chemotherapy. Gemcitabine is commonly used for PDAC treatment, but with limited efficacy. The capacity of gemcitabine to generate reactive oxygen species (ROS) in human pancreatic cancer cells, prompted us to examine its effects on the expression of pro-inflammatory cytokines and chemokines. We observed that gemcitabine enhanced selectively the expression of CXCL8 in human pancreatic cancer cells through ROS generation and NF-κB activation. In vitro blocking of CXCL8 failed to modulate gemcitabine-mediated inhibition of cell proliferation in human pancreatic cancer cells. Gemcitabine also enhanced CXCL8 expression in pancreatic cancer cells in xenografted tumor tissues. Moreover, anti-CXCL8 antibody treatment in vivo attenuated tumor formation as well as intra-tumoral vascularity in nude mice, which were transplanted with Miapaca-2 cells and treated with gemcitabine. Thus, gemcitabine-induced CXCL8 may counteract the drug through inducing neovascularization

Structural basis of Sec-independent membrane protein insertion by YidC

[プレスリリース]バイオサイエンス研究科膜分子複合機能学研究室の塚崎智也准教授らの研究グループが、タンパク質を細胞膜に組み込むメカニズムを解明しました（2014/04/17）Newly synthesized membrane proteins must be accurately inserted into the membrane, folded and assembled for proper functioning. The protein YidC inserts its substrates into the membrane, thereby facilitating membrane protein assembly in bacteria; the homologous proteins Oxa1 and Alb3 have the same function in mitochondria and chloroplasts, respectively1, 2. In the bacterial cytoplasmic membrane, YidC functions as an independent insertase and a membrane chaperone in cooperation with the translocon SecYEG3, 4, 5. Here we present the crystal structure of YidC from Bacillus halodurans, at 2.4 Å resolution. The structure reveals a novel fold, in which five conserved transmembrane helices form a positively charged hydrophilic groove that is open towards both the lipid bilayer and the cytoplasm but closed on the extracellular side. Structure-based in vivo analyses reveal that a conserved arginine residue in the groove is important for the insertion of membrane proteins by YidC. We propose an insertion mechanism for single-spanning membrane proteins, in which the hydrophilic environment generated by the groove recruits the extracellular regions of substrates into the low-dielectric environment of the membrane