1,720,980 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The chromosomal territory influencing the regulation of gene expression in neuronal cells
Full text linkヒト染色体工学技術を用いることで,神経細胞におけるヒト 15 番染色体の空間的配置と組織特異的遺伝子発現制御機構の解明に取り組んだ。その結果,PWS-IC 領域は活発な遺伝子発現を呈する遺伝子領域をヒト 15 番染色体テリトリーの外にループアウトする機能を持つことを見いだした。これらの結果から,ヒト 15 番染色体上の遺伝子は,染色体の空間的配置によって高度に制御されていることが明らかとなった。I examined the chromosome territory of a human chromosome 15 in neuronal cells by using the chromosome engineering techniques. Finally, I found that active gene region of 15q11-q13 was looping out from the chromosome 15 territory. From my results, 15q11-q13 locus was highly coordinately regulated by PWS-IC.研究課題/領域番号:23710215, 研究期間(年度):2011-2012出典：研究課題「染色体の空間的配置と組織特異的遺伝子発現制御機構の解明」課題番号23710215
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-23710215/23710215seika/）を加工して作成research repor
An epigenetic link between the DNA methylation and tissue-specific antigen expression in thymus
Full text link胸腺上皮細胞で強く発現しているAIREは、自己抗原の発現に関与していることが知られているがそのメカニズムは未だ明らかにされていない。そこで、我々は胸腺上皮細胞においてAireがエピジェネティックな制御機構を介して、自己抗原の発現に関与しているのではないかと考え、Ins2遺伝子座におけるDNAのメチル化やヒストン修飾について解析を行った。その結果、少なくとも解析した3つの領域においてDNAのメチル化レベルの違いは見られなかった。研究課題/領域番号:19790237, 研究期間(年度):2007-2008出典：「遺伝性自己免疫疾患のエピジェネティックス」研究成果報告書 課題番号19790237
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-19790237/19790237seika/)を加工して作成research repor
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Identification of chromatic factor which is associated with neuron specific chromatin dynamics
Full text link近年，細胞核内では転写マシナリーが活性化している領域と不活性化している領域とが存在し，遺伝子が適切な場所に配置されることで，発現が制御されることが明らかになっているが，実際にどのような分子が染色体ゲノムの核内配置や相互作用に関わり，遺伝子発現を制御しているのか，明らかにされていない。そこで，我々はプラダーウィリ症候群やアンジェルマン症候群の発症に寄与する15q11-q13領域に着目し，15q11-q13領域の遺伝子発現やクロマチンを制御する分子の同定を試みた。その結果，15q11-q13領域のクロマチン動態を司る分子として，メチル化CpG結合タンパク質の可能性が強く示唆された。The PWS/AS imprinted gene cluster on human chromosome 15q11-q13 spans ~4Mb region that includes several protein-coding genes and the 450kb long UBE3A-ATS lncRNA. UBE3A-ATS is expressed from its unmethylated CpG island promoter contained in the defined ICR on the paternal chromosome. Despite the fact that PWS-IC is known to be necessary for the coordinately controlled gene expression of 15q11-q13 imprinted domain, the mechanism by which it act and how it influence to the several protein-coding genes over long distance, is unknown. In order to define the precise long-range gene regulation of 15q11-q13, we examined shRNA-based knockdown experiments by using the human/mouse hybrid cells which is containing a single human chromosome of identified parental origin. Our results support the idea that Methyl-CpG binding proteinsuch as MeCP2, Mbd1 have an essential role for long-range gene regulation of 15q11-q13.研究課題/領域番号:25430167, 研究期間(年度):2013-04-01 - 2016-03-31出典：研究課題「神経細胞特異的なクロマチンダイナミクスを司る分子の同定」課題番号:25430167
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-25430167/25430167seika/）を加工して作成金沢大学学際科学実験センターresearch repor
Mechanism of the onset of autism by sex-specific epigenomic regulation
Full text linkIt seems that the factors causing sex differences in neurodevelopmental disorders such as autism, depression, and anxiety disorders involve a complex interplay of factors such as the involvement of genes on sex chromosomes and the influence of sex hormones on brain development during the fetal and neonatal periods. In the clinical trial of oxytocin for autism, a neurodevelopmental disorder, we have revealed that the effect of oxytocin administration is stronger in males and that the effect is very broad, ranging from a very large effect among males to almost no effect among males. In this study, we performed epigenomic analysis of the OXTR and AVPR genes to investigate the possibility of generating sex differences in the development of neurological disorders such as social and emotional disorders.自閉症やうつ病，不安障害などの神経発達障害における性差が生じる要因には，性染色体上の遺伝子の関与や胎児期・新生児期の脳の発達における性ホルモンの影響など複合的な要素が複雑に絡み合っていることが示唆されている。我々は，神経発達障害の一つである自閉症に対するオキシトシン臨床試験の過程で，オキシトシン投与の効果が男性に強く現れること，そして男性の中でも非常に大きく現れる者からほとんど効果を示さない者まで，非常にその効果が広範であることを明らかにしてきた。本研究課題ではOXTR遺伝子やAVPR遺伝子のエピゲノム解析を行い，社会性障害や情動障害などの神経疾患発症における性差を生み出す可能性を検討した。研究課題/領域番号:19K07365, 研究期間(年度):2019-04-01 - 2022-03-31出典：研究課題「性特異的なエピゲノム制御による自閉症発症機序の解明」課題番号19K07365
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/ja/report/KAKENHI-PROJECT-19K07365/19K07365seika/）を加工して作成金沢大学学際科学実験センターresearch repor
Neuron-specific impairment of inter-chromosomal pairing and transcription in a novel model of human 15q-duplication syndrome
Full text link本研究は,ヒト染色体工学技術を用いて自閉症患者で最も頻回に認められる15q11-q13領域の母方アレル特異的重複を再現し,「なぜ過剰な母方15q11-q13領域がUBE3A,ATP10C,GABAレセプター遺伝子群の発現量を低下させるか」を染色体ペアリングや染色体の核内配置といった高次クロマチン構造の視点から検討した。その結果,母方15q重複モデル細胞株においてGABRB3遺伝子やCHRNA7遺伝子の発現量の低下とともに,GABRB3遺伝子近傍での特異的な相同染色体のペアリングが消失していた。The most common recurrent cytogenetic abnormalities in autism spectrum disorders involve maternally derived duplications of the imprinted domain on chromosome 15q11-q13. Therefore characterizing the epigenetic chromatin organization of 15q11-q13 is important for understanding normal neuronal development. In this study, we focused on the homologous 15q11-q13 pairing in human neuronal cells. Our aim is to understand how the homologous pairing of 15q11-q13 is organized in the mammalian brain and associated with gene expression within the paired regions. In order to model 15q11-q13 maternal duplication in a neuronal cell line, a maternal copy of human chromosome 15 was transferred into the human SH-SY5Y neuronal cells by microcell fusion. As expected, homologous 15q11-q13 pairing was disrupted in human neuronal cells with an extra maternal copy of human chromosome 15. Interestingly, gene expression analysis of 15q11-q13 transcripts demonstrated significantly decreased expression of SNRPN, GABRB3, CHRNA7 transcripts despite increased maternal dosage. These results suggested that gene expression can be altered in unexpected ways through epigenetic changes resulting from increased maternal 15q11-13 dosage.出典：研究課題「15q11-13染色体ペアリングに着目した自閉症発症機構の解明」課題番号21710193
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-21710193/21710193seika/）を加工して作成金沢大学学際科学実験センターresearch repor
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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